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Home My WebLink AboutAtch 4 - 2009 walk-through audit Energy Audit Report Final Report August 8, 2009 City and Borough of Sitka Prepared for: Building Maintenance Department City and Borough of Sitka Prepared by: Alaska Energy Engineering LLC 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net This page intentionally left blank Alaska Energy Engineering LLC CBS Energy Audit 1 Table of Contents Table of Contents Table of Contents ...................................................................................... 1 Abbreviations ............................................................................................ 2 Section 1: Introduction 3 Introduction ........................................................................... 3 Methodology ......................................................................... 6 Section 2: Airport 11 Introduction ......................................................................... 11 Energy Consumption and Cost ............................................ 11 Description of Systems ........................................................ 12 Energy Conservation Opportunities .................................... 17 Summary ............................................................................. 28 Energy and Life Cycle Cost Data ........................................ 30 Section 3: Centennial Building 31 Introduction ......................................................................... 31 Energy Consumption and Cost ............................................ 31 Description of Systems ........................................................ 32 Energy Conservation Opportunities .................................... 38 Summary ............................................................................. 50 Energy and Life Cycle Cost Data ........................................ 52 Section 4: City Hall 53 Introduction ......................................................................... 53 Energy Consumption and Cost ............................................ 53 Description of Systems ........................................................ 54 Energy Conservation Opportunities .................................... 57 Summary ............................................................................. 63 Energy and Life Cycle Cost Data ........................................ 64 Section 5: Fire Hall 65 Introduction ......................................................................... 65 Energy Consumption and Cost ............................................ 65 Description of Systems ........................................................ 66 Energy Conservation Opportunities .................................... 70 Summary ............................................................................. 78 Energy and Life Cycle Cost Data ........................................ 80 Section 6: Library 81 Introduction ......................................................................... 81 Energy Consumption and Cost ............................................ 81 Description of Systems ........................................................ 82 Energy Conservation Opportunities .................................... 85 Summary ............................................................................. 92 Energy and Life Cycle Cost Data ........................................ 94 Alaska Energy Engineering LLC CBS Energy Audit 2 Table of Contents Table of Contents (continued) Section 7: Public Services Office/Shop Building 95 Introduction ......................................................................... 95 Energy Consumption and Cost ............................................ 95 Description of Systems ........................................................ 96 Energy Conservation Opportunities .................................. 101 Summary ........................................................................... 109 Energy and Life Cycle Cost Data ...................................... 111 Section 8: Senior Center 113 Introduction ....................................................................... 113 Energy Consumption and Cost .......................................... 113 Description of Systems ...................................................... 114 Energy Conservation Opportunities .................................. 117 Summary ........................................................................... 126 Energy and Life Cycle Cost Data ...................................... 127 Section 9: Wastewater Treatment Plant 129 Introduction ....................................................................... 129 Energy Consumption and Cost .......................................... 129 Description of Systems ...................................................... 129 Energy Conservation Opportunities .................................. 133 Summary ........................................................................... 140 Energy and Life Cycle Cost Data ...................................... 142 Section 10: Summary 143 Abbreviations ADA American’s with Disabilities Act CAV Constant air volume CBS City and Borough of Sitka CO2 Carbon dioxide CUH Cabinet unit heater DDC Direct digital controls DHW Domestic hot water DOAS Dedicated outside air system ECO Energy conservation opportunity EIFS Exterior insulation and finish system EF Exhaust fan EPS Expanded polystyrene EWT Entering water temperature FCU Fan coil unit Gal Gallon HPS High pressure sodium HVAC Heating, Ventilating, and Air- conditioning HW Hot water KVA Kilovolt-amps kW Kilowatt kWH Kilowatt-hour MBH 1,000 Btu per hour OS Occupancy sensor P Pump PSC Public Services Complex RF Return fan SF Supply fan TSA Transportation Security Administration UV Unit Ventilator VAV Variable air volume VFD Variable frequency drive VU Ventilating unit WWTP Wastewater Treatment Plant Alaska Energy Engineering LLC CBS Energy Audit 3 Introduction Section 1 Introduction INTRODUCTION This report presents the findings of a Level 1 (walk-through) energy audit of several City and Borough of Sitka (CBS) buildings. The walk-through was performed on April 6-10, 2009. The purpose of the energy audit is to identify energy conservation opportunities (ECOs) in each building. The findings were gathered through on-site observations, review of construction documents, and interviews with operation and maintenance personnel. The ECOs are evaluated using energy and life cycle cost analyses and priority ranked for implementation. Energy audits are categorized by the following three types: • Level 1 Walk-through: Involves a visual inspection of the building, preliminary interviews with operating personnel, and a brief review of energy and operational data to become familiar with the building operation and identify glaring areas of energy waste or inefficiency. Typically, only major problem areas will be uncovered during this type of audit. • Level 2 General Audit: Expands on the walk-through audit by collecting detailed operating data including monitoring energy systems. • Level 3 Comprehensive Audit: Expands the general audit by developing a computer model of the building, calibrating the model with energy use data, and using the model to accurately predict energy savings of ECOs. The walk-through energy audits are an appropriate level of effort for the buildings. These are relatively small, simple buildings with basic mechanical and lighting systems and minimal mechanical cooling. The audit process benefitted from comprehensive documentation of building construction and operating and maintenance data which facilitated incorporating some Level 2 effort into the project. The energy audit was performed by Jim Rehfeldt, P.E. of Alaska Energy Engineering LLC with the assistance of Chris Wilbur of the CBS Facilities Department. Buildings Energy audits were performed on the following buildings: • Airport • Centennial Building • City Hall • Fire Hall • Library • Public Services Office/Shop • Senior Center • Wastewater Treatment Plant (WWTP) Alaska Energy Engineering LLC CBS Energy Audit 4 Introduction Energy Consumption and Cost Six of the audited buildings consume fuel oil for space and domestic hot water heat and electricity for all other energy needs. Two of the buildings, City Hall and the Senior Center are all-electric buildings. The effective cost of electricity—sum of energy and demand charges—ranges from 9.1¢-10.3¢ per kWh. The Airport has the lowest cost due to long operating hours and steady electric loads. The Senior Center has the highest cost due to short operating hours and variable electric heating loads. The average cost is 9.4¢ per kWh. The following table compares the annual energy consumption and costs of the buildings. Annual Energy Consumption and Cost Building Fuel Oil, gallons Electricity, kWh Energy Cost Airport 18,000 31% 514,000 25% $88,000 26% Centennial Building 7,800 13% 240,000 12% $43,000 13% City Hall n/a - 380,000 18% $36,000 11% Fire Hall 10,000 17% 190,000 9% $42,000 12% Library 3,900 7% 96,000 5% $19,000 6% Public Services Offices 8,100 14% 54,000 3% $25,000 7% Senior Center n/a - 140,000 7% $14,000 4% WWTP 10,600 18% 460,000 22% $70,000 21% Totals 58,400 100% 2,074,000 100% $337,000 100% Note: Consumption is the average from 2003-2008. Costs are based on 2009 prices. The following table compares the energy use of each building. To provide a comparative tool, energy use is normalized by dividing the energy use by the building size and by the hours of occupancy to obtain a normalized energy use factor. Alaska Energy Engineering LLC CBS Energy Audit 5 Introduction Energy Use Comparison Energy Use Area Occupancy Normalized Building MMBTU sqft hrs/wk BTU/sqft/hr Airport 4,200 20,500 137 29 Centennial Building 1,900 21,600 89 19 City Hall 1,300 17,200 58 25 Fire Hall 2,000 15,900 168 15 Library 900 7,500 79 28 Public Services Offices/Shop 1,300 20,400 60 20 Senior Center 500 4,100 45 50 Totals/Average 12,100 107,200 92 26 The WWTP is not included because it has significant process loads that are unique to the building. Normalized Energy Use Factor (BTU/sqft/hr) = Energy Use / Area, sqft / occupied hours MMBTU = one million BTU In Southeast Alaska, ventilation air is typically the largest energy load. Efficient buildings have well insulated envelopes and right-sized energy systems that are capable of varying the ventilation rate with occupancy. The energy data reveals the following energy use comparison of the buildings: • Airport: The building uses the most energy because it is one of the largest and most highly occupied. The normalized energy use is high because the ventilation systems, which are sized for peak occupancy, are not operating efficiently during the many lightly occupied hours. • Centennial Building: The building is the largest and has high, variable occupancy. The normalized energy use is low because the envelope—while not optimally insulated—has minimal window area, and each room has a ventilation system that only operates when the room is in use. • City Hall: The building operates on a consistent schedule and occupancy, which should benefit its energy efficiency. However, it has a high normalized energy use because the control system has exceeded its useful life. The controls are not providing accurate control and do not employ modern strategies such as night setback and scheduled ventilation. • Fire Hall: The building is the only one that is occupied continuously. It has a low normalized energy use because it is a modern, well-insulated building with low occupancy. There is less priority to improve the energy efficiency of the building, but retro-commissioning the building to operate more efficiently during nights and weekends when less staff is present will reduce energy use. • Library: The building is one of the smaller buildings, has consistent hours and variable occupancy. The normalized energy use is high because the ventilation systems, which are sized for peak occupancy, are not operating at peak efficiency during the many lightly occupied hours. • Public Services Office/Shop: The building operates on a consistent schedule and occupancy, which should benefit its energy efficiency. The normalized energy use, while on the lower end, is limited by a below optimal thermal envelope and poor ventilation control. Alaska Energy Engineering LLC CBS Energy Audit 6 Introduction • Senior Center: The building is the smallest and has the lowest operating hours. The normalized energy use is highest, partially because of the energy demands of the commercial kitchen. A major contributor to the high energy use is a control system that has exceeded its useful life and is not properly scheduling the ventilation systems, providing night setback, or varying ventilation with occupancy and kitchen use. Several of the buildings have control systems that are not providing optimal control, especially of ventilation air. This is a common ECO, even in buildings like the Airport and Library, where the controls systems are relatively new and were installed to save energy. A combination of the following factors is likely the cause: • Optimal control sequences that are tailored to building operation are essential to energy efficiency. Too often, the designer does not understand how the building will be used so they develop generic sequences. • High energy prices have led to the development of more aggressive control strategies. Several of the buildings will benefit from scheduled ventilation (the amount of outside air is scheduled to match building occupancy) or demand control ventilation (CO2 sensors automatically vary outside airflow with occupancy) strategies, which were not in wide use just five years ago. • There is a renewed focus on commissioning buildings because many never worked properly when they were constructed. The commissioning process includes a review of the design and verification that the building operates efficiently. METHODOLOGY Energy Conservation Opportunities (ECOs) Energy conservation opportunities were identified by evaluating the building’s energy systems and comparing them to systems in modern, high performance buildings. The process for identifying the ECOs acknowledges the limitations of modifying existing buildings and systems, most of which were constructed when energy costs were much lower. The ECOs represent practical measures to improve the energy efficiency of the buildings. The process for identifying the ECOs acknowledges the realities of existing buildings that were constructed when energy costs were much lower. Many of the opportunities used in modern high performance buildings—highly insulated envelopes, variable capacity mechanical systems, heat pumps, daylighting, lighting controls, etc.—simply cannot be economically incorporated into existing buildings. Many ECOs promote optimizing modern, DDC control systems to provide thermal comfort and adequate indoor air quality while minimizing energy consumption. Where residential buildings can benefit from the simple capabilities of programmable thermostats to reduce energy consumption, DDC systems provide operators far greater capabilities to optimize the complex systems in commercial buildings. Heat pumps are capable of heating and cooling buildings at much greater efficiency than conventional systems. The efficiency gain can be an appealing 250-350%. Heat pumps are a viable technology that can provide a life cycle savings when incorporated into new construction. Alaska Energy Engineering LLC CBS Energy Audit 7 Introduction However, heat pumps are not proposed for any of the existing buildings. In buildings with existing hydronic heating systems, a major obstacle is that heat pumps operate at 110°F-120°F and boilers operate at 180°F-200°F. The high cost of converting the entire heating system so it can supply enough heat at the lower heat pump temperatures cannot be offset by the energy savings. For electric buildings, the high cost of replacing central ventilation systems with heat pumps and installing zone level heat pump heating units cannot be offset by energy savings. A major renovation of the buildings would offer opportunities to incorporate more energy efficiency opportunities common to high performance buildings into the existing buildings. Life Cycle Cost Analysis The ECOs are evaluated using life cycle cost analysis to determine if an energy efficiency investment will provide a savings over a 25-year life. The analysis incorporates construction, replacement, maintenance and repair, and energy costs to determine the total cost over the life of the ECO. Future maintenance and energy cash flows are discounted to present worth using escalation factors for general inflation, energy inflation, and the value of money. The methodology is based on the National Institute of Standards and Technology (NIST) Handbook 135 – Life Cycle Cost Analysis. Life cycle cost analysis is preferred to simple payback for facilities that have long—often perpetual— service lives. Simple payback, which compares construction cost and present energy cost, is reasonable for short time periods of 2-4 years, but yields below optimal results over longer periods because it does not properly account for the time value of money or the effect inflation has on operating budgets. Accounting for energy inflation and the cost of money properly values the true cost of facility ownership and seeks to minimize the total cost over its life. Construction Costs The cost estimates are derived based on a preliminary understanding of the scope of each ECO as gathered during the walk-through audit. The construction costs assume in-house labor at $60 for work typically performed by maintenance staff and contract labor for larger projects and electrical work. The estimates assume some efficiency gain by being incorporated into larger, energy efficiency or other construction projects. This will spread mobilization costs over a number of ECOs and minimize costs. When ECOs are taken for implementation, the cost estimate should be revisited once the scope and preferred method of performing the work has been determined. It is possible some ECOs will not provide a life cycle savings once the scope is finalized. Maintenance Costs Maintenance costs are based on in-house labor using historical maintenance efforts and industry standards. Maintenance costs Maintenance costs are determined for the 25-year life of each ECO are included in the life cycle cost calculation spreadsheets and represent realistic levels of effort to maintain the relative systems. Energy Analysis The energy performance of similar ECOs can vary dramatically between buildings. For example, the Airport has wider fluctuations in occupancy than City Hall. As such, the energy savings of demand control ventilation will be much greater. For this reason, the energy performance of an ECO is evaluated within the operating parameters of the building. Alaska Energy Engineering LLC CBS Energy Audit 8 Introduction A comprehensive energy audit would rely on a computer model of the building to integrate building energy systems and evaluate the energy savings of each ECO. The Level 1 audit does not utilize a computer model, so energy savings is calculated using integration factors to account for the dynamic operation of the building. Energy savings and costs are determined for the 25-year life of the ECO using appropriate factors for energy inflation. Prioritization A prioritized ranking of the ECOs was calculated for each building using the following formula: Prioritization Factor = Life Cycle Savings / Capital Costs This factor puts significant weight on the capital cost of an ECO, which is aligned with budgeting realities that allow early implementation of low cost improvements while higher cost ECOs must wait for funding and implementation. The ECOs are grouped into the following prioritized categories: • Behavioral or Operational: ECOs that need minimal capital investment but require operational or behavioral changes. A life cycle cost analysis is not performed of these ECOs because the energy savings is difficult to quantify and a life cycle savings is certain. • High Priority: ECOs that require a small capital investment and offer a life cycle savings. • Medium Priority: ECOs that require a significant capital investment to provide a life cycle savings. Some offer a substantial life cycle savings but require planning and investment to implement. Many medium priority ECOs return a high life cycle savings and offer substantial incentive to increase investment in building energy efficiency. • Low Priority: ECOs that will save energy but do not provide a life cycle savings. Economic Factors Economic factors are significant to the findings and should undergo careful scrutiny. • Nominal Interest Rate: This is the nominal rate of return on an investment without regard to inflation. The analysis uses a rate of 4.1%, which is the rate the CBS is currently receiving on invested finds. • Inflation Rate: This is the average inflationary change in prices over time. The analysis uses an inflation rate of 3.0%, which is the average of the consumer price index over the past 25-years. • Real Discount Rate: This is the actual rate of return with regard to inflation. The analysis uses a real discount rate of 1.1%, which is a calculated value, derived from the nominal interest rate and the inflation rate. • Economic Period: All costs are determined over the economic life of the ECO. The analysis is based on a 25-year economic period with construction beginning in 2009. Alaska Energy Engineering LLC CBS Energy Audit 9 Introduction Electricity Costs and Inflation Electricity is supplied by the CBS Electric Department. Power generation facilities include Blue Lake Hydro, Green Lake Hydro, and the Jarvis Street diesel plant. In 2008, the hydroelectric plants generated 97.6% of the electricity with diesel supplementation of the remaining amount. Each building is billed under the General Services rate, which charges for both electrical consumption (kWh) and peak electric demand (kW). Electrical consumption is the amount of energy consumed and electric demand is the rate of consumption. Electric demand is determined by averaging demand over a continuously sliding fifteen-minute window. The highest fifteen-minute average during the billing period determines the peak demand. The following table lists the current electric charges: General Service Rate Monthly Charge Rate Energy Charge per kWh First 500 kWh 14.17¢ 501 to 10,000 kWh 9.03¢ 10,001 to 100,000 kWh 8.50¢ Over 100,000 kWh 7.50¢ Demand Charge per kW First 25 kW No charge Over 25 kW $3.90 Over recent history, Sitka’s electricity inflation has been low, lagging general inflation. Even the diesel supplementation of recent years has not resulted in a rate increase. To reduce diesel supplementation, planning and preliminary design work is in progress to expand Blue Lake Hydro to its maximum capacity. That expansion will include raising the dam by as much as 83 feet, increasing power production of Blue Lake by over 50%. The Blue Lake project will be funded by 30-year bonds at market rate. The utility’s existing debt will be refinanced so the Blue Lake expansion will have a limited impact on rates over the next 20 years. However it is prudent to plan for nominal electric inflation of 1% per year. Even with the Blue Lake expansion, electric heating loads are likely to continue to place demands on the hydroelectric generation facilities. Energy balance reports for Southeast Alaska communities show that heating energy requirements are 175% of the electrical load. While most of the heating load is currently met with fuel oil, only a small percentage of this large potential load needs to convert to electricity to place demands on the electric grid. In essence, future electricity prices may be tied to fuel oil inflation. The life cycle cost analysis uses an electric inflation of 1.5%, which is higher than current predictions, to account for the costs of meeting future electric heating loads. Alaska Energy Engineering LLC CBS Energy Audit 10 Introduction Fuel Oil Costs and Inflation Halibut Point Marine Services currently supplies fuel oil to the CBS at a price of $2.40 per gallon of heating fuel. Fuel oil inflation has historically averaged 6% per year prior to the rapid escalation and de-escalation of prices over the past five years. The analysis assumes the fuel oil inflation will once again continue to inflate at 6% per year. Summary The following table summarizes the energy and economic factors used in the analysis. Summary of Economic and Energy Factors Factor Rate or Cost Factor Rate or Cost Nominal Discount Rate 4.1% Electricity Current rates General Inflation Rate 3.0% Electricity Inflation 1.5% Real Discount Rate 1.1% Fuel Oil Cost $2.40/gal Fuel Oil Inflation 6% Alaska Energy Engineering LLC CBS Energy Audit 11 Airport Section 2 Airport INTRODUCTION The Airport building contains public transportation spaces, airline support and administrative offices, vendor spaces, and a restaurant. The building is open year-round with flights starting at 6:00 am and ending near midnight. The building characteristics are: • Size: 20,500 square feet • Occupied Hours: 4:30 am to 12:00 midnight • Occupancy: Highly variable with flight schedules, peak of 300 occupants • HVAC Hours: 4:30 am to 12:00 midnight • Heating System: Fuel oil boiler and hydronic heating system with constant speed pumps • Ventilation Systems: Central air handling units with constant air flow • Domestic Hot Water System: Indirect hot water maker heated by boiler ENERGY CONSUMPTION AND COST The building energy sources are electricity and fuel oil. Fuel oil is consumed by the boiler to heat the building and domestic hot water and by the emergency generator. Electricity supplies all other loads. The following table summarizes the energy consumption and cost. Electricity use spreadsheets and graphs are at the end of this section. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Fuel Oil 18,000 gals $43,000 2,500 (58%) Electricity 514,000 kWh $45,000 1,800 (42%) Totals - $88,000 4,300 (100%) 1. Consumption is the average from 2003-2008. Costs are based on 2009 prices. MMBH = One Million BTUH Trends Fuel Oil: Annual usage decreased in 2007 and 2008 due HVAC and control renovations. Electricity: Electricity use was steady from 2004 to 2007 and dropped slightly in 2008. Electric demand is steady throughout the year, which indicates that demand control education is not needed. Electric demand dropped slightly in 2008 due to replacement of the Jetway and the HVAC systems. Effective cost—energy plus demand charges—is 9.1¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 8.5¢ per kWh. Energy consumption data is located at the end of this section. Alaska Energy Engineering LLC CBS Energy Audit 12 Airport DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Original No record n/a 1987 Expansion Gyp. Bd; 2x6 wd studs; R-19 batt; sheathing; cedar siding R-18 Roof High Bay (1987) Gyp. Bd; roof joists with batt insulation; metal roof R-38 Expansion (2003) Roof framing with batt insulation; built-up roof R-32 Main Roof (2007) Structure; ¾” plywood; 9-18” rigid; metal roof R-70 Floor Slab Concrete slab-on-grade R-2 Perimeter Concrete footing; 2” rigid; R-10 Windows Jetway Wood frame; single pane R-1.0 Main Entrance Metal frame w/o thermal break; single pane R-0.7 1987 Expansion Metal frame w/o thermal break; double pane R-1.5 Dining (2001) Vinyl frame; double pane, low-e, argon R-2.3 Hold Room (2001) Vinyl frame; double pane, low-e, argon R-2.3 Doors Main Entrance Metal frame w/o thermal break; single pane, poor weather-stripping R-0.5 Others w/o lite Metal frame w/o thermal break; poor weather-stripping R-3.0 Others w/ lite Metal frame w/o thermal break; double pane; poor weather-stripping R-2.0 Analysis Walls: The wall insulation is below optimal levels of R-25-30. Adding insulation to existing walls does not provide a life cycle savings due to the high cost of replacing interior or exterior surfaces. If the cladding is replaced, the investment in additional insulation will provide a life cycle energy savings. Roof: The main roof insulation level exceeds optimal levels. The high bay and expansion roof insulation is below optimal levels of R-50 to R-60. Adding insulation to the roof will not provide a life cycle savings due to the high cost of replacing the roof membrane. Adding roof insulation when the membrane is replaced will provide a life cycle savings. Floor Slab: The lack of floor slab insulation is typical of past practice and there is no economical way to add insulation to the floor slabs. Perimeter: The 2” thick perimeter insulation is typical of past practice and there is no economical way to add insulation to the perimeter. For new construction, today’s higher energy prices offer incentive to invest in thicker perimeter insulation. Windows: None of the windows is optimally insulated. There is incentive to replace single pane windows. Typically, replacing double pane windows does not offer a life cycle savings. Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken frames. Good weather-stripping that minimizes infiltration is essential to thermal performance. Alaska Energy Engineering LLC CBS Energy Audit 13 Airport Doors: None of the doors is optimally insulated. There is incentive to replace doors with single pane windows. Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken doors. Good weather-stripping that minimizes infiltration is essential to thermal performance. Other Items: • The baggage belt openings do not seal tightly when the belt is not operating. • The baggage belt passageway adjacent to the TSA area has openings in the thermal envelope. • The main entrance automatic door closures delay closing the doors for 9 seconds after the opening has cleared. A faster closing time will allow one door to seal the opening before the other door opens. • The restaurant entrance is moderately used but is not an arctic entrance. Heating System Description The heating system consists of an oil-fired, hot water boiler and hydronic distribution system. The hydronic heating system has a primary/secondary configuration where a primary pump circulates water through the boiler and secondary pumps distribute the water to the heating units. The primary and secondary pumps are constant speed pumps that have constant energy use without regard to the heating load. The heating units consist of heating coils in the ventilation systems, baseboard heaters, unit heaters, and radiant ceiling panels. The hydronic heating system is also connected to an indirect hot water heater that supplies domestic hot water. The heating system has the following pumps: • Primary pump P-4 circulates heating water through the boiler. • Secondary pump P-1 circulates heating water to the heating units. • Secondary pump P-2 circulates heating water through the SF-2 coil. • Secondary pump P-5 circulates heating water to the indirect hot water heater. Analysis The boiler is operated year-round to supply year-round heating loads that are the result of Sitka’s temperate climate. It is operating with an on-off temperature differential of 20°F. A large differential will decrease cycling losses and improve seasonal efficiency. The boiler does not have a flue damper to minimize the flow of heated air through the boiler and up the chimney when it is not operating. The pumps are manufactured by Grundfos. They are not as energy efficient as custom pumps with premium efficiency motors. Pump P-2 is not interlocked to turn off with SF-2. Converting the secondary system to variable speed pumping will decrease pumping costs by allowing pump energy consumption to vary with the heating load. None of the unit heaters has an automatic valve to shut off the heating water flow when heat is not required. Alaska Energy Engineering LLC CBS Energy Audit 14 Airport Ventilation System Description Supply Fan SF-1: SF-1 is an air handling unit that supplies constant flow mixed air to most of the building. The unit has a mixing box, filter section, heating coil, and supply fan. Return air flows through the ceiling plenum back to the mechanical room. Supply Fan SF-2 and EF-2: SF-2 is an air handling unit that supplies constant flow mixed air to the restaurant. The unit has a mixing box, filter section, heating coil, and supply fan. Return air is ducted back to the mixing box. EF-2 is a roof mounted exhaust fan that serves the kitchen hood. Supply Fan SF-3: SF-3 is an air handling unit hat supplies constant flow mixed air to the Air Taxi area within the building. The unit has a mixing box, filter section, heating coil, and supply fan. Return air flows through the ceiling plenum back to the mechanical room. Exhaust Fan EF-1: EF-1 is a utility fan that draws exhausts the air in the main toilet rooms. Exhaust Fan EF-3: EF-3 is a cabinet fan that exhausts air from the kitchen. Exhaust Fan EF-6: EF-6 is a wall propeller fan that exhausts air heated by the refrigeration compressors. Ventilating Unit VU-1: VU-1 is a cabinet fan that supplies cooling outside air to the boiler room. Analysis SF-1: • Optimally SF-1 would be a variable volume airflow system that modulates airflow with cooling loads. During the majority of the time when occupancy is light and outside temperatures are moderate, the fan would operate at lower flow rates, saving fan and reheat energy. • The outside air damper does not close tightly when the unit is off. SF-3: SF-3 is operated even though the air taxi area is little used. The unit can be turned off with little effect on indoor air quality. EF-1: There is no heat recovery from the toilet exhaust air. EF-2: The kitchen hood is a constant flow hood. Variable speed hoods are available that can be turned down during light cooking periods. EF-3: EF-3 is operating continuously but offers minimal cooling when compared to the EF-2 airflow rate. The unit was turned off. EF-6: There is no heat recovery of the rejected refrigeration heat. Cooling System Description The TSA baggage area has a cooling unit due to the high heat gain in the room. The cooling unit is a slit system with a fan and evaporator coil unit in the room and the condenser outside. Analysis The room can be adequately cooled for the majority of the year with a natural cooling system using outside air. Alaska Energy Engineering LLC CBS Energy Audit 15 Airport Domestic Hot Water System Description An indirect hot water heater supplies domestic hot water to the building. The heater setpoint is 130°F to meet kitchen hot water requirements. A thermostatic mixing valve provides anti-scald protection for non-kitchen uses. Domestic hot water recirculating pump P-3 maintains hot water in the distribution piping. The aerators on the toilet room faucets have a flow rate of 0.5 gpm. Automatic Control System Description The building HVAC systems are controlled by a Honeywell DDC system that interfaces with the City’s community-wide system and by local controls. Basic Control Sequences Boiler B-1: An operating thermostat turns the burner on at 155°F and off at 175°F. Primary Pump P-4: Manual starter with on-off switch controls the pump. Secondary pump P-1: Operates when outside temperature is below 75°F. Secondary pump P-2: The pump is interlocked to operate when SF-2 operates. Secondary pump P-5: Manual starter with on-off switch controls the pump. Heating Units: Room thermostats modulate the automatic valve to maintain the setpoint. Supply Fan SF-1: • The fan operates according to an occupied/unoccupied schedule. • The mixing dampers maintain a minimum of 10% outside air and modulate to maintain adequate CO2 levels in the North Lobby, South Lobby, and Hold Room. • In addition, the mixing dampers and heating coil automatic valve are modulated to maintain the heating supply setpoint. Supply Fan SF-2: • The fan operates according to an occupied/unoccupied schedule. • The mixing dampers maintain a minimum of 20% outside air. The dampers modulate to full outside air when EF-2 is operating. • The heating coil automatic valve is modulated to maintain the heating supply setpoint. Supply Fan SF-3: • The fan operates according to an occupied/unoccupied schedule. • The mixing dampers maintain a minimum of 10% outside air and modulate to maintain adequate CO2 level in the Air Taxi Lobby. • In addition, the mixing dampers and heating coil automatic valve are modulated to maintain the heating supply setpoint. Alaska Energy Engineering LLC CBS Energy Audit 16 Airport Exhaust Fan EF-1: EF-1 is interlocked to operate whenever SF-1 operates. Exhaust Fan EF-2: Manual starter with on-off switch controls the fan. Exhaust Fan EF-3: Manual starter with on-off switch controls the fan. Exhaust Fan EF-6: Manual starter with on-off switch controls the fan. Ventilating Unit VU-1: Room thermostat set at 78°F operates the fan to maintain the setpoint. TSA Cooling System: Room thermostat set at 67°F operates the unit to maintain the setpoint. Domestic Hot Water Heater WH-1: Immersion thermostat, set @ 130°F, controls pump P-5 to maintain the setpoint. Hot Water Recirculating Pump P-3: Operates according to an occupied/unoccupied schedule. Analysis Boiler B-1: Expanding the operating differential to 25°-30°F will decrease cycling and improve seasonal efficiency. Secondary Pump P-2: The pump is not properly interlocked with SF-2. SF-1: • The controls are not properly controlling the amount of ventilation air. On the day of the audit with 43°F outdoor temperature, it was supplying 38% outside air. • A reset control that changes the supply air temperature with cooling requirements will reduce reheating energy. • The mixed air and supply air controls are not working in tandem. The mixing air control is bringing in excess outside air to cool the mixed air temperature down to 60°F, which is causing the supply air control to add heat to raise the supply air temperature to the setpoint of 69°F. SF-2: • The controls are not properly controlling the amount of ventilation air. On the day of the audit with 43°F outdoor temperature, it was supplying 50% outside air with EF-2 off. • A reset control that changes the supply air temperature with cooling requirements will reduce reheating energy. • The mixed air and supply air controls are not working in tandem. The mixing air control is bringing in excess outside air to cool the mixed air temperature down to 55°F, which is causing the supply air control to add heat to raise the supply air temperature to the setpoint of 64°F. SF-3: • The controls are not properly controlling the amount of ventilation air. On the day of the audit with 43°F outdoor temperature, it was supplying 34% outside air. • A reset control that changes the supply air temperature with cooling requirements will reduce reheating energy. • The mixed air and supply air controls are not working in tandem. The mixing air control is bringing in excess outside air to cool the mixed air temperature down to 60°F, which is causing the supply air control to add heat to raise the supply air temperature to the setpoint of 70°F. Alaska Energy Engineering LLC CBS Energy Audit 17 Airport Lighting Description A project to upgrade the lighting and controls is currently in the design stage. The lighting is not included in the energy audit. Electric Equipment Description The building has 14 computers that are left on continuously. The kitchen has several refrigeration and freezer units. The Jetway has a 30 kVA transformer. There is a 100 kW emergency generator. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. The door gaskets on the kitchen refrigeration and freezer units are in poor condition, which allows exfiltration of the cold air. The refrigeration condenser coils are plugged with dirt, which reduces the efficiency of the units. This equipment is owned and maintained by the restaurant owner. ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. Airport-1: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Most of the airport lighting is not switched. The upcoming lighting upgrade project will include occupancy sensors to turn off lighting automatically. Lighting was left on in unoccupied rooms during the walk-through. Scope: Turning off lighting provides an immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. This ECO requires behavioral changes where occupants take responsibility for turning off lighting rather than leaving it continuously on. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 18 Airport Airport-2: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment provides an immediate payback. This ECO requires behavioral changes where occupants turn off equipment when they are finished. Analysis: This ECO is recommended without analysis. Airport-3: Adjust SF-1 Outside Air Damper Purpose: Fuel oil will be saved if the SF-1 outside air damper is adjusted so it seals closed when the fan is off. Scope: Adjust the damper actuator so it closed the damper completely when the fan is off. Analysis: This ECO is recommended without analysis. Airport-4: Increase Boiler Room Temperature Purpose: Fuel oil will be saved if the boiler room temperature is kept warmer. A warm boiler room uses the heat loss from the boiler and piping to preheat the combustion air. This improves the seasonal efficiency of the boiler. Scope: Ventilating Fan VF-1 is controlled by a thermostat set at 78°F to cool the boiler room. Increase the setpoint to a maximum of 90°F to preheat the combustion air. Analysis: This ECO is recommended without analysis. Airport-5: Reduce Entrance Temperatures Purpose: Fuel oil will be saved by reducing the temperature setpoints of the entrance heaters. The heaters are located near building entrances to dry the floor and to minimize the thermal comfort impact of cold air entering the building. The higher the temperature at the entrance the greater the amount of heat lost to the outdoors, whether the doors are open or closed. Reducing the temperature setpoint to the minimum needed for thermal comfort and moisture control will reduce heat loss. Scope: Entrance setpoints were educed in April, 2009 to 55°F. Adjust as needed. Mark the desired setpoint on the thermostat so it can be visually verified. Analysis: This ECO is recommended without analysis. Airport-6: Adjust Main Entrance Automatic Door Closures Purpose: Fuel oil will be saved if the main entrance automatic door closures are properly adjusted so the doors seal the opening soon after the passageway is clear. The automatic closures hold the doors open too long and both doors are open at the same time. Adjusting the closures to close quicker will reduce infiltration. Scope: Adjust the main entrance automatic door closures. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 19 Airport Airport-7: Replace Boiler Thermostat Purpose: Fuel oil will be saved if the boiler operating setpoints are changed so the boiler operates for a longer time during each cycle. The boiler operating thermostat has a fixed 20°F differential between on and off setpoints. A new controller that allows a 30°F differential will increase the amount of time the boiler operates when it is turn on, which improves seasonal efficiency. Scope: The boiler thermostat was replaced in June, 2009 with a model that has an adjustable temperature differential of 20-40°F. Set the differential as great as possible while supply sufficient heat. As a starting point, use typical differentials of 30°F in the winter and 40°F in the summer. Analysis: This ECO is recommended without analysis. Airport-8: Weather-strip Jetway Windows Purpose: Fuel oil will be saved if the windows are properly weather-stripped to reduce infiltration. The windows do not have weather-stripping. Scope: Install weather-stripping on the bottom edge of the operable windows. Analysis: This ECO is recommended without analysis. Airport-9: Weather-strip Exterior Doors Purpose: Fuel oil will be saved if doors are properly weather-stripped to reduce infiltration. Many of the doors do not have adequate weather-stripping. Scope: Install or repair the weather-stripping on most of the doors. The main entrance doors are the highest priority. Analysis: This ECO is recommended without analysis. Airport-10: Seal Baggage Belt Openings Purpose: Fuel oil will be saved if the baggage belt openings and passageway are sealed to reduce infiltration. The departure baggage opening has a curtain that does not seal the opening when it is not in use. The arrival baggage openings have doors and curtains, but neither seals the opening when it is not in use. The passageway has several open conduits and wallboard holes that allow infiltration into the building. Scope: Install an automatic door on the departure baggage openings. Design a closure for all openings that seals the opening when it is not in use. Seal the thermal envelope of the departure baggage passageway. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 20 Airport High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. Airport-11: Turn Off Supply Fan SF-3 Purpose: Fuel oil and electricity will be saved if supply fan SF-3 is turned off. SF-3 serves the back lobby area that is currently unoccupied. Turning the fan off will reduce ventilation air heating and fan energy. Scope: SF-3 was turned off in April, 2009. Analysis: This ECO reduces annual electricity use by 3,300 kWh, electric demand by 10 kW, fuel oil use by 220 gallons, and energy costs by $830. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 ($5,800) ($22,200) ($27,800) Note: Negative numbers, in parenthesis, represent savings. Airport-12: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Analysis: The airport has 14 computers. The analysis assumes that the computers are not in use for 8 hours of the day. The power settings were not checked on each machine, so the following analysis assumes that 25% of the computers are not set to enter sleep mode when inactive. Alaska Energy Engineering LLC CBS Energy Audit 21 Airport Setting the power settings from screen saver to sleep mode will reduce annual electricity use by 1,300 kWh and energy costs by $110. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 800 kWh and energy costs by $70. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $100 $0 ($2,000) ($1,900) Turn Off $200 $0 ($1,300) ($1,100) Total $300 $0 ($3,300) ($3,000) Note: Negative numbers, in parenthesis, represent savings. Airport-13: Install Unit Heater Automatic Valves Purpose: Fuel oil will be saved if each unit heater has an automatic valve that shuts off the hydronic flow when heat is not needed. The heater coil is continuously hot which results in convective heat loss when the heater fan is not operating. While some of the heat loss may be useful, it is often not. Scope: Install automatic valves in the heating supply to each unit heater. Analysis: For three unit heaters, this ECO reduces annual fuel oil use by 100 gallons and energy costs by $250. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $1,200 $0 ($8,000) ($6,800) Note: Negative numbers, in parenthesis, represent savings. Airport-14: Install Boiler Flue Damper Purpose: Fuel will be saved by installing a flue damper in the boiler flue. When the boiler is off, warm air escapes up the flue. A flue damper automatically closes the flue, reducing this heat loss. Scope: Install a flue damper in the boiler flue and control it to open prior to firing the boiler. Analysis: This ECO will improve the boiler seasonal efficiency by a minimum of 1% and reduce annual fuel oil use by 130 gallons and energy costs by $320. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $3,000 $1,300 ($10,200) ($5,900) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 22 Airport Medium Priority Medium priority ECOs require planning and a higher level of investment, but are viable because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. Airport-15: Install TSA Natural Cooling System Purpose: Electricity will be saved if the TSA Baggage screening room is naturally cooled with outside air instead of by mechanical cooling. Scope: Install a natural cooling air handling unit with mixing box to cool the TSA area. The natural cooling system will allow the TSA heat gain to be beneficial to the building rather than be discharged outside. The cooling air will be discharged to the building ceiling return plenum as preheated ventilation air, thus reducing the amount of OSA flow required by each supply fan. Analysis: This ECO will reduce annual electricity use by 2,900 kWh, electric demand by 11 kW, fuel oil use by 540 gallons, and energy costs by $1,600. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $9,500 ($3,900) ($46,600) ($41,000) Note: Negative numbers, in parenthesis, represent savings. Airport-16: Retro-commission HVAC Systems Purpose: Fuel and electricity will be saved if the HVAC systems are optimized through a retro- commissioning process. The energy audit revealed that the supply fans are over- ventilating, the Hold Room is fully ventilated during long periods when it is unoccupied, supply air reset controls are not in use, and ventilation controls are not being used. Scope: Retro-commission the building with a focus on the following: − Optimize automatic control strategies − Reduce minimum outside air flow − Utilize demand controlled ventilation (CO2 sensors) − Utilize supply air reset control − Utilize occupancy sensor control Analysis: The analysis conservatively assumes that retro-commissioning will reduce fuel oil use by 5% and electricity use by 0.8% This ECO will reduce annual electricity use by 4,200 kWh, fuel oil use by 1,200 gallons and energy costs by $3,200.The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $25,000 $0 ($97,500) ($72,500) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 23 Airport Airport-17: Install Refrigeration Waste Heat Recovery Purpose: Heat will be saved if the waste heat from the kitchen refrigeration units is transferred to the Dining Room instead of the current practice of discharging it outdoors. Scope: Install a ventilating fan and thermostat control to transfer air heated by the refrigeration units to the Dining Room. Analysis: This ECO will reduce annual fuel oil use by 410 gallons and energy costs by $950. In addition, removing the heat from the condenser room will improve refrigeration efficiency. This efficiency gain is not included in the energy savings because it is difficult to quantify. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $7,500 $2,600 ($30,600) ($20,500) Note: Negative numbers, in parenthesis, represent savings. Airport-18: Install Jetway Lighting Occupancy Sensors Purpose: Electricity will be saved if the Jetway lighting is turned off when it is not being used. The lighting is currently on continuously, but the Jetway is used 5 hours per day during the summer months and 3 hours per day the rest of the year. An occupancy sensor can control the lighting so it is on only when needed. Scope: Occupancy sensors will be installed in the Jetway in a 2010 lighting upgrade project. Analysis: This ECO will reduce annual electricity use by 7,900 kWh and energy costs by $680. In addition, it will increase lamp life and reduce replacement costs. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $4,000 ($400) ($12,300) ($8,700) Note: Negative numbers, in parenthesis, represent savings. Airport-19: Replace Entrance Window and Door Glazing Purpose: Heat will be saved if the single pane glazing in the outer entrance windows and doors is replaced with double pane glazing units. Scope: Replace single pane glazing units in the outer entrance windows and doors with insulating glazing units installed in the existing metal frames. Analysis: This ECO will reduce annual fuel oil use by 420 gallons and energy costs by $1,000. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $15,900 $0 ($32,100) ($16,200) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 24 Airport Airport-20: Replace Jetway Windows Purpose: Heat will be saved if the older, less efficient windows are replaced with efficient glazing units. Scope: Replace single pane wood windows with triple pane vinyl windows. Analysis: This ECO will reduce annual fuel oil use by 35 gallons and energy costs by $85. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $1,700 $0 ($2,700) ($1,000) Note: Negative numbers, in parenthesis, represent savings. Airport-21: Replace Transformer Purpose: Electricity will be saved if the transformer in the Jetway is replaced with an energy efficient transformer that complies with NEMA Standard TP 1-2001. Scope: Replace a 30 KVA transformer in the Jetway with a NEMA Standard TP 1- 2001compiant model. Analysis: This ECO will reduce annual electricity use by 7,100 kWh, electric demand by 10 kW, and energy costs by $640. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $7,500 $0 ($11,700) ($4,200) Note: Negative numbers, in parenthesis, represent savings. Airport-22: Variable Hold Room Air Flow Purpose: Electricity will be saved by closing off the airflow to the Hold Room when the room is unoccupied. Scope: Install a VFD on SF-1 and control it from a pressure sensor in the distribution ductwork. Install a variable volume terminal box in the supply duct serving the Hold Room and control it from room occupancy sensors. Analysis: The Hold Room is occupied for 5 hours per day during the summer and 3 hours per day the rest of the year. Fan power is reduced most of the day by turning off the airflow to the room and reducing the output of SF-1. This ECO will reduce annual electricity use by 9,800 kWh and energy costs by $830. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $11,800 $2,600 ($15,200) ($800) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 25 Airport Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. Airport-23: Convert to Variable Speed Hydronic Pumping Purpose: Electricity will be saved if the hydronic heating system is converted to variable speed pumping. Scope: Install a VFD and pressure sensor to control Pump P-1. Convert the hydronic heating system to variable speed operation. Analysis: Variable speed pumping allows the pumps to operate at lower power when less hydronic flow is needed. While a constant speed pump consumes full power at all operating conditions, a variable speed pumping system will consume 50%-75% less power. Converting the hydronic heating system to variable speed will require replacing three-way control valves with two-way valves and integrating the control system. These costs are not offset by the energy savings. Variable speed pumping would have provided a life cycle savings if the building was being newly constructed. This ECO will reduce annual electricity use by 9,500 kWh, electric demand by 10 kW, and energy costs by $840. The following table summarizes the life cycle cost analysis. This ECO is not recommended. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $13,500 $2,600 ($15,400) $700 Note: Negative numbers, in parenthesis, represent savings. Airport-24: Replace Grundfos Pumps P-1 and P-4 Purpose: Electricity will be saved if the Grundfos pumps are replaced with custom pumps with NEMA Premium® Motors. Scope: Replace pumps P-1 and P-4 with custom pumps. Analysis: Grundfos pumps are more reliable and maintenance free and are easily replaced when they fail. However, they are less energy efficient than custom pumps because they are not customized to the system operating condition. In addition, the integral motors are less efficient than NEMA Premium® motors. The energy savings of the custom pumps is more than offset by installation and maintenance costs so that replacement does not offer a life cycle savings. This ECO will reduce annual electricity use by 5,000 kWh, electric demand by 7 kW, and energy costs by $450. The following table summarizes the life cycle cost analysis. This ECO is not recommended. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $4,500 $5,200 ($8,300) $1,400 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 26 Airport Airport-25: Add Exhaust Air Heat Recovery Purpose: Heat will be saved if heat is recovered from the EF-1 exhaust air and used to preheat the AHU-1 ventilation air. Analysis: EF-1 exhausts 1,370 cfm from the toilet rooms. Installing a heat recovery loop and heat recovery coils in SF-1 and EF-1 will transfer heat from the exhaust airflow to the ventilation air into SF-1. This ECO will reduce annual fuel oil use by 1,700 gallons and energy costs by $4,000. This energy savings has a life cycle value of $113,000. However, there is insufficient space to add heat recovery coils to SF-1 and EF-1, and the existing fans do not have the capacity to handle the added air pressure drop through the heat recovery coils. This result is typical as it is often difficult to incorporate heat recovery into an existing building. This ECO is not recommended. Airport-26: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand is very steady so there is little need to educate people on demand control. Airport-27: Replace Non-thermally Broken Metal Doors Purpose: Heat will be saved if non-thermally broken doors are replaced with thermally broken units. Most of the doors are non-thermally broken. Analysis: Thermally broken doors and frames have separators between the inside and outside surfaces so there is not a direct conductive path through the metal. The thermal break reduces heat loss and keeps inner surfaces warmer, which precludes the formation of condensation. Previous analyses have shown that replacing the doors will not provide a life cycle savings. This ECO is not recommended. Airport-28: Increase Wall Insulation Purpose: Heat will be saved if the insulation level of the walls is increased. Analysis: The walls are constructed of 2x6 wood studs with batt insulation. They have an R-19 R-value, which was optimal when the building was renovated in 1987. An optimal R- value at current fuel oil prices is likely to be R-24 to R-30. Since the walls are moderately insulated, adding insulation will not provide sufficient energy savings to offset the cost of replacing the interior walls board or exterior cladding. If cladding replacement is needed in the future, adding insulation will provide a life cycle savings. This ECO is not recommended. Airport-29: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 27 Airport Airport-30: Install Variable Speed Kitchen Hood Purpose: Heat and electricity will be saved if the kitchen hood is replaced with a variable speed hood. Analysis: Variable speed kitchen hoods are listed for reduced airflow during non-peak cooking periods. Replacing the existing hood with a variable flow hood will not provide a life cycle savings because the high cost of replacing the hood and exhaust fan will not be offset by future energy savings. This ECO is not recommended. Airport-31: Add Arctic Entrance: Restaurant entrance Purpose: Heat will be saved if the building entrance near the restaurant is converted to an arctic entrance. Analysis: Arctic entrances require passage through two doors to enter/leave the building. By locating the doors with sufficient space between them, one of the doors is closed when the other is open, sealing the entrance and reducing infiltration. There is insufficient space to add an arctic entrance to the entrance. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 28 Airport SUMMARY Energy Analysis The following table shows the projected energy savings of the ECOs. Annual Energy Cost Savings Fuel Oil Electricity Total Current Energy Costs $43,000 $45,000 $88,000 Behavioral and Operational Airport-1: Turn Off Lighting Airport-2: Turn Off Equipment Airport-3: Adjust SF-1 Outside Air Damper Airport-4: Increase Boiler Room Temperature Airport-5: Reduce Entrance Temperatures Airport-6: Adjust Main Entrance Automatic Door Closures Airport-7: Replace Boiler Thermostat Airport-8: Weather-strip Jetway Windows Airport-9: Weather-strip Exterior Doors Airport-10: Seal Baggage Belt Openings Energy Savings (Estimated) ($340) ($90) ($430) High Priority Airport-11: Turn Off SF-3 ($520) ($320) ($840) Airport-12a: Set Computers to Sleep Mode $0 ($110) ($110) Airport-12b: Turn Off Inactive Computers $0 ($70) ($70) Airport-13: Install Unit Heater Automatic Valves ($250) $0 ($250) Airport-14: Install Boiler Flue Damper ($320) $0 ($320) Medium Priority Airport-15: Install TSA Natural Cooling System ($1,300) ($290) ($1,590) Airport-16: Retro-commission HVAC Systems ($2,900) ($360) ($3,260) Airport-17: Install Refrigeration Waste Heat Recovery ($980) $30 ($950) Airport-18: Install Jetway Lighting Occupancy Sensors $0 ($680) ($680) Airport-19: Replace Entrance Window and Door Glazing ($1,000) $0 ($1,000) Airport-20: Replace Jetway Windows ($80) $0 ($80) Airport-21: Replace Transformers $0 ($640) ($640) Airport-22: Variable Hold Room Air Flow $0 ($830) ($830) ECO Savings ($7,690) ($3,360) ($11,050) (18%) (7%) (13%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 29 Airport Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational Airport-1: Turn Off Lighting $0 Airport-2: Turn Off Equipment $0 Airport-3: Adjust SF-1 Outside Air Damper $0 Airport-4: Increase Boiler Room Temperature $50 Airport-5: Reduce Entrance Temperatures $100 Airport-6: Adjust Entrance Auto Door Closures $150 Airport-7: Replace Boiler Thermostat $200 Airport-8: Weather-strip Jetway Windows $600 Airport-9: Weather-strip Exterior Doors $1,400 Airport-10: Seal Baggage Belt Openings $ 7,500 Totals $10,000 $0 ($12,600) ($2,600) High Priority Airport-11: Turn Off SF-3 $200 ($5,800) ($22,200) ($27,800) Airport-12a: Set Computers to Sleep Mode $100 $0 ($2,000) ($1,900) Airport-12b: Turn Off Inactive Computers $200 $0 ($1,300) ($1,100) Airport-13: Install Unit Heater Auto Valves $1,200 $0 ($8,000) ($6,800) Airport-14: Install Boiler Flue Damper $3,000 $1,300 ($10,200) ($5,900) Medium Priority Airport-15: Install TSA Natural Cooling System $9,500 ($3,900) ($46,600) ($41,000) Airport-16: Retro-commission HVAC Systems $25,000 $0 ($97,500) ($72,500) Airport-17: Install Refrigeration Heat Recovery $7,500 $2,600 ($30,600) ($20,500) Airport-18: Install Jetway Occupancy Sensors $4,000 ($400) ($12,300) ($8,700) Airport-19: Replace Main Entrance Glazing $15,900 $0 ($32,100) ($16,200) Airport-20: Replace Jetway Windows $1,700 $0 ($2,700) ($1,000) Airport-21: Replace Transformers $7,500 $0 ($11,700) ($4,200) Airport-22: Variable Hold Room Air Flow $11,800 $2,600 ($15,200) ($800) Totals $97,600 ($3,600) ($305,000) ($211,000) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 30 Airport ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic fuel oil consumption • Historic electricity use • Energy and life cycle cost analysis calculations 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 0 5,000 10,000 15,000 20,000 25,000 2003 2004 2005 2006 2007 2008 Degree DaysGallonsFuel Oil Consumption Gallons Degree Days Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 49,440 80 41,080 76 42,040 78 42,800 77 175,360 Feb 43,120 78 40,960 75 43,320 78 39,560 76 166,960 Mar 40,840 77 38,520 78 38,440 83 46,160 78 163,960 Apr 38,400 76 42,800 75 48,640 78 43,640 72 173,480 May 45,280 71 40,240 76 43,640 81 37,600 75 166,760 Jun 39,980 73 40,120 78 45,800 77 45,440 73 171,340 Jul 39,980 74 46,920 74 40,320 76 40,440 72 167,660 Aug 47,680 73 44,720 77 43,280 78 41,840 70 177,520 Sep 39,240 72 39,560 75 47,000 77 42,240 73 168,040 Oct 43,520 74 47,080 78 40,320 76 46,320 74 177,240 Nov 42,480 77 43,680 80 44,280 77 39,600 74 170,040 D 45 880 80 46 560 80 44 280 78 40 800 78 177 520 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 45,880 80 46,560 80 44,280 78 40,800 78 177,520 Total 515,840 512,240 521,360 506,440 513,970 Average 42,987 75 42,687 77 43,447 78 42,203 74 42,831 Load Factor 78.0% 76.1% 76.2% 77.8% 76 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 3,652 208 3,860 3,717 202 3,919 1.5% Feb 3,761 207 3,968 3,441 199 3,640 -8.3% Mar 3,346 225 3,572 4,002 205 4,207 17.8% Apr 4,213 207 4,420 3,788 183 3,971 -10.1% May 3,788 218 4,006 3,275 194 3,469 -13.4% Jun 3,972 204 4,175 3,941 186 4,128 -1.1% Jul 3,506 200 3,706 3,516 183 3,699 -0.2% Aug 3,758 205 3,963 3,635 177 3,812 -3.8% Sep 4,074 202 4,276 3,669 188 3,857 -9.8% Oct 3,506 199 3,705 4,016 191 4,207 13.6% Nov 3,843 202 4,045 3,445 191 3,636 -10.1% Dec 3,843 207 4,049 3,547 207 3,753 -7.3% Total $ 45,260 $ 2,484 $ 47,744 $ 43,992 $ 2,307 $ 46,299 -3.0% Average $ 3,772 $ 207 $ 3,979 $ 3,666 $ 192 $ 3,858 -3.0% Cost ($/kWh) 0.0916 95% 5% 0.0914 -0.2% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 0 10,000 20,000 30,000 40,000 50,000 60,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 0 0 0 0 0 0 0 0 0 0 0 0 10,000 20,000 30,000 40,000 50,000 60,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 10 20 30 40 50 60 70 80 90 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 $ 3,000 $ 3,500 $ 4,000 $ 4,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 $ 3,000 $ 3,500 $ 4,000 $ 4,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 66 68 70 72 74 76 78 80 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Qty Unit Base Cost Year 0 Cost Construction Costs Airport-1: Turn Off Lighting 1 job $0 $0 Airport-2: Turn Off Equipment 1 job $0 $0 Airport-3: Adjust SF-1 Outside Air Damper 1 job $0 $0 Airport-4: Increase Boiler Room Temperature 1 job $50 $50 Airport-5: Reduce Entrance Temperatures 1 job $100 $100 Airport-6: Adjust Main Entrance Automatic Door Closures 1 job $150 $150 Airport-7: Replace Boiler Thermostat 1 job $200 $200 Airport-8: Weather-strip Jetway Windows 1 job $600 $600 Airport-9: Weather-strip Exterior Doors 1 job $1,400 $1,400 Airport-10: Seal Baggage Belt Openings 1 job $7,500 $7,500 Energy Costs Electric Energy 1 - 25 -1,059 kWh $0.085 ($1,646) Fuel Oil 1 - 25 -142 gal $2.40 ($10,906) Net Present Worth ($2,552) Airport-11: Turn Off SF-3 Energy Analysis August 8, 2009 Year 0 0 0 0 0 0 0 0 0 0 Energy Analysis OSA CFM Tosa Tsa Hours/day Boiler Effic Fuel, gals 230 45 65 11 70% -215 CFM ΔP HP kW kWh -2,305 1.5 -1.1 -0.8 -3,259 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Turn off fan and drain coil 1 ea $200 $200 Annual Costs Fan maintenance 1 - 25 -2 hrs $60.00 ($2,592) Filter replacement 1 - 25 -3 ea $50.00 ($3,240) Energy Costs Electric Energy 1 - 25 -3,259 kWh $0.085 ($5,066) Electric Demand 1 - 25 -10 kW $3.90 ($695) Fuel Oil 1 - 25 -215 gal $2.40 ($16,453) Net Present Worth ($27,846) Hours/Day 0 Heat, kBTU -20,316 11 Year Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 Airport-12a: Set Computers to Sleep Mode Energy Analysis Number Watts Hours/day Day/yr kWh Factor kWh 14 -125 8 365 -5,110 25% -1,278 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Change computer settings 1 job $100 $100 Energy Costs Electric Energy 1 - 25 -1,278 kWh $0.085 ($1,986) Net Present Worth ($1,886) Airport-12b: Turn Off Inactive Computers Energy Analysis Number Watts Hours/day Day/yr kWh 14 -20 8 365 -818 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Change computer settings 1 job $200 $200 Energy Costs Electric Energy 1 - 25 -818 kWh $0.085 ($1,271) Net Present Worth ($1,071) Airport-13: Install Unit Heater Automatic Valves EAli kW -0.3 Year kW -1.8 Year 0 0 Energy Analysis Loss, BTUH Number Factor Loss, kBTU Fuel, gals -1,500 3 25% -9,855 -104 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install AV and controls 3 ea $400 $1,200 Energy Costs Fuel Oil 1 - 25 -104 gal $2.40 ($7,981) Net Present Worth ($6,781) Airport-14: Install Boiler Flue Damper Energy Analysis Input, gph FO Gallons On Hours Off Hours CFM w/damper kBTU Boiler Effic Fuel, gals 9.1 18,200 1,998 6,762 5 -12,645 70% -134 99% Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install flue damper 1 ea $3,000 $3,000 Annual Costs Flue damper maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Fuel Oil 1 - 25 -134 gal $2.40 ($10,240) Net Present Worth ($5,944) Boiler Effic 70% CFM w/o damper Year 0 Year 0 15 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 Airport-15: Install TSA Natural Cooling System Energy Analysis Option A/C MBH COP kW Load Factor kWh Exist A/C 18 3.5 -1.5 50% -4,400 New A/C 18 3.5 1.5 50% 137 New AHU - - 0.2 50% 1,393 Savings -11 -2,870 CFM Trm Tosa MBH kBTU η, boiler Fuel, gals -700 68 41 -20 -51,030 70% -540 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Natural cooling air handler, ductwork, electrical 1 ea $9,500 $9,500 Annual Costs Reduced A/C unit maintenance 1 - 25 -4 hrs $60.00 ($5,185) AHU maintenance 1 - 25 1 hrs $60.00 $1,296 Energy Costs Electric Energy 1 - 25 -2,870 kWh $0.085 ($4,462) Electric Demand 1 - 25 -11 kW $3.90 ($809) Fuel Oil 1 - 25 -540 gal $2.40 ($41,326) Net Present Worth ($40,986) Airport-16: Retro-commission HVAC Systems Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Year Hours/Day 16 15.5 0 Year 0.5 Hours/yr 2,500 Construction Costs Develop control sequences 1 ea $4,000 $4,000 Automatic control modifications 2 pts $1,500 $3,000 Retro-commissioning Modify control drawings 16 hrs $140 $2,240 Modify control software 16 hrs $140 $2,240 On-site Implementation and travel, including commissioning 40 hrs $140 $5,600 Perdiem and Travel 1 ea $2,500 $2,500 Closeout 16 hrs $140 $2,240 Verification 1 ea $3,000 $3,000 Energy Costs Electric Energy 1 - 25 -4,235 kWh $0.085 ($6,585) Fuel Oil 1 - 25 -1,188 gal $2.40 ($90,880) Net Present Worth ($72,645) 0 0 0 0 0 0 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 Airport-17: Install Refrigeration Waste Heat Recovery Energy Analysis kW EER Heat, MBH Hours kBTU η,boiler Fuel, gals -2 10 -20 5,840 -38,544 70% -408 Fan CFM ΔP η, fan BHP kW Hours kWh 900 0.5 45% 0.16 0.15 1,927 283 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Ventilating fan and ductwork 1 ea $6,500 $6,500 Reconfigure refrigeration condenser 1 ea $1,000 $1,000 Annual Costs Fan maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 283 kWh $0.085 $440 Electric Demand 1 - 25 2 kW $3.90 $126 Fuel Oil 1 - 25 -408 gal $2.40 ($31,215) Net Present Worth ($20,557) Airport-18: Install Jetway Lighting Occupancy Sensors Energy Analysis # Fixtures watts/ea Hours, exist Hours,os Lamp Cost Lamp Hours Lamp $/yr 13 108 6,935 1,278 3.50 10,000 $0.45 Lif C l C A l i Q Ui BC Y0C η, motor 80% Load Factor 33% kWh -7,943 Y Year 0 0 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install occupancy sensor 2 ea $2,000 $4,000 Annual Costs Decrease lamp replacement costs 1 - 25 -39 lamps $0.45 ($377) Energy Costs Electric Energy 1 - 25 -7,943 kWh $0.085 ($12,349) Net Present Worth ($8,726) Airport-19: Replace Entrance Window and Door Glazing Energy Analysis Room R,old R,new Area, sqft kBTU η, boiler Fuel, gals Entrance 0.7 2.0 244 -39,630 70% -419 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace entrance windows 244 sqft $65 $15,860 Energy Costs Fuel Oil 1 - 25 -419 gal $2.40 ($32,094) Net Present Worth ($16,234) 0 Year Factor 100% Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 Airport-20: Replace Jetway Windows Energy Analysis Room R,old R,new Area, sqft kBTU η, boiler Fuel, gals Jetway 1.0 4.8 24 -3,322 70% -35 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace windows' 24 sqft $70 $1,680 Energy Costs Fuel Oil 1 - 25 -35 gal $2.40 ($2,690) Net Present Worth ($1,010) Airport-21: Replace Transformers Energy Analysis Use KW ηold ηnew kWh Jetway 30 94.6% 97.3% -7,096 -7,096 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace 30 KVA transformer 1 ea $7,500 $7,500 Energy Costs Electric Energy 1 - 25 -7,096 kWh $0.085 ($11,032) Electric Demand 1 - 25 -10 kW $3.90 ($693) Net Present Worth ($4,225) -9.72 Year 0 Factor 100% Year 0 -0.81 KW Airport-22: Variable Hold Room Air Flow Energy Analysis Option CFM ΔP η,fan η, motor kW Hours kWh Exist SF-1 -16,490 1.75 55% 91.7% -6.7 6,388 -42,896 VFD SF-1 16,490 1.75 55% 91.7% 6.7 1,278 8,579 VFD SF-1 13,740 1.50 55% 91.7% 4.8 5,110 24,509 Savings -9,808 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs SF-1 VFD 1 ea $6,800 $6,800 VAV terminal box 1 ea $1,000 $1,000 DDC integration 1 ea $4,000 $4,000 Annual Costs VFD maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 -9,808 kWh $0.085 ($15,248) Net Present Worth ($856) 0 0 BHP -8.3 0 5.9 Year 8.3 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Sitka Airport August 8, 2009 Airport-23: Convert to Variable Speed Hydronic Pumping Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh P-1 - - - - -1.3 8,760 -11,388 New P-1 w/VFD 40 16 64% 86.5% 0.2 8,760 1,910 Savings -9.7 -9,478 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install VFD 1 ea $4,500 $4,500 Convert hydronic heating system 1 ea $5,000 $5,000 DDC integration 1 ea $4,000 $4,000 Annual Costs VFD maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 -9,478 kWh $0.085 ($14,736) Electric Demand 1 - 25 -10 kW $3.90 ($695) Net Present Worth $661 Airport-24 : Replace Grundfos Pumps P-1 and P-4 Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh Exist P-1 - - - - -1.3 8,760 -11,388 Exist P-4 - - - - -0.64 8,760 -5,606 New P-1 80 36 64% 86.5% 1.0 8,760 8,594 NP4 90 7 44%70 0%04 8 760 3 379 Year 0 0 - 1.1 - BHP BHP - 0 0.3 04New P-4 90 7 44% 70.0% 0.4 8,760 3,379 Savings -7 -5,022 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace P-1 1 ea $2,500 $2,500 Replace P-4 1 ea $2,000 $2,000 Annual Costs Pump maintenance - Custom Pump 1 - 25 4 hr $60.00 $5,185 Energy Costs Electric Energy 1 - 25 -5,022 kWh $0.085 ($7,807) Electric Demand 1 - 25 -7 kW $3.90 ($491) Net Present Worth $1,386 Airport-25: Add Exhaust Air Heat Recovery Energy Analysis CFM T, ra T, ave osa hrs/day kBTU η, boiler Fuel, gals 1,400 70 41 19.5 -158,934 70% -1,682 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Fuel Oil 1 - 25 -1,682 gal $2.40 ($128,712) Net Present Worth ($128,712) η, heat recovery 50% Year Year 0 0 0.4 Alaska Energy Engineering LLC CBS Energy Audit 31 Centennial Building Section 3 Centennial Building INTRODUCTION The Centennial Building contains an auditorium, meeting and conference rooms, and a museum. Events are typically scheduled during the day with a few evening events. Fuel oil is consumed by the boiler for heat and domestic hot water and electricity supplies the kitchen domestic hot water and all other loads. The building characteristics are: • Size: 21,600 square feet • Occupied Hours: Variable hours, typical 8:00 am to 6:00 pm plus evening events • Occupancy: Highly variable with auditorium use, conference schedules, and higher occupancy during tourist season • HVAC Hours: Variable, typical schedule is Sunday-Friday 6:00 am to 6:00 pm; Saturday 6:00 am to 11:00 pm • Heating System: Fuel oil boiler and hydronic heating system with constant speed pumps • Ventilation Systems: Auditorium with central air handling units with constant airflow. Conference rooms with fan coil units and ventilation air supplied by unit ventilators. • Domestic Hot Water System: Indirect hot water maker heated by boiler. Kitchen hot water supplied by electric hot water heater. ENERGY CONSUMPTION AND COST The building energy sources are electricity and fuel oil. The following table summarizes the energy consumption and cost. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Fuel Oil 7,800 gals $18,700 1,100 (38%) Electricity 240,000 kWh $24,000 1,800 (62%) Totals - $42,700 2,900 (100%) 1. Consumption is the average from 2005-2008. Costs are based on 2009 prices. Trends Fuel Oil: Consumption increased steadily from 2003 to 2008. The increase is likely due to colder weather and greater use of the building. Electricity: Electricity use varies month-to-month with occupancy. On a yearly basis, electrical consumption and demand has been steady. Effective cost—energy plus demand charges—is 10.0¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 8.5¢ per kWh. Alaska Energy Engineering LLC CBS Energy Audit 32 Centennial Building The building is atypical in that it uses more electrical energy than heating energy. Most buildings in Alaska have an approximate ratio of heating loads to non-heating loads of 2:1; this building has a ratio of 1:2. The likely reason is that the chiller operates year-round to cool meeting rooms. Monitoring the chiller to determine its energy consumption will provide verification of the energy use. Energy consumption data is located at the end of this section. DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Original Gyp. Bd; 2x4 wd studs; R-11 batt; sheathing; stone R-10 1998 Expansion Gyp. Bd; 2x6 wd studs; R-19 batt; sheathing; cedar siding R-18 Roof Structure; 4” batt; ¾” plywood; ave. 6” rigid; built-up roofing R-50 Floor Slab Concrete slab-on-grade R-2 Perimeter Original Concrete footing; 1” rigid R-5 1988 Expansion Concrete footing; 2” rigid R-10 Windows Auditorium Wood frame; double pane R-2.0 Main Hall Metal frame w/o thermal break; double pane R-1.5 Meeting Rms Metal frame w/o thermal break; double pane R-1.5 1998 Expansion Metal frame w/o thermal break; double pane R-1.5 Doors Main Entrance Solid core double wood doors R-3.0 Corridor Solid core double wood doors R-3.0 Analysis Walls: The wall insulation is below optimal levels of R-25 to R-30. Adding insulation to existing walls does not provide a life cycle savings due to the high cost of replacing interior or exterior surfaces. If the cladding is replaced, the investment in additional insulation will provide a life cycle energy savings. Roof: The roof insulation is in the optimal insulation range of R-50 to R-60. Floor Slab: The lack of floor slab insulation is typical of past practice and there is no economical way to add insulation to the floor slabs. Perimeter: The 1” to 2” thick perimeter insulation is typical of past practice and there is no economical way to add insulation to the perimeter. For new construction, today’s higher energy prices offer incentive to invest in thicker perimeter insulation. Windows: None of the windows is optimally insulated. Typically, replacing double pane windows does not offer a life cycle savings. Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken frames. Good weather-stripping that minimizes infiltration is essential to thermal performance. Alaska Energy Engineering LLC CBS Energy Audit 33 Centennial Building Doors: The solid core wood doors are reasonably well insulated. The doors are important to the building architecture and there is little incentive to upgrade them. Good weather-stripping that minimizes infiltration is essential to thermal performance. Other items: • The main entrance is an arctic entrance with a set of inner and outer doors. The inner doors are held open, negating the ability of the entrance to minimize infiltration. • The chimney roof penetration in the West Fan Room is not sealed. • An exhaust duct penetration in the West Fan Room is not sealed. • A boiler room combustion air duct in the West Fan Room is not sealed. Heating System Description The heating system consists of two oil-fired, hot water boilers and a hydronic distribution system. The hydronic heating system has a primary/secondary configuration where a primary pump circulates water through the boiler and secondary pumps distribute the water to the heating units. The primary and secondary pumps are constant speed pumps that have constant energy use without regard to the heating load. The heating units consist of heating coils in the ventilation systems and fan coil units, convectors, and cabinet unit heaters. The hydronic heating system is also connected to two indirect hot water heaters that supplies domestic hot water to the west half of the building. The heating system has the following pumps: • Secondary Pump P-1: Convectors and cabinet unit heaters • Secondary Pump P-2: Indirect hot water maker HWM-1 • Secondary Pump P-4: UV-1 heating coil • Secondary Pump P-5: East heating units • Secondary Pump P-6: UV-3 heating coil • Secondary Pump P-7: Indirect hot water maker HWM-2 • Secondary Pump P-8: West heating units • Primary Pump P-10: Boiler B-1 • Primary Pump P-11: Boiler B-2 Analysis The boilers are operated in a lead/standby configuration year-round to supply year-round heating loads that are the result of Sitka’s temperate climate. Their operating thermostats have an on-off temperature differential of 20°F. A larger differential will decrease cycling losses and improve seasonal efficiency. The boilers do not have flue dampers to minimize the flow of heated air through the boiler and up the chimney when it is not operating. The pumps are manufactured by Grundfos. They are not as energy efficient as custom pumps with premium efficiency motors. Pump P-4 and P-6 are not interlocked to turn off with UV-1 and UV-3, respectively. Alaska Energy Engineering LLC CBS Energy Audit 34 Centennial Building Converting the secondary system to variable speed pumping will decrease pumping costs by allowing pump energy consumption to vary with the heating load. None of the unit heaters has an automatic valve to shut off the heating water flow when heat is not required. Ventilation System Description Unit Ventilator UV-1 and Return Fan RF-1: UV-1 is an air handling unit that supplies constant flow mixed air to the ceiling spaces where the west fan coil units FCU-1 to FCU-13 serve the rooms. The unit has a mixing box, filter section, heating coil, and supply fan. RF-1 draws return air from the rooms. Unit Ventilator UV-2 and Return Fan RF-2: UV-2 is an air handling unit that supplies constant flow mixed air to the ceiling space where the east fan coil units FCU-14 to FCU-25 serving the conference rooms. The unit has a mixing box, filter section, heating coil, and supply fan. Return fan RF-2 draws return air from the rooms. Unit Ventilator UV-3 and Return Fan RF-3: UV-3 is an air handling unit that supplies constant flow mixed air to the auditorium. The unit has a mixing box, filter section, heating coil, cooling coil, and supply fan. Return fan RF-3 draws return air from the auditorium. Unit Ventilator UV-4 and Return Fan RF-4: UV-4 is an air handling unit that supplies constant flow mixed air to the auditorium. The unit has a mixing box, filter section, heating coil, cooling coil, and supply fan. Return fan RF-3 draws return air from the auditorium. Exhaust Fan EF-1: EF-1 is a roof exhaust fan that draws exhaust air from the men’s toilet. Exhaust Fan EF-2: EF-2 is a roof exhaust fan that draws exhaust air from the women’s toilet. Fan Coil Units FCU-1 to FCU-25: The FCUs condition ceiling plenum air—consisting of ventilation air from UV-1 or UV-2 and return air from the rooms—and supply it to the respective room. The units consist of a filter section, heating coil, and cooling coil. Analysis UV-1/RF-1 and UV-2/RF-2: • Optimally these systems would be variable volume airflow system that modulates ventilation airflow with occupancy. During the majority of the time when occupancy is light and outside temperatures are moderate, the fan would operate at lower flow rates, saving fan and heating energy. • The fan coil units are not configured for airside natural cooling because the outside air from UV-1 and UV-2 is not ducted to each unit. In addition, UV-1 and UV-2 serve several FCUs. If the supply air temperature is reduced to cool one highly occupied room, the air to the FCUs will need to be reheated, at a considerable energy penalty. Airside natural cooling opportunity can be increased by: 1) providing each FCU an outside air duct that is modulated with occupancy and cooling requirements, or 2) connecting the supply air from UV-1 and UV-2 to each FCU and using controls to optimize the supply air temperature. Alaska Energy Engineering LLC CBS Energy Audit 35 Centennial Building UV-3/RF-3 and UV-4/RF-4: • Optimally these systems would be variable volume airflow systems that modulate airflow with cooling loads. During the majority of the time when occupancy is light and outside temperatures are moderate, the fan would operate at lower flow rates, saving fan and heating energy. • Ceiling fans in the auditorium can be added to move heated air downward, reducing roof heat loss. Fan Coil Units: Optimally, the fan coil units would modulate the ventilation airflow with occupancy. This will require that the ventilation air from UV-1 and UV-2 be ducted to each FCU, rather than be supplied to the ceiling plenum. Cooling System Description An air-cooled water chiller supplies chilled water to cooling coils in UV-3, UV-4, and the fan coil units. Cooling pumps P-9A and P-9B circulate cooling water to the cooling coils. Analysis The cooling system serves 27 separate fan systems. If any require cooling, the system operates. It is common for one or two FCUs to require cooling even on cool days due to their lack of airside natural cooling capability—which causes the cooling system to operate. Natural cooling requires significantly less energy than mechanical cooling. Airside natural cooling is typically the least expensive cooling system. The FCUs must be reconfigured to optimize their airside natural cooling potential. Airside natural cooling is limited when outside temperatures are warm so the cooling system will still be required. Another option is to optimize waterside natural cooling and minimize the need for mechanical cooling. Seawater, ground water, and the municipal water system are natural cooling options. Domestic Hot Water System Description Two indirect hot water heaters supply the building fixtures. An electric hot water heater supplies the kitchen. Domestic hot water recirculating pump P-3 maintains hot water in the distribution piping. The lavatory faucet aerators have a flow rate of 2.5 gpm. Analysis One of the indirect heaters may be able to supply the HW load. Turning off the second will reduce standby heat loss. Ultra-low aerators of 0.5 gpm are available for the lavatory faucets. Auto-sensing faucets reduce the water flow time three seconds during each use. Automatic Control System Description The building HVAC systems are controlled by a Honeywell DDC system that interfaces with the City’s community-wide system and by local controls. Alaska Energy Engineering LLC CBS Energy Audit 36 Centennial Building Basic Control Sequences Boilers B-1 and B-2: Operate in a lead/standby configuration. When a boiler is enabled, its operating thermostat turns the burner on at 155°F and off at 175°F. Secondary Pump P-1: Operates when outdoor temperature is less than 35°F. Off when outdoor temperature is greater than 72°F. Between 35°F and 72°F, operates when a connected load requires heat. Secondary Pump P-4: Operates when outdoor temperature is less than 35°F. Off when outdoor temperature is greater than 72°F. Between 35°F and 72°F, operates when a UV-1 requires heat. Secondary Pump P-5: Operates when outdoor temperature is less than 35°F. Off when outdoor temperature is greater than 72°F. Between 35°F and 72°F, operates when a connected load requires heat. Secondary Pump P-6: Operates when outdoor temperature is less than 35°F. Off when outdoor temperature is greater than 72°F. Between 35°F and 72°F, operates when UV-3 requires heat. Secondary Pump P-8: Operates when outdoor temperature is less than 35°F. Off when outdoor temperature is greater than 72°F. Between 35°F and 72°F, operates when a connected load requires heat. Primary Pump P-10: Operates when Boiler B-1 is enabled. Primary Pump P-11: Operates when Boiler B-2 is enabled. Unit Ventilator UV-1 and Return Fan RF-1: • Operate when any FCU is operating. • Mixing dampers modulate to supply a minimum of 25% outside air and to maintain 62°F mixed air temperature. • Heating coil automatic valve modulates to maintain a supply air temperature of 62°F. Unit Ventilator UV-2 and Return Fan RF-2: • Operate when any FCU is operating. • Mixing dampers modulate to supply a minimum of 25% outside air and to maintain 62°F mixed air temperature. • Heating coil automatic valve modulates to maintain a supply air temperature of 62°F. Unit Ventilator UV-3 and Return Fan RF-3: • Operate according to an occupied/unoccupied schedule. • Mixing dampers modulate to maintain a minimum of 25% outside air. • Heating coil automatic valve and cooling coil automatic valve modulate to maintain room temperature. Unit Ventilator UV-4 and Return Fan RF-4: • Operate according to an occupied/unoccupied schedule. • Mixing dampers modulate to maintain a minimum of 25% outside air. • Heating coil automatic valve and cooling coil automatic valve modulate to maintain room temperature. Alaska Energy Engineering LLC CBS Energy Audit 37 Centennial Building Exhaust Fan EF-1: Operate according to an occupied/unoccupied schedule. Exhaust Fan EF-2: Operate according to an occupied/unoccupied schedule. Fan Coil Units FCU-1 to FCU-25: • Each FCU fan operates according to a customized occupied/unoccupied schedule. • Heating coil automatic valve and cooling coil automatic valve modulate to maintain room temperature. Water Chiller: Internal controls operate the chiller whenever flow occurs to maintain 42°F supply temperature. Cooling Pumps P-9A and P-9B: Operates with P-9B as lead pump and P-9A as standby pump whenever a cooling load occurs. HWH-1 and HWM-2: • Pump P-2 operates to maintain the setpoint as sensed from an immersion thermostat. • Pump P-7 operates to maintain the setpoint as sensed from an immersion thermostat. Analysis Boilers B-1 and B-2: Expanding the operating differential to 25°-30°F will decrease cycling and improve seasonal efficiency. Secondary Pump P-4: Not interlocked with UV-1 Secondary Pump P-6: Not interlocked with UV-3 Unit Ventilator UV-1 and Return Fan RF-1: • The controls are not properly controlling the amount of ventilation air. On the day of the audit with 43°F outdoor temperature, it was supplying 60% outside air. • A demand controlled ventilation strategy that varies outside air with occupancy will reduce energy consumption. Unit Ventilator UV-2 and Return Fan RF-2: • The controls are not properly controlling the amount of ventilation air. On the day of the audit with 43°F outdoor temperature, it was supplying 30% outside air. • A demand controlled ventilation strategy that varies outside air with occupancy will reduce energy consumption. Unit Ventilator UV-3 and Return Fan RF-3: • A demand controlled ventilation strategy that varies outside air with occupancy will reduce energy consumption. Unit Ventilator UV-4 and Return Fan RF-4: • A demand controlled ventilation strategy that varies outside air with occupancy will reduce energy consumption. Water Chiller: The water chiller operates whenever a cooling load occurs. A storage tank would allow the chiller to operate when the tank needs to be recharged, improving efficiency. Alaska Energy Engineering LLC CBS Energy Audit 38 Centennial Building Lighting Description The interior lighting has been upgraded to energy efficient technologies in the recent past. The exterior canopy is lit by HPS lighting. Analysis Interior lighting was found to be on when rooms are unoccupied. Turning of the lighting saves energy and increases lamp life. The exterior canopy power density greatly exceeds the standards for high performance buildings. Electric Equipment Description The building has four computers that are left on continuously. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. Centennial-1: Close Auditorium Drapes Purpose: Heat will be saved if the auditorium drapes are closed when the room is not in use. This will reduce window heat loss. Scope: Close the auditorium drapes when the room is unoccupied. Analysis: This ECO is recommended without analysis. Centennial-2: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Lighting was left on in unoccupied rooms. Scope: Turning off lighting is an ECO with immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. This ECO requires behavioral changes where occupants regularly turn off lighting when a room is empty. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 39 Centennial Building Centennial-3: Reduce Entrance Temperatures Purpose: Heat will be saved by reducing the temperature setpoints of entrance heaters. The heaters are located near building entrances to dry the floor and minimize the thermal comfort impacts of cold air entering the building. The higher the temperature at the entrance the greater the amount of heat lost to outdoors, whether the doors are open or closed. Reducing the temperature setpoint to the minimum needed for thermal comfort and moisture control will reduce heat loss. Scope: Turn entrance setpoints down to 55°F and determine if this is adequate for thermal comfort and moisture control. Adjust as needed. Mark the desired setpoint on the thermostat so it can be visually verified. Analysis: This ECO is recommended without analysis. Centennial-4: Turn Off Redundant HW Heater Purpose: Heat will be saved if the redundant indirect HW heater is turned off. Scope: Turn off one of the indirect HW heaters in the West Fan Room. Analysis: It is likely that one of the heaters has sufficient capacity to meet the HW load. Turning off the second heater will reduce standby losses. This ECO is recommended without analysis. Centennial-5: Interlock Pumps Purpose: Electricity will be saved if the pumps serving the unit ventilator heating coils are interlocked to turn off with the unit. Scope: Revise the control sequence so the pumps serving the unit ventilator are enabled only when the unit is enabled. This ECO is recommended without analysis. Centennial-6: Seal Exhaust Duct Purpose: Heat will be saved if the exhaust duct to the louver in the West Fan Room is sealed. Scope: Seal the exhaust duct to the louver in the West Fan Room. Analysis: This ECO is recommended without analysis. Centennial-7: Replace Boiler Thermostat Purpose: Fuel oil will be saved if the boiler operating setpoints are replaced with a model that operates the boiler for a longer period during each cycle. The existing thermostat has a fixed 20°F differential between on and off setpoints. A new controller that allows a 30°F differential will increase the amount of time the boiler operates when it is turn on, which improves seasonal efficiency. Scope: The thermostat was replaced in July, 2009 with a model that has an adjustable temperature differential of 20-40°F. Set the differential as great as possible while supply sufficient heat. As a starting point, use typical differentials of 30°F in the winter and 40°F in the summer. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 40 Centennial Building Centennial-8: Seal Chimney Roof Penetration Purpose: Heat will be saved if the chimney roof penetration in the West Fan Room is sealed. The penetration is not sealed, allowing warm air to flow out the roof opening. Scope: Seal the chimney penetration through the West Fan Room roof. Analysis: This ECO is recommended without analysis. Centennial-9: Insulate Boiler Combustion Air Duct Purpose: Heat will be saved if the uninsulated combustion air duct in the West Fan Room is insulated. Scope: Insulate the combustion air duct in the West Fan Room. The duct is connected to the lower opening in the boiler room, which draws cold air in from outside. Analysis: This ECO is recommended without analysis. Centennial-10: Weather-strip Exterior Doors Purpose: Heat will be saved if doors are properly weather-stripped to reduce infiltration. The exterior corridor doors do not have adequate weather-stripping. Scope: Install or repair the weather-stripping on all exterior doors. Analysis: This ECO is recommended without analysis. High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. Centennial-11: Install Water-Conserving Aerators Purpose: Fuel oil will be saved by using water-conserving aerators on sinks and lavatories. Scope: Replace lavatory aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 150 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual fuel oil use by 190 gallons and energy costs by $460. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 $0 ($14,800) ($14,600) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 41 Centennial Building Centennial-12: Reduce Exterior Lighting Purpose: Electricity will be saved if 50% of the exterior lighting fixtures are turned off. Scope: Turn off 50% of the exterior lighting. The lighting is controlled by a photocell with two circuits for each lighting run. Every other fixture is on the same circuit. The lighting may be reduced by disconnecting one circuit. Analysis: The ASHRAE Energy Standard 90.1 has set a guideline of 1.25 watts per square foot for canopy lighting. The existing lighting has a power density of 2 watts per square. Turning off 50% of the fixtures will reduce the power density to 1 watt per square feet, which is more efficient than the guideline. This ECO will reduce annual electricity use by 9,700 kWh and energy costs by $820. It will also decrease lamp costs. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 ($3,700) ($15,100) ($18,600) Note: Negative numbers, in parenthesis, represent savings. Centennial-13: Install CUH Automatic Valves Purpose: Fuel oil will be saved if each unit heater has an automatic valve that shuts off the hydronic heating flow when heat is not needed. Currently, the heater coil is continuously hot which results in convective heat loss when the heater fan is not operating. While some of the heat loss may be useful, it is often not. Scope: Install an automatic valve on each unit heater to shut off the hydronic heating flow when heat is not needed. Analysis: This ECO will reduce annual fuel oil use by 60 gallons and energy costs by $133. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $800 $0 ($4,300) ($3,500) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 42 Centennial Building Centennial-14: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Analysis: The Centennial Building has four computers. The analysis assumes that the computers are not in use for 12 hours per day during the workweek and 16 hours per day on the weekend. The power settings were not checked on each machine, so the following analysis assumes that 25% of the computers are not set to enter sleep mode when inactive. Setting the power settings on 25% of the computers from screen saver to sleep mode will reduce annual electricity use by 600 kWh and energy costs by $50. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 400 kWh and energy costs by $30. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $200 $0 ($900) ($700) Turn Off $200 $0 ($600) ($400) Total $400 $0 ($1,500) ($1,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 43 Centennial Building Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. Centennial-15: Perform Meeting Room HVAC Optimization Analysis Purpose: Heat and electricity will be saved by optimizing the HVAC system serving the meeting rooms. Scope: Perform an optimization analysis of the meeting room HVAC systems. The current system has the following energy-related deficiencies: − Outside airflow does not modulate with occupancy. − Airside natural cooling is severely limited. − No waterside natural cooling − The chiller operates when any one cooling coil demands cooling. The scope of the optimization analysis should include: − Eliminate UV-1 and UV-2 and connect each FCU to a separate outside air duct. Use demand controlled ventilation to modulate outside air with occupancy. − Replace UV-1 and UV-2 with dedicated outdoor air systems DOAS-1 and DOAS-2 that supply tempered outside air to each FCU. Use demand controlled ventilation to modulate outside air with occupancy. Use supply air reset control to increase airside natural cooling. − Replace the chiller with waterside natural cooling using seawater, ground water, or potable water. Replacing the cooling coils with higher capacity coils that can cool with higher temperature water may be necessary to the feasibility of these options. − Add a fluid cooler to reduce chiller operating hours to the warmest days of the year. − Evaluate the benefits of a cooling storage tank in improving the efficiency of the waterside cooling system. − Nighttime pre-cooling of the building The estimate cost of the analysis is $7,500. Centennial-16: Replace HVAC Motors Purpose: Electricity will be saved if inefficient motors are upgraded to NEMA Premium® motors. Scope: Replace the motors in unit ventilators UV-1, UV-2, UV-3, and UV-4 with NEMA Premium® motors. Analysis: This ECO will reduce annual electricity use by 3,200 kWh, electric demand by 8 kW, and energy costs by $300. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $2,500 $0 ($5,600) ($3,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 44 Centennial Building Centennial-17: Install Boiler Room Heat Recovery Purpose: Heat will be saved if heat from the boiler room is recovered and transferred to the window wall of the auditorium. Scope: Install a heat recovery unit in the boiler room. Install ductwork to circulate boiler room air through one side of the heat recovery cell. Install ductwork to supply the heated air to the auditorium window wall and return it. Analysis: The analysis assumes that boiler jacket losses equal 2%. The HRU is assumed to recover 67% of this heat loss. This ECO will reduce annual fuel oil use by 600 gallons, increase electricity use by 6,000 kWh to operate the fans, with a net energy savings of $900. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $15,500 $2,600 ($36,000) ($17,900) Note: Negative numbers, in parenthesis, represent savings. Centennial-18: Install Boiler Flue Damper Purpose: Heat will be saved by installing a flue damper in the boiler chimney to minimize the airflow through the boiler and up the chimney. Scope: Install a damper in each boiler flue and control it to open prior to firing the boiler. Analysis: This ECO will improve the boiler seasonal efficiency by a minimum of 2% and reduce annual fuel oil use by 150 gallons and energy costs by $360. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,000 $1,300 ($11,300) ($4,000) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 45 Centennial Building Centennial-19: Retro-commission Building Purpose: Fuel and electricity will be saved if the building energy systems are optimized through a retro-commissioning process. The energy audit revealed that the building is over-ventilated, demand control ventilation is not being used, supply air reset controls are not in use, and there is opportunity to optimize the control strategies. Scope: Retro-commission the building with a focus on the following: − Optimize automatic control strategies − Reduce minimum outside air flow − Utilize demand controlled ventilation (CO2 sensors) − Utilize supply air reset control − Utilize occupancy sensor control Analysis: The analysis conservatively assumes that retro-commissioning will reduce fuel oil use by 6% and electricity use by 0.7% This ECO will reduce annual electricity use by 1,600 kWh, fuel oil use by 630 gallons and energy costs by $1,600.The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $31,700 $0 ($50,300) ($18,600) Note: Negative numbers, in parenthesis, represent savings. Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. Centennial-20: Replace UV-1/RF-1 and UV-2/RF-2 with DOAS Purpose: Heat will be saved if unit ventilators UV-1 and UV-2 are converted to dedicated outside air systems (DOAS). Scope: Replace VU-1/RF-1 and VU-2/RF-2 with a DOAS supplying 100% outside air to each fan-coil unit. Extend the supply ducts to each fan coil and modulate the flow of ventilation air to each fan coil with a carbon dioxide sensor. Analysis: This ECO will vary the amount of outside air by modulating the flow with occupancy. The analysis assumes that average ventilation flow will reduce from 2,075 cfm (25% OSA) to 750 cfm, which is sufficient for 50 people. This ECO will reduce annual electricity use by 8,100 kWh, electric demand by 21 kW, fuel oil use by 1,000 gallons, and energy costs by $3,200. The following table summarizes the life cycle cost analysis. When the unit ventilators and return fans require replacement—six of the eight have exceeded their expected service life—this ECO will offer a life cycle savings. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $95,500 $0 ($92,100) $3,400 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 46 Centennial Building Centennial-21: Install Auditorium Ceiling Fans Purpose: Heat will be saved by installing ceiling fans in the Auditorium to move warm air down to floor level. Scope: Install four ceiling fans in the Auditorium with variable speed controls. Analysis: The analysis assumes that the ceiling fans will keep the upper levels of the auditorium 10°F cooler, reducing heat loss through the roof. This ECO will reduce annual fuel oil use by 160 gallons but increase annual electricity use by 2,600 kWh, and demand by 0.3 kW. The result is a net annual energy savings of $150. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $9,000 $0 ($7,900) $1,100 Note: Negative numbers, in parenthesis, represent savings. Centennial-22: Replace Conference Room Windows Purpose: Heat will be saved by replacing the conference room windows with more energy efficient units. Scope: Replace the wood frame, double pane conference room windows with vinyl triple pane windows. Analysis: The existing windows have an insulation value of R-2. Replacement windows have an insulation value of R-4.8. This ECO will reduce annual fuel oil use by 370 gallons and energy costs by $890. However, the cost of replacing the windows is not offset by lower energy bills, so a life cycle savings does not occur. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $40,300 $0 ($28,400) $11,900 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 47 Centennial Building Centennial-23: Convert Auditorium to Variable Air Flow Purpose: Electricity will be saved if the auditorium ventilating units and return fans are converted from constant volume to variable volume. Scope: Install VFDs for UV-3, UU-4, RF-3, and RF-4 and controls for variable airflow operation. Analysis: A variable air volume system will only operate at full flow when it is warm outside or the room is densely occupied. Most of the time, the flow will be much lower. The analysis assumes that the airflow will average 50% of full flow. The analysis is based on auditorium use of 6 hours per day during the summer and 8 hours per day the rest of the year. This ECO will reduce annual electricity use by 11,000 kWh, electric demand by 24 kW, and energy costs by $1,000. The energy savings is insufficient to offset the cost of conversion to variable flow. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $19,000 $5,200 ($18,700) $5,500 Note: Negative numbers, in parenthesis, represent savings. Centennial-24: Variable Speed Heating Pumping Purpose: Electricity will be saved if the hydronic heating system is converted to variable flow pumping. Scope: Replace hydronic heating pumps P-1, P-5, and P-8 with two lead/standby variable speed pumps. Analysis: The analysis assumes that the average flow rate will be 33% of the peak flow rate. This ECO will reduce annual electricity use by 8,300 kWh, electric demand by 6 kW, and energy costs by $730. However, the high cost of converting the piping system and pumps to variable speed is not offset by the lower energy costs. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $17,500 $2,600 ($13,300) $6,800 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 48 Centennial Building Centennial-25: Replace Grundfos Pumps P-5, P-8, P-10, P-11 Purpose: Electricity will be saved if the Grundfos pumps are replaced with custom pumps with NEMA Premium® Motors. Scope: Replace pumps P-5, P-8, P-10 and P-11with custom pumps. Analysis: Grundfos pumps require minimal maintenance and are easily replaced. However, they are less energy efficient than custom pumps because they are not customized to the system operating condition. In addition, the integral motors on larger pumps are less efficient than NEMA Premium® motors. The result is that Grundfos pumps often have higher energy costs. This ECO will reduce annual electricity use by 7,900 kWh, electric demand by 11 kW, and energy costs by $720. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $9,000 $10,400 ($13,100) ($6,300) Note: Negative numbers, in parenthesis, represent savings. Centennial-26: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand is very steady so there is little need to educate people on demand control. Centennial-27: Close Inner Entrance Doors Purpose: Heat will be saved if the inner entrance doors are closed so that the entrances functions as an arctic entrance. Scope: Close the inner entrance doors during the lighter occupancy period of September 15 to May 15. Install an ADA door operator on one of the inner doors. Analysis: The cost of installing an ADA operator on the inner door ($10,000) exceeds the life cycle energy savings. This ECO is not recommended. Centennial-28: Increase Wall Insulation Purpose: Heat will be saved by adding insulation to the exterior walls. Analysis: The walls are constructed of 2x4 wood studs with cavity insulation. The assembly has an R-12 insulation level, which is below current optimal levels of R-25+. Previous analyses have shown that that adding insulation to the wall will not provide a life cycle savings because of the high cost of replacing the interior or exterior finishes. If the finishes are updated in the future, additional wall insulation is warranted. Alaska Energy Engineering LLC CBS Energy Audit 49 Centennial Building Centennial-29: Increase Perimeter Insulation Purpose: Electricity will be saved by adding perimeter insulation. Analysis: The concrete footings have 1” of rigid perimeter insulation. This is below the current optimal level of 3” thick insulation. Previous analyses have shown that that adding insulation to the perimeter footings will not provide a life cycle savings. Centennial-30: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 50 Centennial Building SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Fuel Oil Electricity Total Current Energy Costs $18,700 $24,000 $42,700 Behavioral and Operational Centennial-1: Close Auditorium Drapes Centennial-2: Turn Off Lighting Centennial-3: Reduce Entrance Temperatures Centennial-4: Turn Off Redundant HW Heater Centennial-5: Interlock Pumps Centennial-6: Seal Exhaust Duct Centennial-7: Replace Boiler Thermostat Centennial-8: Seal Chimney Roof Penetration Centennial-9: Insulate Boiler Combustion Air Duct Centennial-10: Weather-strip Exterior Doors Energy Savings (Estimated) ($660) ($70) ($730) High Priority Centennial-11: Install Water Conserving Aerators ($460) $0 ($460) Centennial-12: Reduce Exterior Lighting $0 ($820) ($820) Centennial-13: Install CUH Automatic Valves ($130) $0 ($130) Centennial-14a: Set Computers to Sleep Mode $0 ($50) ($50) Centennial-14b: Turn Off Inactive Computers $0 ($30) ($30) Medium Priority Centennial-15: Meeting Room Optimization Analysis n/a n/a n/a Centennial-16: Replace HVAC Motors $0 ($300) ($300) Centennial-17: Install Boiler Room Heat Recovery ($1,440) $550 ($890) Centennial-18: Install Boiler Flue Damper ($350) $0 ($350) Centennial-19: Retro-commission HVAC Systems ($1,500) ($140) ($1,640) ECO Savings ($4,540) ($860) ($5,400) (24%) (4%) (12%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 51 Centennial Building Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational Centennial-1: Close Auditorium Drapes $0 Centennial-2: Turn Off Lighting $0 Centennial-3: Reduce Entrance Temperatures $100 Centennial-4: Turn Off Redundant HW Heater $100 Centennial-5: Interlock Pumps $100 Centennial-6: Seal Exhaust Duct $200 Centennial-7: Replace Boiler Thermostat $400 Centennial-8: Seal Chimney Roof Penetration $400 Centennial-9: Insulate Boiler Combustion Air Duct $400 Centennial-10: Weather-strip Exterior Doors $1,200 Totals $2,900 $0 ($22,300) ($19,400) High Priority Centennial-11: Install Water Conserving Aerators $200 $0 ($14,800) ($14,600) Centennial-12: Reduce Exterior Lighting $200 ($3,700) ($15,100) ($18,600) Centennial-13: Install CUH Automatic Valves $800 $0 ($4,300) ($3,500) Centennial-14a: Set Computers to Sleep Mode $200 $0 ($900) ($700) Centennial-14b: Turn Off Inactive Computers $200 $0 ($600) ($400) Medium Priority Centennial-15: Meeting Room Optimization Analysis $7,500 n/a n/a $7,500 Centennial-16: Replace HVAC Motors $2,500 $0 ($5,600) ($3,100) Centennial-17: Install Boiler Room Heat Recovery $15,500 $2,600 ($36,000) ($17,900) Centennial-18: Install Boiler Flue Damper $6,000 $1,300 ($11,300) ($4,000) Centennial-19: Retro-commission HVAC Systems $31,700 $0 ($50,300) ($18,600) Totals $67,700 $200 ($161,200) ($93,300) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 52 Centennial Building ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic fuel oil consumption • Historic electricity use • Energy and life cycle cost analysis calculations 0 2,000 4,000 6,000 8,000 10,000 0 2,000 4,000 6,000 8,000 10,000 2003 2004 2005 2006 2007 2008 Degree DaysGallonsFuel Oil Consumption Gallons Degree Days Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 21,280 74 17,760 67 18,240 62 17,280 72 74,560 Feb 19,360 70 16,640 67 19,200 69 17,440 82 72,640 Mar 18,080 74 16,160 70 16,320 74 18,080 64 68,640 Apr 18,560 83 16,800 72 19,840 93 17,440 72 72,640 May 22,240 80 19,840 78 19,040 82 17,600 93 78,720 Jun 21,280 86 19,040 74 21,760 80 22,400 83 84,480 Jul 19,680 88 25,440 82 19,360 83 22,240 75 86,720 Aug 24,320 88 20,800 80 20,000 82 20,480 74 85,600 Sep 19,840 77 19,200 93 20,640 77 22,880 85 82,560 Oct 21,600 78 25,280 82 20,640 75 18,720 77 86,240 Nov 19,360 82 19,040 82 24,000 83 21,600 74 84,000 D 21 600 86 24 480 93 21 600 80 17 600 85 85 280 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 21,600 86 24,480 93 21,600 80 17,600 85 85,280 Total 247,200 240,480 240,640 233,760 240,520 Average 20,600 81 20,040 78 20,053 78 19,480 78 20,043 Load Factor 35.0% 35.1% 35.1% 34.3% 79 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 1,629 146 1,775 1,548 183 1,731 -2.5% Feb 1,711 171 1,882 1,561 221 1,782 -5.3% Mar 1,466 190 1,655 1,616 152 1,768 6.8% Apr 1,765 264 2,030 1,561 183 1,744 -14.0% May 1,697 221 1,918 1,575 264 1,839 -4.1% Jun 1,928 215 2,143 1,983 227 2,210 3.1% Jul 1,724 227 1,951 1,969 196 2,165 10.9% Aug 1,779 221 1,999 1,820 190 2,009 0.5% Sep 1,833 202 2,035 2,024 233 2,257 10.9% Oct 1,833 196 2,029 1,670 202 1,872 -7.7% Nov 2,119 227 2,346 1,915 190 2,104 -10.3% Dec 1,915 215 2,129 1,575 233 1,808 -15.1% Total $ 21,399 $ 2,493 $ 23,892 $ 20,814 $ 2,474 $ 23,288 -2.5% Average $ 1,783 $ 208 $ 1,991 $ 1,735 $ 206 $ 1,941 -2.5% Cost ($/kWh) 0.0993 89% 11% 0.0996 0.3% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 0 5,000 10,000 15,000 20,000 25,000 30,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 5,000 10,000 15,000 20,000 25,000 30,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 10 20 30 40 50 60 70 80 90 100 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 0 10 20 30 40 50 60 70 80 90 100 0 5,000 10,000 15,000 20,000 25,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Centennial-1 Close Auditorium Drapes 1 job $0 $0 Centennial-2 Turn Off Lighting 1 job $0 $0 Centennial-3 Reduce Entrance Temperatures 1 job $100 $100 Centennial-4 Turn Off Redundant HW Heater 1 job $100 $100 Centennial-5 Interlock Pumps 1 job $100 $100 Centennial-6 Seal Exhaust Duct 1 job $200 $200 Centennial-7 Replace Boiler Thermostat 1 job $400 $400 Centennial-8 Seal Chimney Roof Penetration 1 job $400 $400 Centennial-9 Insulate Boiler Combustion Air Duct 1 job $400 $400 Centennial-10 Weather-strip Exterior Doors 1 job $1,200 $1,200 Energy Costs Electric Energy 1 - 25 -800 kWh $0.085 ($1,244) Fuel Oil 1 - 25 -275 gal $2.40 ($21,046) Net Present Worth ($19,390) Centennial-11: Install Water Conserving Aerators Energy Analysis August 8, 2009 0 0 0 Year 0 0 0 0 0 0 0 Energy Analysis HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kBTU Boiler Effic Fuel, gals Indirect 2.5 0.5 15 -27,375 -18,265 70% -193 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 4 ea $50 $200 Energy Costs Fuel Oil 1 - 25 -193 gal $2.40 ($14,791) Net Present Worth ($14,591). 150 Use/Day Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 Centennial-12: Reduce Exterior Lighting Energy Analysis # Fixtures Watts Ballast kWh watts/sqft Existing 77 50 115% 19,392 2.0 50% Off 39 50 115% 9,822 1.0 watts/sqft sqft kW LEED 1.25 2,205 2.8 Lamp Cost Life, hrs Hour/year $15.00 24,000 4,380 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Turn off 50% of lighting 1 job $200 $200 Annual Costs Increased lamp life 1 - 25 -39 lamp-yr $4.38 ($3,690) Energy Costs Electric Energy 1 - 25 -9,696 kWh $0.085 ($15,075) Net Present Worth ($18,565) Centennial-13: Install CUH Automatic Valves Energy Analysis Loss, BTUH Number Factor Loss, kBTU Fuel, gals 1,500 2 20% -5,256 -56 2.2 $/yr 2.74 Boiler Effic 70% kWh 12,072 Year 0 kW 4.4 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install AV and controls 2 ea $400 $800 Energy Costs Fuel Oil 1 - 25 -56 gal $2.40 ($4,257) Net Present Worth ($3,457) Centennial-14a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 4 -125 12 16 -2,392 25% -598 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Change power settings 1 job $200 $200 Energy Costs Electric Energy 1 - 25 -598 kWh $0.085 ($930) Net Present Worth ($730) kW -0.5 Year Year 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 Centennial-14b: Turn Off Inactive Computers Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 4 -20 12 16 -383 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Change power settings 1 job $200 $200 Energy Costs Electric Energy 1 - 25 -383 kWh $0.085 ($595) Net Present Worth ($395) Centennial-15: Perform Meeting Room Optimization Analysis Cost Estimate Qty Unit Base Cost Year 0 Cost Conceptualize Options Site visit 16 hrs $98 $1,568 Conceptual design 8 hrs $98 $784 Energy Analysis Computer model 24 hrs $98 $2,352 Life Cycle Cost analysis Economic and energy criteria 2 hrs $98 $196 Construction costs 8 hrs $98 $784 Maintenance costs 3 hrs $98 $294 Energy costs 4 hrs $98 $392 Report: Draft, comments, final 12 hrs $98 $1,176 $7 500 Year 0 0 kW -0.1 Year 0 0 0 0 0 0 0 $7,500 Centennial-16: Replace HVAC Motors Energy Analysis Unit HP η, old η, new Hours ΔkWh UV-1 1 77% 85.5% 4,628 -446 UV-2 1 77% 85.5% 4,628 -446 UV-3 3 81.4% 89.5% 4,628 -1,152 UV-4 3 81.4% 89.5% 4,628 -1,152 -3,195 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace 1 HP motor 2 ea $570 $1,140 Replace 3 HP motor 2 ea $670 $1,340 Energy Costs Electric Energy 1 - 25 -3,195 kWh $0.085 ($4,967) Electric Demand 1 - 25 -8 kW $3.90 ($591) Net Present Worth ($3,078) ΔkW -0.10 -0.10 Year 0 0 -0.25 -0.25 -8 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 Centennial-17: Install Boiler Room Heat Recovery Energy Analysis Boiler MBH Factor Loss, MBH Factor kBTU Boiler Effic Fuel, gals CFM 810 2% 16 40% -56,765 70% -601 736 HP η, motor kW Hours 0.8 81.0% 0.7 8,760 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs 750 CFM heat recovery unit 1 ea $7,500 $7,500 Supply and return ductwork 1 ea $5,000 $5,000 Electric and controls 1 ea $3,000 $3,000 Annual Costs HRV maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 6,051 kWh $0.085 $9,408 Electric Demand 1 - 25 8 kW $3.90 $591 Fuel Oil 1 - 25 -601 gal $2.40 ($45,971) Net Present Worth ($17,880) Centennial-18: Install Boiler Flue Damper Energy Analysis Input, gph FO Gallons On Hours Off Hours CFM w/damper kBTU Boiler Effic Fuel, gals 5.8 7,500 1,293 7,467 5 -13,963 70% -148 6,051 Year 0 0 0 CFM w/o damper 15 Recovery, MBH -6 kWh Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install flue damper 2 ea $3,000 $6,000 Annual Costs Flue damper maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Fuel Oil 1 - 25 -148 gal $2.40 ($11,308) Net Present Worth ($4,012) Centennial-19: Retro-commission HVAC Systems Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Develop control sequences 1 ea $3,000 $3,000 Automatic control modifications 4 pts $1,500 $6,000 Retro-commissioning Modify control drawings 36 hrs $140 $5,040 Modify control software 24 hrs $140 $3,360 On-site Implementation and travel, including commissioning 40 hrs $140 $5,600 Perdiem and Travel 1 ea $2,500 $2,500 Closeout 16 hrs $140 $2,240 Verification 1 ea $4,000 $4,000 Energy Costs Electric Energy 1 - 25 -1,600 kWh $0.085 ($2,488) Fuel Oil 1 - 25 -625 gal $2.40 ($47,831) Net Present Worth ($18,579) 0 0 0 0 0 0 Year 0 Year 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 Centennial-20: Replace UV-1 and UV-2 with DOAS Energy Analysis Ventilation Heat Option CFM,sa % OSA Tma kBTU Boiler Effic Fuel, gals Exist UV-1/2 8,300 24% 63 -264,677 70% -2,801 DOAS-1/2 1,200 100% 41 168,302 70% 1,781 -1,020 Fan Energy Unit HP η, motor kW kWh UV-1/RF-1 -1.75 85.5% -1.53 -7,066 UV-2/RF-2 -1.75 85.5% -1.53 -7,066 DOAS-1 0.75 85.5% 0.65 3,028 DOAS-2 0.75 85.5% 0.65 3,028 -20.9 -8,076 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace UV-1/RF-1 with DOAS-1 1 ea $9,000 $9,000 Replace UV-2/RF-2 with DOAS-2 1 ea $9,000 $9,000 Extend ductwork to fan coils with auto damper 25 ea $1,000 $25,000 CO2 sensors and controls 35 pts $1,500 $52,500 Energy Costs Electric Energy 1 - 25 -8,076 kWh $0.085 ($12,556) Electric Demand 1 - 25 -20.9 kW $3.90 ($1,494) Fuel Oil 1 - 25 -1,020 gal $2.40 ($78,049) Net Present Worth $3 401 4,628 4,628 70 70 4,628 4,628 Year 0 0 0 0 Tsa Hours Net Present Worth $3,401 Centennial-21: Install Auditorium Ceiling Fans Energy Analysis Option Area Roof R-value Tosa kBTU Boiler Effic Fuel, gals Exist -6,050 35 41 -51,484 70% -545 Fans 6,050 35 41 36,341 70% 385 Savings -160 Number watts kW Hours 4 75 0.3 8,760 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install ceiling fans 6 ea $1,000 $6,000 Electrical 6 ea $500 $3,000 Energy Costs Electric Energy 1 - 25 2,628 kWh $0.085 $4,086 Electric Demand 1 - 25 4 kW $3.90 $257 Fuel Oil 1 - 25 -160 gal $2.40 ($12,263) Net Present Worth $1,080 Year 0 65 Trm 75 2,628 0 kWh Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 Centennial-22: Replace Conference Room Windows Energy Analysis Option Area R-value Tosa kBTU Boiler Effic Fuel, gals Existing -576 2.0 41 -60,549 70% -641 New 576 4.8 41 25,441 70% 269 Savings -372 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace windows 576 sqft $70 $40,320 Energy Costs Fuel Oil 1 - 25 -372 gal $2.40 ($28,432) Net Present Worth $11,888 Centennial-23: Convert Auditorium to Variable Flow Energy Analysis Option CFM ΔP η, fan η, motor kW Hours kWh Exist UV-3/4 -13,000 1.5 55% 89.5% -4.6 2,738 -12,728 Exist RF-3/4 -10,000 0.50 55% 81.0% -1.3 2,738 -3,606 VFD UV-3/4 6,500 1.0 55% 89.5% 1.5 2,738 4,243 VFD RF-3/4 5,000 0.33 55% 81.0% 0.4 2,738 1,190 Savings -24 -10,901 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs VU3/4VFD 3HP i i 2 $5 000 $10 000 Year 0 HP -5.6 0.5 65 65 Year 0 Trm 1.9 -1.4 VU-3/4 VFD, 3 HP + integration 2 ea $5,000 $10,000 RF-3/4 VFD, 3/4 HP + integration 2 ea $4,500 $9,000 Annual Costs VFD maintenance 1 - 25 4 hr $60.00 $5,185 Energy Costs Electric Energy 1 - 25 -10,901 kWh $0.085 ($16,949) Electric Demand 1 - 25 -23.9 kW $3.90 ($1,704) Net Present Worth $5,532 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Centennial Building August 8, 2009 Centennial-24: Convert to Variable Speed Hydronic Pumping Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh New P-5 -70 35 63% 86.5% -0.8 8,760 -7,427 New P-8 -20 25 50% 70.0% -0.3 8,760 -2,360 P-1 -20 9 35% 65.0% -0.1 8,760 -1,307 New Pumps w/VF 45 22 68% 86.5% 0.3 8,760 2,780 Savings -5.7 -8,313 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Demo pumps and piping 1 ea $2,000 $2,000 New lead/standby pumps w/VFD 2 ea $4,500 $9,000 Piping 1 ea $2,500 $2,500 DDC integration 1 ea $4,000 $4,000 Annual Costs VFD maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 -8,313 kWh $0.085 ($12,925) Electric Demand 1 - 25 -6 kW $3.90 ($406) Net Present Worth $6,761 Centennial-25: Replace Grundfos Pumps P-5, P-8, P-10, P-11 Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh Ei P5 13 8 760 11 388 -0.13 Year -0.3 0 0 0 0 BHP -1.0 0.4 BHP Exist P-5 - - - - -1.3 8,760 -11,388 Exist P-8 - - - - -0.7 8,760 -6,132 Exist P-10 - - - - -0.57 8,760 -4,993 Exist P-11 - - - - -0.57 8,760 -4,993 New P-5 70 35 63% 86.5% 0.8 8,760 7,427 New P-8 20 25 50% 70.0% 0.3 8,760 2,360 New P-10 85 20 67% 85.5% 0.56 8,760 4,902 New P-11 85 20 67% 85.5% 0.56 8,760 4,902 Savings -11 -7,915 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace P-5 and P-8 2 ea $2,500 $5,000 Replace P-10 and P-11 2 ea $2,000 $4,000 Annual Costs Pump maintenance - Custom Pump 1 - 25 8 hr $60.00 $10,369 Energy Costs Electric Energy 1 - 25 -7,915 kWh $0.085 ($12,306) Electric Demand 1 - 25 -11 kW $3.90 ($773) Net Present Worth $6,290 - - 1.0 0.6 Year 0 0 - - 0.3 0.6 This page intentionally left blank Alaska Energy Engineering LLC CBS Energy Audit 53 City Hall Section 4 City Hall INTRODUCTION City Hall contains office and support spaces for city government. The building uses electricity for space heating, domestic hot water, all other loads. The building characteristics are: • Size: 17,160 square feet • Occupied Hours: Monday to Friday office schedule with minor night and weekend use. • Occupancy: City staff of ~45 people plus community visitors. Daily occupancy follows a similar pattern: people start to arrive at 7:00 am, most are to work by 8:00 am, many leave for lunch from 12:00 to 1:00 pm, and people leave from 4:00 to 6:00 pm. • HVAC Hours: Monday-Friday 7:00 am to 6:30 pm • Heating and Ventilating System: Central air handling unit with variable airflow. Reheat coils in air system supply interior zones. Exterior zones are heated by electric baseboard heaters and portable electric heaters. • Domestic Hot Water System: Electric hot water heater. ENERGY CONSUMPTION AND COST City Hall is an all-electric building. The following table summarizes the energy consumption and cost. Electricity use spreadsheets and graphs are at the end of this section. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Electricity 380,000 kWh $36,000 1,300 1. Consumption is the average from 2005-2008. Costs are based on 2009 prices. Trends Electricity: The use pattern is typical of an electrically heated building. Consumption and demand are much higher during the heating months and taper gradually to baseline loads during the summer. On a yearly basis, consumption has increased slightly each year due to more people in the building and greater use of electric heaters due to poor HVAC controls. Effective cost—energy plus demand charges—is 9.3¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 8.5¢ per kWh. Energy consumption data is located at the end of this section. Alaska Energy Engineering LLC CBS Energy Audit 54 City Hall DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Original Conc. Gyp. Bd; 1-1/2” furring with batt; concrete wall, 2” EIFS R-15 Original Stud Gyp. Bd; 2x6 metal studs; R-19 batt; 2” EIFS R-17 1994 Renovation Gyp. Bd; 2x6 wd studs; R-19 batt; 2” EIFS R-18 Roof Structure; 4” EPS + ave 7” taper; built-up roofing R-45 Floor Slab Concrete slab-on-grade R-2 Perimeter Original Concrete footing R-1 Windows 1st and 2nd floors Wood frame; double pane; good weather-stripping R-1.5 3rd Floor Wood frame; double pane; good weather-stripping R-1.75 Doors Metal frame w/o thermal break; single pane glazing; poor weather-stripping R-0.5 Analysis Walls: The wall insulation is below optimal levels of R-25-30. Adding insulation to existing walls does not provide a life cycle savings due to the high cost of replacing interior or exterior surfaces. When the EIFS is replaced, an investment in additional insulation will provide a life cycle energy savings. Roof: The roof insulation is below optimal insulation levels of R-50 to R-60. Adding insulation will not provide a life cycle savings due to the high cost of replacing the built-up roofing. When the roofing is replaced in the future, additional insulation will provide a life cycle savings. Floor Slab: The lack of floor slab insulation is typical of past practice and there is no economical way to add insulation to the floor slabs. Perimeter: The lack of perimeter insulation creates a cool slab, which can cause condensation and mold problems. There is no economical way to add insulation to the perimeter. Windows: None of the windows is optimally insulated. Typically, replacing double pane windows does not offer a life cycle savings. Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken frames. Good weather-stripping that minimizes infiltration is essential to thermal performance. Doors: The solid core wood doors are reasonably well insulated. The doors are important to the building architecture and there is little incentive to upgrade them. Good weather-stripping that minimizes infiltration is essential to thermal performance. Alaska Energy Engineering LLC CBS Energy Audit 55 City Hall Heating System Description The building perimeter is heated by baseboard electric heaters. Interior zones are heated by electric heating coils in the supply ductwork. Analysis Numerous rooms have additional plug-in heaters due to poor thermal comfort during cold weather. Ventilation System Description Air handling unit AHU-1 supplies ventilation and natural cooling to the rooms. AHU-1 is a variable airflow system consisting of a mixing box, filter section, and supply fan. A pressure sensor in the supply ductwork controls variable flow inlet vanes on the fan inlet. Each zone has a variable air volume (VAV) terminal box that modulates the flow of air to the space. VAV boxes serving interior zones have electric heating coils. Relief air flows out relief hoods on the roof. Exhaust Fan EF-1: EF-1 is a roof exhaust fan that draws exhaust air from the toilets and janitor’s closet. Analysis AHU-1: • The interior duct lining in the discharge plenum is loose. • Supply ductwork in the crawlspace and on the roof is under insulated. EF-1: There is no heat recovery on the exhaust air. Cooling System Description The computer room has a cooling unit due to the high heat gain in the room. The cooling unit is a portable unit with heated air exhausted to the ceiling plenum. Analysis The room can be adequately cooled with a natural cooling system using outside air for the majority of the year. Domestic Hot Water System Description An electric HW heater supplies domestic hot water to the building. The heater has a 6 kW heater element. The lavatory faucet aerators have a flow rate of 2.5 gpm. The faucets are not auto-sensing. Alaska Energy Engineering LLC CBS Energy Audit 56 City Hall Analysis A hot water heater with two 3 kW stages will incur smaller demand charges because one stage is likely to keep up with water demand most of the time. Ultra-low aerators of 0.5 gpm are available for lavatory faucets. Auto-sensing faucets reduce the water flow time three seconds during each use. Automatic Control System Description The building HVAC systems are controlled by a Barber Coleman Network 8000 DDC system and by local controls. The system is past its service life and does not interface with the City’s community- wide Honeywell system. Basic Control Sequences Air Handling Unit AHU-1: • AHU-1 operates in accordance with an occupied/unoccupied schedule. • Mixing dampers modulate to maintain the supply air setpoint. Exhaust Fan EF-1: Interlocked to operate when AHU-1 operates. Temperature Control: Room thermostat modulates the airflow and controls the applicable baseboard heater or VAV heating coil to maintain the setpoint. On a call for heat, modulates the VAV box to minimum airflow and operates the heating coil. On a call for cooling, the airflow increases to provide cooling. Electric HW heater: Immersion thermostat operates the heating elements to maintain setpoint. Analysis The following DDC controls are not operating properly: • The AHU-1 mixed air control is bringing in 37% outside air, which is more than the code requirements. • The AHU-1 mixing dampers do not close when the fan is off. • The AHU-1 variable volume inlet vanes do not modulate with duct pressure. • The room thermostats are not properly modulating the airflow and controlling the electric heaters. Most rooms have additional plug-in heaters due to a lack of thermal comfort. Lighting Description The interior lighting has been upgraded to energy efficient technologies in the recent past. There are no occupancy sensors to control lighting. Analysis Interior lighting was found to be on when rooms are unoccupied. Turning of the lighting saves energy and increases lamp life. Alaska Energy Engineering LLC CBS Energy Audit 57 City Hall Electric Equipment Description The building has 42 office computers and 8 network servers that are left on continuously. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. City Hall-1: Turn Off Heaters Purpose: Electricity costs will be reduced if electric heaters are turned off during the night and weekends. Analysis: Building occupants should turn off their electric heaters when they leave the building so they do not keep the rooms warm when they are unoccupied. Analysis: This ECO is recommended without analysis. City Hall-2: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Lighting was left on in unoccupied rooms. Scope: Turning off lighting is an ECO with immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. This ECO requires behavior changes where occupants regularly turn off lighting rather than leave it on. Analysis: This ECO is recommended without analysis. City Hall-3: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment is an ECO with immediate payback. This ECO requires behavior changes where occupants regularly turn off equipment when they are finished with it. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 58 City Hall City Hall-4: Weather-Strip Exterior Doors Purpose: Heat will be saved if exterior doors are properly weather-stripped to reduce infiltration. The exterior doors do not have adequate weather-stripping. Scope: Install or repair the weather-stripping on all exterior doors. Analysis: This ECO is recommended without analysis. High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. City Hall-5: Install Water-Conserving Aerators Purpose: Electricity will be saved by using water-conserving aerators on sinks and lavatories. Scope: Replace lavatory aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 75 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual electric use by 4,300 kWh and energy costs by $360. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 $0 ($6,700) ($6,500) Note: Negative numbers, in parenthesis, represent savings. City Hall-6: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Alaska Energy Engineering LLC CBS Energy Audit 59 City Hall Analysis: City Hall has 42 computers plus 8 network servers. The analysis assumes that the computers are in use for 9 hours per day during the workweek. The power settings were not checked on each machine, so the following analysis assumes that 25% of the computers are not set to enter sleep mode when inactive. Setting the power settings on 25% of the computers from screen saver to sleep mode will reduce annual electricity use by 8,400 kWh and energy costs by $710. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 5,400 kWh and energy costs by $460. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $500 $0 ($13,100) ($12,600) Turn Off $500 $0 ($8,400) ($7,900) Total $1,000 $0 ($21,500) ($20,500) Note: Negative numbers, in parenthesis, represent savings. Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. City Hall-7: Install VFD on AHU-1 Purpose: The inlet vanes on AHU-1 are less efficient than a VFD in varying airflow. Scope: Replace the AHU-1 inlet vanes with a VFD. Analysis: This ECO will annually save 15,000 kWh of electricity and $1,300 in energy costs. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $7,300 $4,300 ($23,400) ($11,800) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 60 City Hall City Hall-8: Install HW Heater Demand Controls Purpose: Demand charges will be reduced by installing controls to limit electric demand of the domestic hot water heater. Scope: Install two additional immersion thermostats. Rewire so each thermostat controls a 2 kW element. Configure setpoints to limit demand. Analysis: The analysis assumes that a 2 kW recovery is sufficient 6 months, 4 kW is sufficient for 4 months, and 6 kW is needed for 2 months each year. This ECO will reduce annual electric demand by 32 kW and energy costs by $130. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $1,500 $0 ($2,300) ($800) Note: Negative numbers, in parenthesis, represent savings. City Hall-9: Install Computer Room Natural Cooling System Purpose: Electricity will be saved if the computer room is naturally cooled with outside air instead of mechanically cooling. Scope: Install a natural cooling air handling unit with mixing box to cool the computer room. The cooling air will be discharged to the building ceiling return plenum as preheated ventilation air, thus reducing the amount of ventilation air drawn in by AHU-1. Analysis: This ECO will reduce annual electricity use by 3,200 kWh, electric demand by 14 kW and energy costs by $330. The following table summarizes the analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $7,500 ($3,900) ($6,000) ($2,400) Note: Negative numbers, in parenthesis, represent savings. City Hall-10: Lighting Occupancy Sensor Control Purpose: Electricity use will be reduced by installing occupancy sensors to turn off lighting in unoccupied rooms. Scope: Install occupancy sensors for lighting control in the offices and toilet rooms. Analysis: The analysis assumes that office and toilet room lighting will, on an average, be off three and six hours per day, respectively. This ECO will reduce annual electricity use by 10,000 kWh and energy costs by $850. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $12,000 $1,300 ($15,500) ($2,200) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 61 City Hall City Hall-11: Replace Entrance Doors Purpose: Heat will be saved if the entrance doors with single pane glazing and no thermal breaks are replaced with energy efficient doors. Scope: Replace the entrance doors with thermal broken doors with insulating glazing. Analysis: This ECO will reduce annual electricity use by 6,700 kWh and energy costs by $570. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $10,000 $0 ($10,400) ($400) Note: Negative numbers, in parenthesis, represent savings. Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. City Hall-12: Replace Control System Purpose: The DDC controls are a dated Barber Coleman system that does not interface with the citywide Honeywell system. The system has exceeded its expected service life; replacement is recommended before it fails. The controls are not operating properly, resulting in higher energy use and poor thermal comfort. Converting the controls to a Honeywell DDC system will ease maintenance and interoperability. Fuel and electricity will be saved if the control system is replaced and the control strategies optimized. The energy audit revealed that the building is over-ventilated, demand control ventilation is not being used, supply air reset controls are not in use, the control system is out of calibration, the system are out of adjustment, and there is opportunity to optimize the control strategies. Scope: Replace the control system, rebalance the HVAC systems, and optimize the control strategies to include the following: − Reduce minimum outside air flow − Utilize demand and schedule controlled ventilation − Utilize supply air reset control − Utilize occupancy sensor control − Demand limiting − Temperature setback Analysis: This ECO is estimated to reduce annual electricity use by 64,000 kWh, electric demand by 120 kW, and energy costs by $5,900. The energy savings will not offset the cost of control replacement but it offers incentive to prioritize replacement rather than wait until system operation is detrimental to occupant comfort and productivity. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $216,000 $0 ($108,100) $107,900 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 62 City Hall City Hall-13: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand is very steady so there is little need to educate people on demand control. City Hall-14: Add Arctic Entrance at Back Entrance Purpose: Heat will be saved if the back entrance is converted to an arctic entrance. Analysis: Arctic entrances require passage through two doors to enter/leave the building. With sufficient distance between them, one door closes before the other opens, sealing the entrance and reducing infiltration. Arctic entrances are a standard in high performance buildings. The cost of adding an arctic entrance with ADA door operators will not be offset by energy savings. This ECO is not recommended. City Hall-15: Replace Windows Purpose: Heat will be saved by replacing the windows. Scope: Replace the double pane windows with energy efficient triple pane windows. Analysis: Previous analysis has shown that replacing older double pane windows with modern, energy efficient triple pane units will not provide a life cycle savings. This ECO is not recommended. City Hall-16: Increase Duct Insulation Purpose: Heat will be saved by adding insulation to the main AHU-1 supply duct that runs in utilidors underground and on the roof. Scope: Add insulation to the main AHU-1 supply duct that runs in utilidors underground and on the roof. Analysis: The duct insulation is the same R-value as the insulation used within the building. This is less than optimal considering that the utilidor is in a much colder environment. However, the high cost of accessing the ducts will not be offset by energy savings to provide a life cycle savings. This ECO is not recommended. City Hall-17: Increase Wall Insulation Purpose: Heat will be saved by adding insulation to the exterior walls. Analysis: The walls were insulated to the standards that existed when they were constructed. The assembly is below current optimal levels of R-25+. Previous analyses have shown that that adding insulation to the wall will not provide a life cycle savings because of the high cost of replacing the interior or exterior finishes. If the EIFS is replaced in the future, additional wall insulation is warranted. City Hall-18: Increase Perimeter Insulation Purpose: Electricity will be saved by adding perimeter insulation. Analysis: The concrete footings have no perimeter insulation. This is below the current optimal level of 3” thick insulation. Previous analyses have shown that that adding insulation to the perimeter footings will not provide a life cycle savings. Alaska Energy Engineering LLC CBS Energy Audit 63 City Hall City Hall-19: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings. This ECO is not recommended. SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Electricity Current Energy Costs $36,000 Behavioral and Operational City Hall-1: Turn Off Heaters City Hall-2: Turn Off Lighting City Hall-3: Turn Off Equipment City Hall-4: Weather-strip Exterior Doors Energy Savings (Estimated) ($300) High Priority City Hall-5: Water Conserving Aerators ($360) City Hall-6a: Set Computers to Sleep Mode ($710) City Hall-6b: Turn Off Inactive Computers ($460) Medium Priority City Hall-7: Install a VFD on AHU-1 ($1,280) City Hall-8: Install HW Heater Demand Controls ($120) City Hall-9: Install Computer Room Natural Cooling System ($330) City Hall-10: Install Lighting Occupancy Sensors ($850) City Hall-11: Replace Main Entrance Doors ($570) ECO Savings ($4,980) (14%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 64 City Hall Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational City Hall-1: Turn Off Heaters $0 City Hall-2: Turn Off Lighting $0 City Hall-3: Turn Off Equipment $0 City Hall-4: Weather-strip Exterior Doors $300 Totals $300 $0 ($5,400) ($5,100) High Priority City Hall-5: Water Conserving Aerators $200 $0 ($6,700) ($6,500) City Hall-6a: Set Computers to Sleep Mode $500 $0 ($13,100) ($12,600) City Hall-6b: Turn Off Inactive Computers $500 $0 ($8,400) ($7,900) Medium Priority City Hall-7: Install a VFD on AHU-1 $7,300 $4,300 ($23,400) ($11,800) City Hall-8: Install HW Heater Demand Control $1,500 $0 ($2,300) ($800) City Hall-9: Computer Room Natural Cooling $7,500 ($3,900) ($6,000) ($2,400) City Hall-10: Install Lighting Occ. Sensors $12,000 $1,300 ($15,600) ($2,200) City Hall-11: Replace Main Entrance Doors $10,100 $0 ($10,500) ($400) Totals $39,900 $1,700 ($91,400) ($49,800) ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic electricity use • Energy and life cycle cost analysis calculations Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 42,240 93 43,040 83 40,000 87 43,440 96 168,720 Feb 37,760 75 36,400 86 43,200 94 38,560 87 155,920 Mar 37,200 74 38,960 94 39,280 88 36,880 75 152,320 Apr 30,880 68 31,600 74 30,640 88 39,440 74 132,560 May 22,880 57 29,040 69 31,360 70 21,440 82 104,720 Jun 22,160 54 21,840 58 23,040 70 28,080 58 95,120 Jul 18,960 52 23,120 53 21,120 49 22,560 55 85,760 Aug 18,400 53 24,000 54 18,080 47 20,240 55 80,720 Sep 25,600 66 21,840 59 21,920 67 24,880 65 94,240 Oct 31,440 69 27,520 73 34,040 74 31,760 78 124,760 Nov 37,520 76 44,960 94 33,440 81 36,720 82 152,640 D 37 920 98 37 600 91 43 440 88 42 480 86 161 440 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 37,920 98 37,600 91 43,440 88 42,480 86 161,440 Total 362,960 379,920 379,560 386,480 377,230 Average 30,247 70 31,660 74 31,630 75 32,207 74 31,436 Load Factor 59.6% 58.6% 57.7% 59.2% 73 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 3,479 243 3,721 3,771 277 4,048 8.8% Feb 3,751 268 4,018 3,356 243 3,599 -10.4% Mar 3,418 246 3,663 3,214 196 3,409 -6.9% Apr 2,683 246 2,929 3,431 190 3,621 23.6% May 2,744 174 2,918 1,901 221 2,122 -27.3% Jun 2,037 174 2,211 2,466 130 2,596 17.4% Jul 1,874 93 1,967 1,996 118 2,114 7.5% Aug 1,616 87 1,702 1,799 118 1,917 12.6% Sep 1,942 165 2,106 2,194 155 2,349 11.5% Oct 2,972 190 3,162 2,778 208 2,987 -5.5% Nov 2,921 218 3,139 3,200 221 3,421 9.0% Dec 3,771 246 4,017 3,690 239 3,929 -2.2% Total $ 33,207 $ 2,346 $ 35,553 $ 33,795 $ 2,315 $ 36,110 1.6% Average $ 2,767 $ 196 $ 2,963 $ 2,816 $ 193 $ 3,009 1.6% Cost ($/kWh) 0.0937 94% 6% 0.0934 -0.3% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall August 8, 2009 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 20 40 60 80 100 120 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall August 8, 2009 $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 $ 3,000 $ 3,500 $ 4,000 $ 4,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 $ 3,000 $ 3,500 $ 4,000 $ 4,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 0 20 40 60 80 100 120 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs City Hall-1: Turn Off Heaters 1 job $0 $0 City Hall-2: Turn Off Lighting 1 job $0 $0 City Hall-3: Turn Off Equipment 1 job $0 $0 City Hall-4: Weather-strip Exterior Doors 1 job $300 $300 Energy Costs Electric Energy 1 - 25 -3,500 kWh $0.085 ($5,442) Net Present Worth ($5,142) City Hall-5: Water Conserving Aerators Energy Analysis HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kWh Electric 2.5 0.5 15 -21,900 -4,281 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 6 ea $33 $200 Energy Costs August 8, 2009 0 0 0 Year 0 Year Use/Day 0 120 Energy Costs Electric Energy 1 - 25 -4,281 kWh $0.085 ($6,656) Net Present Worth ($6,456) City Hall-6a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 42 -125 15 24 -33,579 25% -8,395 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Adjust power settings 1 job $500 $500 Energy Costs Electric Energy 1 - 25 -8,395 kWh $0.085 ($13,052) Net Present Worth ($12,552) Year kW -5.3 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall August 8, 2009 City Hall-6b: Turn Off Inactive Computers Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 42 -20 15 24 -5,373 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Adjust power settings 1 job $500 $500 Energy Costs Electric Energy 1 - 25 -5,373 kWh $0.085 ($8,353) Net Present Worth ($7,853) City Hall-7: Install a VFD on AHU-1 Energy Analysis Option CFM ΔP η, fan η, m+vfd kW Hours kWh None -12,120 2.87 50% 92.4% -8.8 2,990 -26,422 VFD 7,290 2.00 50% 90.0% 3.8 2,990 11,370 Savings -15,052 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs 15 HP VFD + integration 1 ea $7,300 $7,300 Annual Costs VFD maintenance 1 - 25 2 hrs $100.00 $4,321 Energy Costs El i E 1 25 15 052 kWh $0 085 ($23 402) -10.9 Year 0 kW -0.8 Year 4.6 HP 0 Electric Energy 1 - 25 -15,052 kWh $0.085 ($23,402) Net Present Worth ($11,781) City Hall-8: Install HW Heater Demand Controls Energy Analysis Option kW Months Total kW Exist -6 12 -72 New 6 2 12 New 4 4 16 New 2 6 12 -32 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Add thermostats and rewire 1 ea $1,500 $1,500 Energy Costs Electric Demand 1 - 25 -32 kW $3.90 ($2,283) Net Present Worth ($783) Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall August 8, 2009 City Hall-9: Install Computer Room Natural Cooling System Energy Analysis Option A/C MBH COP kW Load Factor kWh Exist A/C 18 3.0 -1.8 50% -5,133 New A/C 18 3.0 1.8 50% 642 New AHU - - 0.2 50% 1,258 Savings -14 -3,234 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Natural cooling air handler, ductwork, electrical 1 ea $7,500 $7,500 Annual Costs Reduced A/C unit maintenance 1 - 25 -4 hrs $60.00 ($5,185) AHU maintenance 1 - 25 1 hrs $60.00 $1,296 Energy Costs Electric Energy 1 - 25 -3,234 kWh $0.085 ($5,027) Electric Demand 1 - 25 -14 kW $3.90 ($971) Net Present Worth ($2,387) City Hall-10: Install Lighting Occupancy Sensors Energy Analysis Room Number Area, sqft watts/sqft kWh Office 31 7,815 1.4 -8,534 Toilets 6 1,050 0.9 -1,474 Savings -10,008 ΔHours/Day -3 16 14.0 Hours/Day 2.0 Year 0 -6 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install occupancy sensor 37 ea $325 $12,025 Annual Costs Occupancy sensor maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Electric Energy 1 - 25 -10,008 kWh $0.085 ($15,560) Net Present Worth ($2,239) City Hall-11: Replace Main Entrance Doors Energy Analysis Room R,old R,new Area, sqft kBTU kWh Entrance 0.5 3.0 63 -22,995 -6,737 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace entrance doors 63 sqft $160 $10,080 Energy Costs Electric Energy 1 - 25 -6,737 kWh $0.085 ($10,475) Net Present Worth ($395) 0 Year Year 0 Factor 100% Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net City Hall August 8, 2009 City Hall-12: Replace Controls Points List Qty Unit Pts/ea AHU 1 ea 8 VAV Boxes 40 ea 1 Reheat coils 11 ea 1 Baseboard heaters 29 ea 1 Thermostats 40 ea 1 Domestic hot water 2 ea 1 AC Unit 2 ea 1 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace automatic controls 135 pts $1,600 $216,000 Energy Costs Electric Energy 1 - 25 -64,000 kWh $0.085 ($99,503) Electric Demand 1 - 25 -120 kW $3.90 ($8,560) Net Present Worth $107,937 Year Points 8 40 11 30 40 2 133 0 2 Alaska Energy Engineering LLC CBS Energy Audit 65 Fire Hall Section 5 Fire Hall INTRODUCTION The Fire Hall contains administration spaces, meeting rooms, an apparatus bay and support spaces. The building is occupied continuously. The building characteristics are: • Size: 15,930 square feet • Occupied Hours: Continuously occupied. • Occupancy: Permanent staff of eight - Monday to Friday 8:00 am to 5:00 pm. Two Engineers - all other times; one evening class per week. • HVAC Hours: Continuous • Heating and Ventilating System: Central air handling unit with constant airflow. Perimeter spaces have infloor radiant heat. • Domestic Hot Water System: Indirect hot water makers heated by the boilers. ENERGY CONSUMPTION AND COST The building energy sources are electricity and fuel oil. Fuel oil is consumed by the boiler for heat and domestic hot water and electricity supplies all other loads. The following table summarizes the energy consumption and cost. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Fuel Oil 10,000 gals $24,000 1,400 (67%) Electricity 190,000 kWh $18,000 700 (33%) Totals - $42,000 2,100 (100%) 1. Consumption is the average from 2005-2008. Costs are based on 2009 prices. Trends Fuel Oil: Consumption has been steady over the previous four years. Electricity: Electricity use was steady from 2005 to 2007 and dropped 4% in 2008. The drop is due to occupants changing their behavior and turning off lights in unoccupied rooms. Electric demand was steady at 40 kW from 2005-2008. The effective cost—energy plus demand charges—is 9.3¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 8.5¢ per kWh. Energy consumption data is located at the end of this section. Alaska Energy Engineering LLC CBS Energy Audit 66 Fire Hall DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Interior facing; insulated concrete panel; exterior face R-22 Roof Attic with batt insulation R-38 Floor Slab Concrete slab-on-grade R-2 Perimeter Concrete footing; 2: rigid insulation R-10 Windows Metal frame w/o thermal break; double pane glazing; good weather-stripping R-1.5 Doors Entrance Metal frame w/o thermal break; single pane glazing; good weather-stripping R-1.0 Overhead Insulated metal door w/o thermal break; good weather -stripping R-2 Analysis Walls: The wall insulation is near the optimal level of R-25 to R-30. Roof: The roof insulation is below optimal insulation levels of R-50 to R-60. Floor Slab: The lack of floor slab insulation is typical of past practice and there is no economical way to add insulation to the floor slabs. Perimeter: The perimeter insulation is near the optimal level of R-10 to R-15. Windows: Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken frames. Doors: Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non- thermally broken frames. The single pane glazing is below optimal insulation levels. Other Items: • The main entrance does not have an arctic entrance to minimize infiltration. • The trucks do not have a remote operator for closing the overhead doors when they depart the station. The doors stay open for 20 minutes until the service engineer arrives to close them. Heating System Description The heating system consists of two oil-fired, hot water boilers and a hydronic distribution system with constant speed pumps supplying heating water to the building. Alaska Energy Engineering LLC CBS Energy Audit 67 Fire Hall A heat exchanger separates the boiler loop from the glycol loop serving the ventilation heating coils, unit heaters, and baseboard heater. A radiant heating loop supplies in-floor heating zones throughout the building. The hydronic heating system also supplies indirect hot water heaters. The heating system has the following pumps: • Pump CP-1: Primary heat exchanger loop • Pump CP-2: Indirect hot water generators HWG-1 and HWG-2 • Pump CP-3: Boiler circulation loop • Pump CP-4: Primary radiant loop • Pump CP-5: Secondary radiant loop • Pump CP-6: Secondary heat exchanger loop Analysis The boilers are operated in a lead/standby configuration to supply year-round heating loads that occur due to Sitka’s temperate climate. Their operating thermostats have an on-off temperature differential of 10°F. A larger differential will decrease cycling losses and improve seasonal efficiency. The boilers do not have flue dampers to minimize the flow of heated air through the boiler and up the chimney when it is not operating. The pumps are manufactured by Grundfos. The larger pumps (P-1, P-5, and P-6) are not as energy efficient as custom pumps with premium efficiency motors. Converting the secondary system to variable speed pumping will decrease pumping costs by allowing pump energy consumption to vary with the heating load. The unit heaters do not have automatic valves to shut off the heating water flow when heat is not required. Ventilation System Description Air Handling Unit AHU-1: AHU-1 is an air handling unit that supplies constant flow mixed air to the rooms. The unit has a mixing box, filter section, heating coil, and supply fan. Return air from the rooms flows through the ceiling plenum back to AHU-1. Relief air flows from the ceiling plenum out a relief louver and damper in the exterior wall. Makeup Air Unit MAU-1: MAU-1 is an air handling unit that supplies 100% outside air to the apparatus bay. The unit has an outside air damper, filter section, heating coil, and supply fan. Ventilating Fan VF-1: VF-1 is a cabinet fan supplying cooling air to the boiler room. The unit has a mixing box and supply fan. Exhaust Fan EF-1: EF-1 is a roof exhaust fan that draws exhaust air from the toilet rooms. Exhaust Fan EF-2: EF-2 is a roof exhaust fan that draws exhaust air from apparatus bay. Exhaust Fan EF-3: EF-3 is a roof exhaust fan that draws exhaust air from apparatus bay. Exhaust Fan EF-4: EF-4 is a centrifugal vehicle exhaust fan. Exhaust Fan EF-5: EF-5 is a centrifugal vehicle exhaust fan. Alaska Energy Engineering LLC CBS Energy Audit 68 Fire Hall Exhaust Fan EF-6: EF-6 is a wall exhaust fan serving the fire extinguisher hood. Exhaust Fan EF-7: EF-7 is a wall exhaust fan serving the water lab hood. Analysis AHU-1 would be more efficient if it was a variable air volume system. Reconfiguring the unit will be too expensive to provide a life cycle savings. There is no boiler room heat recovery. There is no heat recovery of the EF-1 exhaust airflow. The EF-6 backdraft damper is hanging open when the fan is off. The EF-7 backdraft damper is hanging open when the fan is off. The ductwork is not sealed. Domestic Hot Water System Description Two indirect hot water generators supply domestic hot water to the building. Hot water recirculating pump CP-7 maintains hot water in the distribution piping. The lavatory faucet aerators and showerheads have a flow rate of 2.5 gpm. The faucets are not auto- sensing. Analysis Ultra-low aerators of 0.5 gpm are available for lavatory faucets. Low-flow showerheads of 1.8 gpm are available for the showers. Automatic Control System Description The building HVAC systems are controlled by local controllers and a Honeywell DDC control system that interfaces with the City’s community-wide Honeywell system. Basic Control Sequences Boilers B-1 and B-2: Operate in a lead/standby configuration. When a boiler is enabled, its operating thermostat turns the burner on at 160°F and off at 165°F. Pump CP-1: Operates when outdoor temperature is less than 75°F. Pump CP-2: Operates to maintain the DHW setpoint. Pump CP-3: Operates when CP-1 operates. Pump CP-4: The radiant heating controller operates the pump and varies the speed to supply radiant heating water at 140°F and 90°F when the outside temperature is 30°F and 60°F, respectively. Pump CP-5: Operates when outdoor temperature is less than 60°F and any radiant heating zone calls for heat. Pump CP-6: Operates when CP-1 operates. Pump CP-7: Operates continuously. Alaska Energy Engineering LLC CBS Energy Audit 69 Fire Hall Air Handling Unit AHU-1: • AHU-1 operates continuously in accordance with an occupied/unoccupied schedule. • Mixing dampers and heating coil automatic valve modulate to maintain the discharge temperature setpoint, supply minimum outside air, maintain CO2 levels, and is reset with heating and cooling requirements of the zones. • Relief dampers are controlled by a pressure sensor in the main corridor. Makeup Air Unit MAU-1: • Interlocked to operate with EF-2 or EF-3 • Heating coil automatic valve modulates to maintain the room temperature. Ventilating Fan VF-1: Operates when any boiler is firing, Exhaust Fan EF-1: EF-1 operates according to a day-night schedule. Exhaust Fan EF-2: EF-2 operates when CO levels exceed 100 ppm. Exhaust Fan EF-3: EF-3 operates when CO levels exceed 100 ppm. Exhaust Fan EF-4: EF-4 is manually controlled. Exhaust Fan EF-5: EF-5 is manually controlled. Exhaust Fan EF-6: EF-6 is manually controlled. Exhaust Fan EF-7: EF-7 is manually controlled. Analysis AHU-1: • The controls do not modulate ventilation air with occupancy. • The outside air should be scheduled to bare minimum during the night when the building is lightly occupied. • Night setback is not incorporated into the control strategy. CP-1: The pump is continuously on because water hammer occurs when it turns off. Since CP-1 is interlocked with CP-3 and CP-5, they are also on continuously. Correct the cause of the water hammer so the pumps turn off when it is warm outside. Variable speed pumping would reduce pumping energy. The HVAC systems should be retro-commissioned to optimize the energy performance. Lighting Description The interior lighting is energy efficient. Analysis There are no occupancy sensors to control lighting. Lighting was left on in unoccupied rooms. The apparatus bay is over lit the majority of the time. Interior lighting was found to be on when rooms are unoccupied. Alaska Energy Engineering LLC CBS Energy Audit 70 Fire Hall Electric Equipment Description The building has eight computers that are left on continuously. A top loading washing machine is installed. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. Front-loading washing machines require less water and are more energy efficient. ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. Fire Hall-1: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Lighting was left on in unoccupied rooms. Scope: Turning off lighting is an ECO with immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. The Fire Hall has initiated behavioral changes where occupants regularly turn off lighting in unoccupied rooms. Analysis: This ECO is recommended without analysis. Fire Hall-2: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment is an ECO with immediate payback. This ECO requires behavioral changes where occupants regularly turn off equipment when they are finished with it. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 71 Fire Hall Fire Hall-3: Minimize Boiler Short Cycling Purpose: Fuel oil will be saved if the boiler operating setpoints are changed so the boiler operates for a longer time during each cycle. The boiler operating thermostat has a fixed 10°F differential between on and off setpoints. A new controller that allows a 30°F differential will increase the amount of time the boiler operates when it is turn on, which improves seasonal efficiency. Scope: The boiler operating thermostat was replaced in July, 2009 with a model that has an adjustable temperature differential of 20-40°F. Set the differential as great as possible. As a starting point, use typical differentials of 30°F in the winter and 40°F in the summer. Analysis: This ECO is recommended without analysis. Fire Hall-4: Overhead Door Controls Purpose: Fuel oil will be saved if the fire trucks have remote controls to close the overhead doors as they leave the station. Scope: Install remote controls in each truck to close the overhead doors. Analysis: When the trucks leave the station, they have no means of closing the overhead doors. The doors stay open for about 20 minutes until the service engineer arrives. With remote controls, the doors can be closed immediately. This ECO is recommended without analysis. High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. Fire Hall-5: Reduce Apparatus Bay Lighting Purpose: Electricity will be saved by reducing the apparatus bay lighting. Scope: Turn off the switched apparatus bay lighting except during active work. A few fixtures that are wired to be continuously on will provide sufficient circulation lighting. Analysis: The apparatus bay lighting is currently continuously left on. The analysis assumes the lighting will be on 6 hours per day for active work periods and that the three direct- wired fixtures will provide sufficient illumination for circulation the rest of the day. This ECO will reduce annual electricity use by 36,000 kWh, lamp costs by $400, and energy costs by $3,100. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 ($8,600) ($55,900) ($64,300) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 72 Fire Hall Fire Hall-6: Install Water-Conserving Aerators Purpose: Fuel oil will be saved by installing water-conserving aerators on sinks and lavatories. Scope: Replace lavatory aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 40 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual fuel oil use by 50 gallons and energy costs by $120. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 $0 ($3,900) ($3,700) Note: Negative numbers, in parenthesis, represent savings. Fire Hall-7: Install Water-Conserving Shower Heads Purpose: Fuel oil will be saved by using water-conserving showerheads. Scope: Replace showerheads with low flow 1.8 gpm showerheads. Analysis: The analysis assumes that the showers are used an average of four times per day. Replacing the showerheads will reduce annual fuel oil use by 30 gallons and energy costs by $70. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 $0 ($2,200) ($2,000) Note: Negative numbers, in parenthesis, represent savings. Fire Hall-8: Reduce Computer Energy Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Alaska Energy Engineering LLC CBS Energy Audit 73 Fire Hall Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Analysis: The Fire Hall has eight computers. The analysis assumes that the computers are in use for nine hours per day during the workweek. The power settings were not checked on each machine, so the following analysis assumes that 25% of the computers are not set to enter sleep mode when inactive. It is assumed that 25% of the computers are not set to sleep mode. Setting the power settings from screen saver to sleep mode will reduce annual electricity use by 1,600 kWh and energy costs by $140. Turning inactive computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 1,000 kWh and energy costs by $90. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $200 $0 ($2,500) ($2,300) Turn Off $200 $0 ($1,600) ($1,400) Total $400 $0 ($4,100) ($3,700) Note: Negative numbers, in parenthesis, represent savings. Fire Hall-9: Install Unit Heater Automatic Valve Purpose: Fuel oil will be saved if each unit heater has an automatic valve that shuts off the hydronic flow when heat is not needed. Currently, the heater coil is continuously hot which results in convective heat loss when the heater fan is not operating. While some of the heat loss may be useful, it is often not. Scope: Install an automatic valve on each unit heater to shut off the hydronic heating flow when heat is not needed. Analysis: This ECO will reduce annual fuel oil use by 60 gallons and energy costs by $130. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $800 $0 ($4,300) ($3,500) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 74 Fire Hall Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. Fire Hall-10: Boiler Flue Damper Purpose: Heat will be saved by installing a flue damper in the boiler chimney to minimize the flow of heated air through the boiler and up the chimney. Scope: Install a damper in each boiler flue and control it to open prior to firing the boiler. Analysis: This ECO will improve the boiler seasonal efficiency by a minimum of 1.5% and reduce annual fuel oil use by 140 gallons and energy costs by $290. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $4,000 $1,300 ($10,600) ($5,300) Note: Negative numbers, in parenthesis, represent savings. Fire Hall-11: Boiler Room Heat Recovery Purpose: Heat will be saved if heat from the boiler room is recovered and transferred to the apparatus bay. Scope: Install a heat recovery unit in the boiler room. Install ductwork to circulate boiler room air through one side of the heat recovery cell. Install ductwork to supply the heated air to the apparatus bay and return it. Analysis: The analysis assumes that a boiler loses 2% to jacket losses. The HRU is assumed to recover 40% of the heat loss. This ECO will reduce annual fuel oil use by 560 gallons, increase electricity use by 6,000 kWh to operate the fans, with a net energy savings of $800. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $15,500 $2,600 ($32,900) ($14,800) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 75 Fire Hall Fire Hall-12: Retro-commission Building Purpose: Fuel and electricity will be saved if the building energy systems are optimized through a retro-commissioning process. The energy audit revealed that the building is over-ventilated, demand control ventilation is not properly controlled, supply air reset controls are not in use, and there is opportunity to optimize the control strategies. Scope: Retro-commission the building with a focus on the following: − Optimize automatic control strategies − Reduce minimum outside air flow − Optimize demand controlled ventilation (CO2 sensors) − Utilize scheduled ventilation − Utilize supply air reset control − Occupancy sensor control − Temperature setback of unoccupied rooms − Utilize night setback Analysis: The analysis conservatively assumes that retro-commissioning will reduce fuel oil use by 6% and electricity use by 1% This will reduce annual electricity use by 1,900 kWh, fuel oil use by 600 gallons and energy costs by $1,600.The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $24,200 $0 ($48,900) ($24,700) Note: Negative numbers, in parenthesis, represent savings. Fire Hall-13: Increase Roof Insulation Purpose: Fuel oil will be saved by adding insulation to the roof. Scope: Add additional blown-in fiberglass insulation to increase the roof R-value from R-38 to R-58. Analysis: This ECO will reduce annual fuel oil use by 270 gallons and energy costs by $660. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $14,900 $0 ($20,900) ($6,000) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 76 Fire Hall Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. Fire Hall-14: Replace Grundfos Pumps P-1, P-5 and P-6 Purpose: Electricity will be saved if the Grundfos pumps are replaced with custom pumps with NEMA Premium® Motors. Scope: Replace pumps P-1, P-5 and P-6 with custom pumps. Analysis: Grundfos pumps require minimal maintenance and are easily replaced. However, they are less energy efficient than custom pumps because they are not customized to the system operating condition. In addition, the integral motors on larger pumps are less efficient than NEMA Premium® motors. The result is that Grundfos pumps often have higher energy costs. This ECO will reduce annual electricity use by 6,000 kWh, electric demand by 9 kW, and energy costs by $570. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $7,000 $7,800 ($10,400) $4,300) Note: Negative numbers, in parenthesis, represent savings. Fire Hall-15: Lighting Occupancy Sensor Control Purpose: Electricity use will be reduced by installing occupancy sensors that will automatically turn the lighting off when rooms are unoccupied. The Fire Hall has implemented behavioral changes where lighting is turned off in unused rooms. An occupancy sensor can be a more reliable method of controlling the lighting. Scope: Install occupancy sensors in offices, toilet rooms, and other rooms. Analysis: The analysis is based on a 150 square foot office where the occupancy sensor will turn the lights off an additional two hours per day. This ECO will reduce annual electricity use by 110 kWh and energy costs by $9. The following table summarizes the life cycle cost analysis. This ECO is not recommended due to the high cost of retrofitting occupancy sensors into an existing building. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $1,200 ($20) ($160) $1,020 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 77 Fire Hall Fire Hall-16: Add Arctic Entrance Purpose: Heat will be saved if the main entrance is converted to an arctic entrance. Scope: Convert the main entrance to an arctic entrance. Analysis: Arctic entrances require passage through two doors to enter/leave the building. With sufficient distance between them, one door closes before the other opens, sealing the entrance and reducing infiltration. The energy savings is not sufficient to offset the high cost of constructing the arctic entrance in an existing building and installing ADA operators for the inner door. This ECO is not recommended. Fire Hall-17: Replace Non-thermally Broken Metal Windows and Doors Purpose: Heat will be saved if the non-thermally broken windows and doors are replaced with thermally broken units. Analysis: Thermally broken window and door frames have separators between the inside and outside surfaces so there is not a direct conductive path through the metal. The thermal break reduces heat loss and keeps inner surfaces warmer, which precludes the formation of condensation. Previous analyses have shown that replacing the windows or doors will not provide a life cycle savings. This ECO is not recommended. Fire Hall-18: Variable Speed Pumping Purpose: Electricity will be saved if the hydronic heating system is converted to variable flow pumping. Analysis: The variable speed pumping analysis for the Centennial Building did not provide a life cycle savings. The Fire Hall has similar loads and pump sizes. It is assumed the result will be the same. This ECO is not recommended. Fire Hall-19: Convert to Variable Air Flow (AHU-1) Purpose: Fuel oil and electricity will be saved by converting AHU-1 from constant flow to variable. Analysis: AHU-1 is a smaller system, which limits the energy savings potential of a VAV system. However, the energy savings potential is greatly enhanced by the continuous operating hours combined with the highly variable occupancy and heat gain. It is likely that if AHU-1 were an original VAV system, it would have provided a life cycle savings. Converting the system will have too high a cost to provide a life cycle savings. This ECO is not recommended. Fire Hall-20: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand is very steady so there is little need to educate people on demand control. Alaska Energy Engineering LLC CBS Energy Audit 78 Fire Hall Fire Hall-21: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings. This ECO is not recommended. SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Fuel Oil Electricity Total Current Energy Costs $24,000 $18,000 $42,000 Behavioral and Operational Fire Hall-1: Turn Off Lighting Fire Hall-2: Turn Off Equipment Fire Hall-3: Replace Boiler Thermostat Fire Hall-4: Provide Overhead Door Controls Energy Savings (Estimated) ($120) ($30) ($150) High Priority Fire Hall-5: Implement Apparatus Bay Lighting Control $0 ($3,060) ($3,060) Fire Hall-6: Install Water Conserving Aerators ($120) $0 ($120) Fire Hall-7: Install Water Conserving Showerheads ($70) $0 ($70) Fire Hall-8a: Set Computers to Sleep Mode $0 ($140) ($140) Fire Hall-8b: Turn Off Inactive Computers $0 ($90) ($90) Fire Hall-9: Install Unit Heater Automatic Valves ($130) $0 ($130) Medium Priority Fire Hall-10: Install Boiler Flue Damper ($330) $0 ($330) Fire Hall-11: Install Boiler Room Heat Recovery Unit ($1,350) $550 ($800) Fire Hall-12: Retro-commission HVAC Systems ($1,440) ($160) ($1,600) Fire Hall-13: Increase Roof Insulation ($660) $0 ($660) ECO Savings ($4,220) ($2,930) ($7,150) (18%) (16%) (17%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 79 Fire Hall Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational Fire Hall-1: Turn Off Lighting $0 Fire Hall-2: Turn Off Equipment $0 Fire Hall-3: Replace Boiler Thermostat $400 Fire Hall-4: Provide Overhead Door Controls $3,400 Totals $3,800 $0 ($4,400) ($600) High Priority Fire Hall-6: Implement Apparatus Bay Light Control $200 ($8,600) ($55,900) ($64,300) Fire Hall-7: Install Water Conserving Aerators $200 $0 ($3,900) ($3,700) Fire Hall-8: Install Water Conserving Showerheads $200 $0 ($2,200) ($2,000) Fire Hall-9a: Set Computers to Sleep Mode $200 $0 ($2,500) ($2,300) Fire Hall-9b: Turn Off Inactive Computers $200 $0 ($1,600) ($1,400) Fire Hall-10: Install Unit Heater Automatic Valves $800 $0 ($4,300) ($3,500) Medium Priority Fire Hall-11: Install Boiler Flue Damper $4,000 $1,300 ($10,600) ($5,300) Fire Hall-12: Install Boiler Room Heat Recovery $15,500 $2,600 ($32,900) ($14,800) Fire Hall-13: Retro-commission HVAC Systems $24,200 $0 ($48,900) ($24,700) Fire Hall-14: Increase Roof Insulation $14,900 $0 ($20,900) ($6,000) Totals $64,200 ($4,700) ($188,200) ($128,700) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 80 Fire Hall ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic fuel oil consumption • Historic electricity use • Energy and life cycle cost analysis calculations 0 2,000 4,000 6,000 8,000 10,000 0 2,000 4,000 6,000 8,000 10,000 12,000 2005 2006 2007 2008 Degree DaysGallonsFuel Oil Consumption Gallons Degree Days Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 20,720 51 17,440 49 18,400 41 16,480 38 73,040 Feb 17,520 46 15,920 39 17,600 43 15,600 41 66,640 Mar 17,040 44 15,200 36 16,240 42 16,240 34 64,720 Apr 15,200 44 15,120 36 17,840 39 14,960 35 63,120 May 16,880 48 17,120 39 15,360 43 12,960 38 62,320 Jun 15,520 38 13,360 32 14,880 31 15,120 34 58,880 Jul 13,440 37 16,400 39 14,400 35 14,880 34 59,120 Aug 16,080 36 15,120 34 15,280 42 16,000 39 62,480 Sep 14,880 45 14,880 39 16,560 38 15,280 46 61,600 Oct 17,120 43 17,600 40 15,280 37 14,960 42 64,960 Nov 16,320 38 17,440 45 16,160 37 17,680 40 67,600 D 17 680 36 21 280 46 16 880 42 17 920 42 73 760 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 17,680 36 21,280 46 16,880 42 17,920 42 73,760 Total 198,400 196,880 194,880 188,080 194,560 Average 16,533 42 16,407 40 16,240 39 15,673 39 16,213 Load Factor 53.8% 56.9% 56.7% 55.5% 40 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 1,643 62 1,704 1,480 49 1,529 -10.3% Feb 1,575 71 1,646 1,405 62 1,466 -10.9% Mar 1,459 68 1,527 1,459 37 1,496 -2.0% Apr 1,595 55 1,650 1,350 40 1,390 -15.8% May 1,384 71 1,455 1,180 52 1,233 -15.3% Jun 1,344 24 1,368 1,364 37 1,401 2.4% Jul 1,303 40 1,342 1,344 34 1,377 2.6% Aug 1,378 65 1,442 1,439 55 1,494 3.6% Sep 1,486 52 1,539 1,378 83 1,461 -5.0% Oct 1,378 46 1,424 1,350 68 1,418 -0.4% Nov 1,452 46 1,498 1,582 59 1,640 9.5% Dec 1,514 68 1,581 1,602 65 1,667 5.4% Total $ 17,509 $ 668 $ 18,177 $ 16,931 $ 640 $ 17,571 -3.3% Average $ 1,459 $ 56 $ 1,515 $ 1,411 $ 53 $ 1,464 -3.3% Cost ($/kWh) 0.0933 96% 4% 0.0934 0.2% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall August 8, 2009 0 5,000 10,000 15,000 20,000 25,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 0 0 0 0 0 0 0 0 0 0 0 0 5,000 10,000 15,000 20,000 25,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 10 20 30 40 50 60 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall August 8, 2009 $ 0 $ 200 $ 400 $ 600 $ 800 $ 1,000 $ 1,200 $ 1,400 $ 1,600 $ 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 200 $ 400 $ 600 $ 800 $ 1,000 $ 1,200 $ 1,400 $ 1,600 $ 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 0 5 10 15 20 25 30 35 40 45 50 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Fire Hall-1: Turn Off Lighting 1 job $0 $0 Fire Hall-2: Turn Off Equipment 1 job $0 $0 Fire Hall-3: Replace Boiler Thermostat 1 job $400 $400 Fire Hall-4: Provide Overhead Door Controls 4 ea $850 $3,400 Energy Costs Electric Energy 1 - 25 -380 kWh $0.085 ($591) Fuel Oil 1 - 25 -50 gal $2.40 ($3,827) Net Present Worth ($617) Fire Hall-5: Implement Apparatus Bay Lighting Control Energy Analysis Option Fixtures watts/ea kW kWh Existing -19 288 -5.5 -47,935 100% 19 288 5.5 11,984 -35,951 Lamp Cost Option lamps $/lamp Life hrs $yr August 8, 2009 Year 0 0 0 0 2,190 Hours Hours 8,760 Option lamps $/lamp Life, hrs $,yr Existing -4 8.00 10,000 -28 Scheduled 4 8.00 10,000 7 Savings -21 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Implementation 1 ea $200 $200 Annual Costs Lamp savings 1 - 25 19 fixtures ($21.02) ($8,629) Energy Costs Electric Energy 1 - 25 -35,951 kWh $0.085 ($55,894) Net Present Worth ($64,324) Fire Hall-6: Install Water Conserving Aerators Energy Analysis HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kBTU Boiler Effic Fuel, gals Indirect 2.5 0.5 15 -7,300 -4,871 70% -52 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 4 ea $50 $200 Energy Costs Fuel Oil 1 - 25 -52 gal $2.40 ($3,944) Net Present Worth ($3,744) Year 0 0 Use/Day 40 Year Hours 8,760 2,190 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall August 8, 2009 Fire Hall-7: Install Water Conserving Showerheads Energy Analysis HW Heater Exist GPM New GPM Duration, min Gal saved Heat, kBTU Boiler Effic Fuel, gals Indirect 2.5 1.8 5 -5,110 -2,770 70% -29 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace showerhead 3 ea $67 $201 Energy Costs Fuel Oil 1 - 25 -29 gal $2.40 ($2,243) Net Present Worth ($2,042) Fire Hall-8a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 8 -125 15 24 -6,396 25% -1,599 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Change computer power settings 1 lob $200 $200 Energy Costs Electric Energy 1 - 25 -1,599 kWh $0.085 ($2,486) Net Present Worth ($2,286) Fire Hall-8b: Turn Off Inactive Computers kW -1.0 Use/Day 4 Year 0 Year 0 Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 8 -20 15 24 -1,023 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Change computer power settings 1 lob $200 $200 Energy Costs Electric Energy 1 - 25 -1,023 kWh $0.085 ($1,591) Net Present Worth ($1,391) Fire Hall-9: Install Unit Heater Automatic Valves Energy Analysis Loss, BTUH Number Factor Loss, kBTU Fuel, gals 1,500 2 20% -5,256 -56 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install AV and controls 2 ea $400 $800 Energy Costs Fuel Oil 1 - 25 -56 gal $2.40 ($4,257) Net Present Worth ($3,457) kW -0.2 Year Boiler Effic 70% 0 Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall August 8, 2009 Fire Hall-10: Install Boiler Flue Damper Energy Analysis Input, gph FO Gallons On Hours Off Hours CFM w/damper kBTU Boiler Effic Fuel, gals 5.6 9,700 1,732 7,028 5 -13,142 70% -139 20%98.6% Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install flue damper 2 ea $2,000 $4,000 Annual Costs Flue damper maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Fuel Oil 1 - 25 -139 gal $2.40 ($10,643) Net Present Worth ($5,347) Fire Hall-11: Install Boiler Room Heat Recovery Unit Energy Analysis Boiler MBH Factor Loss, MBH Factor kBTU Boiler Effic Fuel, gals CFM 756 2% 15 40% -52,980 70% -561 687 HP η, motor kW Hours 0.75 81.0% 0.7 8,760 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs 700 CFM h i 1 $7 500 $7 500 CFM w/o damper 15 Year kWh 6,051 Year 0 -6 0 Recovery, MBH 700 CFM heat recovery unit 1 ea $7,500 $7,500 Supply and return ductwork 1 ea $5,000 $5,000 Electric and controls 1 ea $3,000 $3,000 Annual Costs HRV maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 6,051 kWh $0.085 $9,408 Electric Demand 1 - 25 8 kW $3.90 $591 Fuel Oil 1 - 25 -561 gal $2.40 ($42,906) Net Present Worth ($14,815) Fire Hall-12: Retro-commission HVAC Systems Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Develop control sequences 1 ea $3,000 $3,000 Automatic control modifications 3 pts $1,500 $4,500 Retro-commissioning Modify control drawings 16 hrs $140 $2,240 Modify control software 16 hrs $140 $2,240 On-site Implementation and travel, including commissioning 40 hrs $140 $5,600 Perdiem and Travel 1 ea $2,500 $2,500 Closeout 8 hrs $140 $1,120 Verification 1 ea $3,000 $3,000 Energy Costs Electric Energy 1 - 25 -1,900 kWh $0.085 ($2,954) Fuel Oil 1 - 25 -600 gal $2.40 ($45,918) Net Present Worth ($24,672) 0 Year 0 0 0 0 0 0 0 0 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall August 8, 2009 Fire Hall-13: Increase Roof Insulation Energy Analysis Option R-value Tin Tout Loss, kBTU Boiler Effic Fuel, gals Exist -38 65 41 -74,884 70% -792 Added 58 65 41 49,062 70% 519 Savings -273 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Blow-in R-20 attic insulation 13535 sqft $1.10 $14,889 Energy Costs Fuel Oil 1 - 25 -273 gal $2.40 ($20,912) Net Present Worth ($6,023) Fire Hall-14: Replace Grundfos Pumps Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh Exist P-1 - - - - -0.8 8,760 -7,008 Exist P-5 - - - - -0.57 8,760 -4,993 Exist P-6 - - - - -0.80 8,760 -7,008 New P-1 69 18 65% 75.5% 0.5 8,760 4,181 New P-5 36 32 60% 85.5% 0.4 8,760 3,710 New P-6 55 28 62% 85.5% 0.5 8,760 4,799 Si 9 6 320 Year 13,535 Area 13,535 0.6 0.5 0.5 - BHP - - 0 Savings -9 -6,320 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace P-1 1 ea $2,000 $2,000 Replace P-5 and P-6 2 ea $2,500 $5,000 Annual Costs Pump maintenance - Custom Pump 1 - 25 6 hr $60.00 $7,777 Energy Costs Electric Energy 1 - 25 -6,320 kWh $0.085 ($9,826) Electric Demand 1 - 25 -9 kW $3.90 ($618) Net Present Worth $4,334 0 Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Fire Hall August 8, 2009 Fire Hall-15: Install Office Occupancy Sensors Energy Analysis Option Area, sqft watts/sqft watts kWh/yr Switch 150 -1.4 -210 -420 OS 150 1.4 210 315 Savings -105 Lamp Cost Option lamps $/lamp Life, hrs $,yr Existing -6 3.50 10,000 -4.20 Scheduled 6 3.50 10,000 3.15 Savings -1.05 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install occupancy sensor 1 ea $1,200 $1,200 Annual Costs Increased lamp life 1 - 25 1 ea ($1.05) ($23) Energy Costs Electric Energy 1 - 25 -105 kWh $0.085 ($163) Net Present Worth $1,014 hours/day 8 6 Hours 2,000 1,500 Year 0 This page intentionally left blank Alaska Energy Engineering LLC CBS Energy Audit 81 Library Section 6 Library INTRODUCTION The Library Building contains stack areas, reading areas, children’s area, computer workstations, and administrative spaces. The building characteristics are: • Size: 7,500 square feet • Occupied Hours: Monday-Thursday 8:00 am to 9:00 pm; Friday 9:00 am to 6:00 pm; Saturday and Sunday 12:00 pm to 9:00 pm • Occupancy: Normal Library Hours Monday-Friday 10:00 am to 9:00 pm; Saturday and Sunday 1:00 pm to 9:00 pm. Staff arrives 1-2 hours prior to opening • HVAC Hours: Monday-Thursday 7:45 am to 9:00 pm; Friday 9:00 am to 6:00 pm; Saturday and Sunday 12:00 pm to 9:00 pm • Heating and Ventilating System: Two central air handling units with constant airflow and duct heating coils • Domestic Hot Water System: Electric hot water heater ENERGY CONSUMPTION AND COST The building energy sources are electricity and fuel oil. Fuel oil is consumed by the boiler for heat and part of the domestic hot water load and electricity supplies all other loads. The following table summarizes the energy consumption and cost. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Fuel Oil 3,900 gals $9,400 530 (62%) Electricity 96,000 kWh $9,200 330 (38%) Totals - $18,600 860 (100%) 1. Consumption is the average from 2003-2008. Costs are based on 2009 prices. Trends Fuel Oil: Fuel use declined after the HVAC Upgrade in 2004. It has been consistent in recent years. Electricity: Electricity use is steady month-to-month but is increasing slowly each year. March and April of 2008 were exceptional months where use increased dramatically. The Library does not incur demand charges because the peak monthly demand is below 25 kW. Effective cost—energy plus demand charges—is 9.3¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 9.0¢ per kWh. Energy consumption data is located at the end of this section. Alaska Energy Engineering LLC CBS Energy Audit 82 Library DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Gyp. Bd; 2x4 wd studs; R-11 batt; sheathing; cedar siding R-10 Roof 3x6 wood deck; 5/8” plywood; 3” rigid; ½” plywood, wood shakes R-18 Floor Slab Concrete slab-on-grade R-2 Perimeter Concrete footing; no insulation R-1 Windows Metal frame w/o thermal break; double pane R-1.5 Doors Main Entrance Metal frame/door w/o thermal break; single pane; poor weather-stripping R-1.5 Others Metal frame/door w/o thermal breaks; poor weather-stripping R-2.5 Analysis Walls: The wall insulation is below optimal levels of R-25 to R-30. Adding insulation to existing walls does not typically provide a life cycle savings due to the high cost of replacing interior or exterior surfaces. If the cladding is replaced, the investment in additional insulation will provide a life cycle savings. Roof: The roof insulation is below the optimal insulation range of R-50 to R-60. Adding insulation does not typically provide a life cycle savings due to the high cost of replacing the wood shingles. When the shingles are replaced, adding insulation will provide a life cycle savings. Floor Slab: The lack of floor slab insulation is typical of past practice and there is no economical way to add insulation to the floor slabs. Perimeter: The lack of perimeter insulation is below optimal levels of R-10 to R-15. There is no economical way to add insulation to the perimeter. Windows: None of the windows is optimally insulated. Typically, replacing double pane windows does not offer a life cycle savings. Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken frames. Good weather-stripping that minimizes infiltration is essential to thermal performance. Doors: The doors are not optimally insulated. There is incentive to replace doors with single pane windows. Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non-thermally broken doors. Good weather-stripping that minimizes infiltration is essential to thermal performance. Other items: • The workroom door lockset is permanently locked. Library staff keeps the door propped open so they can enter during the day without a key. Providing a lockset that can be unlocked will allow entrance without keeping the door held open. • The main entrance is an arctic entrance with a set of inner and outer doors. The inner doors are held open, negating the ability of the entrance to minimize infiltration. Alaska Energy Engineering LLC CBS Energy Audit 83 Library Heating System Description The heating system consists of an oil-fired, hot water boiler and a hydronic distribution system. The hydronic heating system has a primary/secondary configuration where a primary pump circulates water through the boiler and secondary pumps distribute the water to the heating units. The primary and secondary pumps are constant speed pumps that have constant energy use without regard to the heating load. The heating units consist of heating coils in the air handling units, duct-mounted heating coils and a convector. The heating system has the following pumps: • Primary Pump P-5: Boiler circulation • Secondary Pump P-1: AHU-1 heating coil • Secondary Pump P-2: Convector • Secondary Pump P-3: AHU-2 heating coil • Secondary Pump P-4: Duct heating coils Analysis The boiler is operated year-round due to Sitka’s moderate summer climate. The operating thermostat has an on-off temperature differential of 20°F. A larger differential will decrease cycling losses and improve seasonal efficiency. The boiler does not have a flue damper to minimize the flow of heated air through the boiler and up the chimney when it is not operating. Pump P-3 is not interlocked to turn off when AHU-2 is off. Converting the secondary system to variable speed pumping will decrease pumping costs by varying pumping energy with heating loads. Ventilation System Description Air Handling Unit AHU-1: AHU-1 is an air handling unit that supplies constant flow mixed air to the north (older) end of the building. The unit has a mixing box, filter section, heating coil, and supply fan. Air Handling Unit AHU-2: AHU-2 is an air handling unit that supplies constant flow mixed air to south (newer) end of the building. The unit has a mixing box, filter section, heating coil, and supply fan. The system serves four zones with a duct-mounted heating coil in the ductwork to each zone. Exhaust Fan EF-1: EF-1 is a roof exhaust fan that draws exhaust air from the toilet rooms and janitor’s closet. Alaska Energy Engineering LLC CBS Energy Audit 84 Library Domestic Hot Water System Description A 50-gallon electric hot water heater supplies the building. The lavatory faucet aerators have a flow rate of 2.5 gpm. Analysis Ultra-low aerators of 0.5 gpm are available for lavatory faucets. Automatic Control System Description The building HVAC systems are controlled by a Honeywell DDC system that interfaces with the City’s community-wide system and by local controls. Basic Control Sequences Heating System: • Enabled when outside temperature is less than 65°F and either AHU is operating. • Enabled when outside temperature is less than 35F Primary Pump P-5: Operates when heating system is enabled. Boiler B-1: • Boiler is enabled two minutes after P-5 is operating. • When enabled, operating thermostat turns the burner on at 145°F and off at 165°F. Secondary Pump P-1: Operates when AHU-1 heating coil calls for heat. Secondary Pump P-3: Operates when AHU-2 heating coil calls for heat. Secondary Pump P-2: Operates when convector calls for heat. Secondary Pump P-4: Operates when any duct heating coil calls for heat. Air Handling Unit AHU-1: • Fan operates according to an occupied/unoccupied schedule. • Mixing dampers modulate to maintain a minimum of 15% outside air. • Mixing dampers modulate beyond minimum outside air to maintain CO2 levels. • Heating coil automatic valve modulates to maintain room temperature. Air Handling Unit AHU-2: • Fan operates according to an occupied/unoccupied schedule. • Mixing dampers modulate to maintain a minimum of 15% outside air. • Mixing dampers modulate beyond minimum outside air to maintain CO2 levels. • Heating coil automatic valve modulates to maintain supply air set point. • Zone heating coil automatic valve modulates to maintain room temperature. Alaska Energy Engineering LLC CBS Energy Audit 85 Library Exhaust Fan EF-1: Fan Operates when AHU-1 or AHU-2 is in occupied mode. Analysis Boiler B-1: Expanding the operating differential to 25°-30°F will decrease cycling and improve seasonal efficiency. Pump P-3 is not interlocked to turn off when AHU-2 is off. AHU-2 is over-ventilating with an outside air percentage of 48% during a period of normal CO2 levels. Lighting Description The interior lighting has been upgraded to energy efficient lighting. The exterior canopy is lit by metal halide lighting. Electric Equipment Description The building has 24 computers that are left on continuously. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces energy consumption and conserves hydroelectric resources. ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. Library-1: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment is an ECO with immediate payback. This ECO requires behavior changes where occupants regularly turn off equipment when they are finished with it. Analysis: This ECO is recommended without analysis. Library-2: Interlock Pumps Purpose: Electricity will be saved if pump P-3 is interlocked to turn off with the unit. Scope: Revise the control sequence so pump P-3 operates when AHU-3 is calling for heat. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 86 Library Library-3: Replace Workroom Lockset Purpose: Heat will be saved if the Workroom lockset is replaced. The current lockset is permanently locked. Library staff prop the door open so they can enter it during the workday. If the lockset could be unlocked, the door would remain closed. Scope: Replace the workroom exterior door lockset. Analysis: This ECO is recommended without analysis. Library-4: Replace Boiler Thermostat Purpose: Fuel oil will be saved if the boiler operating setpoints are changed so the boiler operates for a longer time during each cycle. The thermostat has a fixed 20°F differential between on and off setpoints. A new controller with a larger differential will increase the amount of time the boiler operates each cycle, which improves seasonal efficiency. Scope: The boiler operating thermostat was replaced in June, 2009 with a model that has an adjustable temperature differential of 20-40°F. Set the differential as great as possible while supply sufficient heat. As a starting point, use typical differentials of 30°F in the winter and 40°F in the summer. Analysis: This ECO is recommended without analysis. Library-5: Weather-Strip Exterior Doors Purpose: Heat will be saved if exterior doors are properly weather-stripped to reduce infiltration. Scope: Install or repair the weather-stripping on all exterior doors. Analysis: This ECO is recommended without analysis. High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. Library-6: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The Computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use and additional to 15-25 watts. Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows turning off the computers overnight. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Alaska Energy Engineering LLC CBS Energy Audit 87 Library Analysis: The Library has 24 computers. It is assumed that 25% of the computers are not set to sleep mode. The analysis assumes the computers are in use an average of 12 hours per day. Setting the power settings on 25% of the computers from screen saver to sleep mode will reduce annual electricity use by 3,300 kWh and energy costs by $300. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 2,100 kWh and energy costs by $190. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $200 $0 ($5,400) ($5,200) Turn Off $200 $0 ($3,500) ($3,300) Total $400 $0 ($8,900) ($8,500) Note: Negative numbers, in parenthesis, represent savings. Library-7: Install Water-Conserving Aerators Purpose: Fuel oil will be saved by using water-conserving aerators on lavatories and kitchen sink. Scope: Replace aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 75 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual electric use by 710 kWh and energy costs by $65. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $100 $0 ($1,200) ($1,100) Note: Negative numbers, in parenthesis, represent savings. Library-8: Boiler Flue Damper Purpose: Heat will be saved by installing a flue damper in the boiler chimney to minimize the flow of heated air through the boiler and up the chimney. Scope: Install a damper in the boiler flue and control it to open prior to firing the boiler. Analysis: This ECO will improve the boiler seasonal efficiency by a minimum of 2% and reduce annual fuel oil use by 80 gallons and energy costs by $190. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $2,000 $600 ($6,000) ($3,400) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 88 Library Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. Library-9: Boiler Room Heat Recovery Purpose: Heat will be saved if heat from the boiler room is recovered and transferred to the general stacks area. Scope: Install a heat recovery unit in the boiler room. Install ductwork to circulate boiler room air through one side of the heat recovery cell. Install ductwork to supply the heated air to the general stacks area. Analysis: The analysis assumes that the boiler loses 2% to jacket losses. The HRU is assumed to recover 50% of the heat loss. This ECO will reduce annual fuel oil use by 290 gallons, increase electricity use by 3,100 kWh to operate the fans, with a net energy savings of $420. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $11,000 $2,600 ($17,200) ($3,600) Note: Negative numbers, in parenthesis, represent savings. Library-10: Retro-commission Building Purpose: Fuel and electricity will be saved if the building energy systems are optimized through a retro-commissioning process. The energy audit revealed that the building is over-ventilated, demand control ventilation is not operating properly, supply air reset controls are not in use, and there is opportunity to optimize the control strategies. Scope: Retro-commission the building with a focus on the following: − Optimize automatic control strategies − Reduce minimum outside air flow − Scheduled ventilation control − Demand controlled ventilation − Supply air reset control Analysis: The analysis conservatively assumes that retro-commissioning will reduce fuel oil use by 8% and electricity use by 1% This will reduce annual electricity use by 550 kWh, fuel oil use by 310 gallons and energy costs by $800.The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $19,600 $0 ($24,600) ($5,000) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 89 Library Library-11: Replace Entrance Glazing Purpose: Heat will be saved if the single pane glazing within the main entrance windows and doors is replaced with double pane glazing units. Scope: Replace single pane glazing units in the outer entrance windows and doors with better insulating glazing units installed in the existing metal frames. Analysis: This ECO will reduce annual fuel oil use by 75 gallons and energy costs by $180. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $4,900 $0 ($5,800) ($900) Note: Negative numbers, in parenthesis, represent savings. Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. Library-12: Install Ceiling Fans Purpose: Heat will be saved by installing ceiling fans to move warm air down to floor level. Scope: Install four ceiling fans with variable speed controls. Analysis: The analysis assumes that the ceiling fans will keep the upper level of the library 10°F cooler, reducing heat loss through the roof. This ECO will reduce annual fuel oil use by 170 gallons but increase annual electricity use by 1,300 kWh. The result is a net annual energy savings of $290. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $11,000 $0 ($10,800) $200 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 90 Library Library-13: Upgrade HVAC Motors Purpose: Electricity will be saved if inefficient motors are upgraded to NEMA Premium® motors. Scope: Replace the motors in AHU-1 and AHU-2 with NEMA Premium® motors. Analysis: This ECO will reduce annual electricity use by 650 kWh and energy costs by $60. The energy savings is unable to offset the cost of replacement, primarily because the motors are relatively new and of moderate efficiency. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $1,300 $0 ($1,100) $200 Note: Negative numbers, in parenthesis, represent savings. Library-14: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand is very steady so there is little need to educate people on demand control. Library-15: Close Inner Entrance Doors Purpose: Heat will be saved if the inner entrance doors are closed so that the entrance functions as an arctic entrance. Scope: Close the inner entrance doors during the primary heating season of September 1 to May 1. Install an ADA door operator on one of the inner doors. Analysis: The life cycle energy savings is insufficient to offset the high cost of installing an ADA operator. This ECO is not recommended. Library-16: Replace Non-thermally Broken Metal Windows and Doors Purpose: Heat will be saved if the non-thermally broken windows and doors are replaced with thermally broken units. Analysis: Thermally broken window and door frames have separators between the inside and outside surfaces so there is not a direct conductive path through the metal. The thermal break reduces heat loss and keeps inner surfaces warmer, which precludes the formation of condensation. Previous analyses have shown that replacing the windows or doors will not provide a life cycle savings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 91 Library Library-17: Increase Wall Insulation Purpose: Heat will be saved by adding insulation to the exterior walls. Analysis: The walls are constructed of 2x4 wood studs with cavity insulation. The assembly has an R-10 insulation level, which is below current optimal levels of R-25+. Previous analyses have shown that that adding insulation to the wall will not provide a life cycle savings because of the high cost of replacing the interior or exterior finishes. If the finishes are updated in the future, additional wall insulation is warranted. Library-18: Increase Perimeter Insulation Purpose: Electricity will be saved by adding perimeter insulation. Analysis: The concrete footings have no perimeter insulation. This is below the current optimal level of 3” thick insulation. Previous analyses have shown that that adding insulation to the perimeter footings will not provide a life cycle savings. Library-19: Increase Roof Insulation Purpose: Heat will be saved by adding insulation to the roof. Analysis: The roof is insulated with a layer of 3” rigid insulation on the roof deck. The assembly has an R-18 insulation level, which is below current optimal levels of R- 50+. Previous analyses have shown that that adding insulation to the roof will not provide a life cycle savings because of the high cost of removing and installing the shingles. If the shingles are replaced in the future, additional insulation is warranted. Library-20: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The Library leakage rate is likely less because much of the ductwork is exposed and any leakage is somewhat beneficial. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings or repainting exposed ducts. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 92 Library SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Fuel Oil Electricity Total Current Energy Costs $9,400 $9,200 $18,600 Behavioral and Operational Library-1: Turn Off Equipment Library-2: Interlock Pump P-3 Library-3: Replace Workroom Lockset Library-4: Replace Boiler Thermostat Library-5: Weather-strip Exterior Doors Energy Savings (Estimated) ($50) ($20) ($50) High Priority Library-6a: Set Computers to Sleep Mode $0 ($300) ($300) Library-6b: Turn Off Inactive Computers $0 ($190) ($190) Library-7: Water Conserving Aerators $0 ($60) ($60) Library-8: Boiler Flue Damper ($190) $0 ($190) Medium Priority Library-9: Boiler Room Heat Recovery ($700) $280 ($420) Library-10: Retro-commission HVAC Systems ($740) ($50) ($790) Library-11: Replace Entrance Glazing ($180) $0 ($180) ECO Savings ($1,860) ($330) ($2,190) (20%) (4%) (12%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 93 Library Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational Library-1: Turn Off Equipment $0 Library-2: Interlock Pump P-3 $100 Library-3: Replace Workroom Lockset $200 Library-4: Replace Boiler Thermostat $200 Library-5: Weather-strip Exterior Doors $500 Totals $1,000 $0 ($1,800) ($800) High Priority Library-6a: Set Computers to Sleep Mode $200 $0 ($5,400) ($5,200) Library-6b: Turn Off Inactive Computers $200 $0 ($3,500) ($3,300) Library-7: Water Conserving Aerators $100 $0 ($1,200) ($1,100) Library-8: Boiler Flue Damper $2,000 $600 ($6,000) ($3,300) Medium Priority Library-9: Boiler Room Heat Recovery $11,000 $2,600 ($17,200) ($3,600) Library-10: Retro-commission HVAC Systems $19,600 $0 ($24,600) ($5,000) Library-11: Replace Entrance Glazing $4,900 $0 ($5,800) ($900) Totals $39,000 $3,200 ($65,400) ($23,200) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 94 Library ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic fuel oil consumption • Historic electricity use • Energy and life cycle cost analysis calculations 0 2,000 4,000 6,000 8,000 10,000 0 2,000 4,000 6,000 8,000 2003 2004 2005 2006 2007 2008 Degree DaysGallonsFuel Oil Consumption Gallons Degree Days Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Library ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND 2005 2006 2007 2008 kWh kWh kWh kWh Jan 8,515 8,086 7,845 9,045 33,491 Feb 7,738 7,827 8,844 8,714 33,123 Mar 7,620 7,659 7,667 9,832 32,778 Apr 6,400 7,650 8,736 10,848 33,634 May 6,899 9,203 7,270 7,352 30,724 Jun 6,833 7,466 7,385 8,348 30,032 Jul 6,466 8,563 6,703 7,909 29,641 Aug 8,164 8,122 7,618 7,882 31,786 Sep 7,242 7,766 7,939 7,853 30,800 Oct 8,015 8,793 7,458 7,430 31,696 Nov 8,049 8,047 7,912 8,291 32,299 D 8 308 8 438 8 465 7 984 33 195 August 8, 2009 General Service Month Average Dec 8,308 8,438 8,465 7,984 33,195 Total 90,249 97,620 93,842 101,488 95,800 Average 7,521 8,135 7,820 8,457 7,983 ELECTRIC BILLING DETAILS 2007 2008 Month Energy Energy Jan 734 842 14.8% Feb 824 813 -1.4% Mar 718 914 27.2% Apr 815 1,001 22.9% May 682 690 1.1% Jun 693 780 12.6% Jul 631 740 17.3% Aug 714 737 3.3% Sep 743 735 -1.0% Oct 699 697 -0.4% Nov 740 774 4.6% Dec 790 747 -5.5% Total $ 8,782 $ 9,468 7.8% Average $ 732 $ 789 7.8% Cost ($/kWh) $0.094 $0.093 % Change Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Library August 8, 2009 0 2,000 4,000 6,000 8,000 10,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 2,000 4,000 6,000 8,000 10,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 $ 0 $ 200 $ 400 $ 600 $ 800 $ 1,000 $ 1,200 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Library Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Library-1: Turn Off Equipment 1 job $0 $0 Library-2: Interlock Pump P-3 1 job $100 $100 Library-3: Replace Workroom Lockset 1 job $200 $200 Library-4: Replace Boiler Thermostat 1 job $200 $200 Library-5: Weather-strip Exterior Doors 1 job $500 $500 Energy Costs Electric Energy 1 - 25 -190 kWh $0.085 ($295) Fuel Oil 1 - 25 -20 gal $2.40 ($1,531) Net Present Worth ($826) Library-6a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 24 -125 12 12 -13,104 25% -3,276 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs August 8, 2009 kW -3.0 Year Year 0 0 0 0 0 Construction Costs Install aerator 1 job $200 $200 Energy Costs Electric Energy 1 - 25 -3,276 kWh $0.090 ($5,411) Net Present Worth ($5,211) Library-6b: Turn Off Inactive Computers Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 24 -20 12 12 -2,097 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 1 job $200 $200 Energy Costs Electric Energy 1 - 25 -2,097 kWh $0.090 ($3,463) Net Present Worth ($3,263) Year kW -0.5 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Library August 8, 2009 Library-7: Water Conserving Aerators Energy Analysis HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kWh Electric 2.5 0.5 15 -3,650 -714 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 2 ea $50 $100 Energy Costs Electric Energy 1 - 25 -714 kWh $0.090 ($1,179) Net Present Worth ($1,079) Library-8: Boiler Flue Damper Energy Analysis Input, gph FO Gallons On Hours Off Hours CFM w/damper kBTU Boiler Effic Fuel, gals 4.5 4,000 889 7,871 5 -7,359 70% -78 10%98% Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install flue damper 1 ea $2,000 $2,000 Annual Costs Flue damper maintenance 1 - 25 0.5 hr $60.00 $648 Energy Costs Fuel Oil 1 - 25 -78 gal $2.40 ($5,960) Net Present Worth ($3 312) Year 0 Use/Day 20 Year 0 10 CFM w/o damper Net Present Worth ($3,312) Library-9: Boiler Room Heat Recovery Energy Analysis Boiler MBH Factor Loss, MBH Factor kBTU Boiler Effic Fuel, gals CFM 606 1.3% 8 40% -27,605 70% -292 358 HP η, motor kW Hours 0.75 81.0% 0.7 4,500 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs 400 CFM heat recovery unit 1 ea $5,500 $5,500 Supply and return ductwork 1 ea $3,000 $3,000 Electric and controls 1 ea $2,500 $2,500 Annual Costs HRV maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 3,108 kWh $0.090 $5,134 Fuel Oil 1 - 25 -292 gal $2.40 ($22,355) Net Present Worth ($3,629) kWh 3,108 Year 0 0 Recovery, MBH -3 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Library August 8, 2009 Library-10: Retro-commission HVAC Systems Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Develop control sequences 1 ea $2,000 $2,000 Automatic control modifications 2 pts $1,500 $3,000 Retro-commissioning Modify control drawings 16 hrs $140 $2,240 Modify control software 16 hrs $140 $2,240 On-site Implementation and travel, including commissioning 32 hrs $140 $4,480 Perdiem and Travel 1 ea $2,500 $2,500 Closeout 8 hrs $140 $1,120 Verification 1 ea $2,000 $2,000 Energy Costs Electric Energy 1 - 25 -550 kWh $0.085 ($855) Fuel Oil 1 - 25 -310 gal $2.40 ($23,724) Net Present Worth ($5,000) Library-11: Replace Entrance Glazing Energy Analysis Room R,old R,new Area, sqft kBTU η, boiler Fuel, gals Entrance 0.7 2.0 44 -7,158 70% -76 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Rl id 44 f $112 $4 928 Year 0 Factor 0 0 0 0 0 0 0 100% Year 0 Replace entrance windows 44 sqft $112 $4,928 Energy Costs Fuel Oil 1 - 25 -76 gal $2.40 ($5,797) Net Present Worth ($869) Library-12: Install Ceiling Fans Energy Analysis Option Area Roof R-value Tosa kBTU Boiler Effic Fuel, gals Exist -3,300 18 41 -62,634 70% -663 Fans 3,300 18 41 46,574 70% 493 -170 Number watts kW Hours 4 75 0.3 4,400 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install ceiling fans 4 ea $750 $3,000 Controls 4 pts $1,500 $6,000 Electrical 4 ea $500 $2,000 Energy Costs Electric Energy 1 - 25 1,320 kWh $0.090 $2,180 Fuel Oil 1 - 25 -170 gal $2.40 ($13,006) Net Present Worth $174 0 Trm 80 0 0 70 kWh 1,320 Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Library August 8, 2009 Library-13: Upgrade HVAC Motors Energy Analysis Unit HP η, old η, new Hours ΔkWh AHU-1 3 86.5% 89.5% 4,108 -356 AHU-2 2 83% 86.5% 4,108 -299 -655 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace 2 HP motor 1 ea $620 $620 Replace 3 HP motor 1 ea $670 $670 Energy Costs Electric Energy 1 - 25 -655 kWh $0.090 ($1,082) Net Present Worth $208 ΔkW -0.09 0 0 -0.07 -2 Year Alaska Energy Engineering LLC CBS Energy Audit 95 Public Services Office/Shop Section 7 Public Services Office/Shop Building INTRODUCTION The Public Services Office/Shop building contains office spaces, meeting rooms, and various shops associated with the public works department. The building characteristics are: • Size: 20,440 square feet • Occupied Hours: Monday-Friday 6:00 am to 6:00 pm • Occupancy: Fully occupied Monday-Friday 8:00 am to 5:00 pm; Some people arrive at 6:00 am and others stay until 6:00 pm. • HVAC Hours: Monday-Friday 6:00 am to 6:00 pm • Heating and Ventilating Systems: Several central air handling unit with constant airflow and duct heating coils supply the building. Perimeter baseboard heaters or in-floor heating slabs supply heat. • Domestic Hot Water System: Electric hot water heater ENERGY CONSUMPTION AND COST The building energy sources are electricity, fuel oil, and an insignificant amount of used oil. Fuel oil and used oil is consumed by the boilers for heat and domestic hot water and electricity supplies all other loads. The following table summarizes the energy consumption and cost. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Fuel Oil 8,100 gals $19,400 1,100 (85%) Electricity 54,000 kWh $5,400 200 (15%) Totals - $24,800 1,300 (100%) Electrical consumption is the average from 2005-2008. Fuel oil consumption is the average from 2003-2008. Costs are based on 2009 prices. Trends Fuel Oil: Fuel oil use has varied from year-to-year over the previous four years. There is no clear explanation for the variation. Electricity: Electricity use was steady from 2005 to 2008. Electric demand was steady at 22 kW from 2005-2008. Effective cost—energy plus demand charges—is 9.6¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 9.0¢ per kWh. Electrical energy is much lower than the 33% typical of office buildings. The reason is likely that much of the building is shop/warehouse space that has lower electrical use than an office. Energy consumption data is located at the end of this section. Alaska Energy Engineering LLC CBS Energy Audit 96 Public Services Office/Shop DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Interior wallboard; metal girts w/ R-19 batt; metal siding R-12 Roof Metal girts w/ R-19 batt; metal roofing R-12 Floor Slab Non-radiant Concrete slab-on-grade R-2 Radiant Concrete slab-on-grade, 1-1/2” rigid R-8 Perimeter Concrete footing R-2 Windows Vinyl fame; double pane, low-e, argon filled glazing; good weather-stripping R-2.3 Doors Entrance Metal frame w/o thermal break; double pane glazing; poor weather-stripping R-2.0 Overhead Insulated metal door w/ thermal break; good weather -stripping R-3.0 Analysis Walls: The wall insulation is below optimal insulation levels of R-25-30. The metal girts do not have a thermal break from outside to inside. There is no cost effective way of adding a thermal break to the walls. Roof: The roof insulation is below optimal insulation levels of R-50 to R-60. The metal girts do not have a thermal break from outside to inside. There is no cost effective way of adding a thermal break to the roof. Floor Slab: The lack of non-radiant floor slab insulation is below optimal insulation levels of R-5 to R-10. Lack of insulation is typical of past practice and there is no economical way to add insulation to the floor slabs. Perimeter: The lack of perimeter insulation is below optimal insulation levels of R-10 to R-15. Windows: The window thermal properties are below optimal triple pane vinyl windows. Doors: Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non- thermally broken frames. Other Items: • The electric department entrance does not have an arctic entrance to minimize infiltration. • The effectiveness of the line crew arctic entrance is compromised because the inner door is held open. Heating System Description The heating system consists of a used oil-fired hot water boiler (B-1), an oil-fired, hot water boiler (B-2), and a hydronic distribution system with constant speed pumps supplying heating water to the building. Alaska Energy Engineering LLC CBS Energy Audit 97 Public Services Office/Shop The heating units consist of ventilation heating coils, unit heaters, and baseboard heaters. Four radiant heating loops supply in-floor heating zones. This system has been turned off. The heating system has the following pumps: • Pump CP-1 and CP-2: Primary heating pumps • Pump CP-4: Radiant loop • Pump CP-5: Radiant loop • Pump CP-6: Radiant loop • Pump CP-7: Radiant loop Analysis The boilers are operated in a lead/standby configuration year-round. The used oil boiler is operated three days per month. The operating thermostat has a fixed on-off temperature differential of 10°F. A larger differential will decrease cycling losses and improve seasonal efficiency. The boilers do not have flue dampers to minimize the flow of heated air through the boiler and up the chimney when it is not operating. Converting to a primary/secondary pumping with variable speed pumping will decrease pumping costs by allowing pump energy consumption to vary with the heating load. The unit heaters and cabinet unit heaters do not have automatic valves to shut off the heating water flow when heat is not required. Heating units are not interlocked to turn off when overhead doors are open. Ventilation System Description Air Handling Unit AHU-1 and Return Fan RF-1: AHU-1 is an air handling unit that supplies constant flow mixed air to the offices. The unit has a mixing box, filter section, heating coil, and supply fan. Return air from the rooms is drawn through the ceiling plenum to RF-1 where it is returned to AHU-1 or exhausted from the building. Air Handling Unit AHU-2: AHU-2 is an air handling unit that supplies constant flow mixed air to the wood shop. The unit has a mixing box, filter section, heating coil, and supply fan. Air Handling Unit AHU-3 and Exhaust Fan EF-5: AHU-3 is an air handling unit that supplies constant makeup air flow to the vehicle shop. The unit has a filter section, heating coil, and supply fan. EF-5 is a utility fan serving the vehicle exhaust system. Air Handling Unit AHU-4 and Exhaust Fan EF-9: AHU-4 is an air handling unit that supplies constant makeup air flow to the welding shop. The unit has a filter section, heating coil, and supply fan. EF-9 is a utility fan serving the welding exhaust hood. Air Handling Unit AHU-5 and Exhaust Fan EF-12: AHU-5 is an air handling unit that supplies constant makeup air flow to the paint booth. The unit has a filter section, heating coil, and supply fan. EF-12 is an in-line fan serving the paint booth. Air Handling Unit AHU-6: AHU-6 is an air handling unit that supplies constant flow mixed air to the shop area. The unit has a mixing box, filter section, heating coil, and supply fan. Alaska Energy Engineering LLC CBS Energy Audit 98 Public Services Office/Shop Exhaust Fan EF-1: EF-1 is a utility exhaust fan that draws exhaust air from the toilet rooms. Exhaust Fan EF-2: EF-2 is a utility exhaust fan that draws exhaust air from the toilet/janitor room. Exhaust Fan EF-3: EF-3 is a ceiling exhaust fan that draws exhaust air from the women’s toilet. Exhaust Fan EF-4: EF-4 is a ceiling exhaust fan that draws exhaust air from the men’s toilet. Exhaust Fan EF-6: EF-2 is a utility exhaust fan that draws exhaust air from the vehicle shop. Exhaust Fan EF-7: EF-7 is an inline propeller fan drawing exhaust air form the vehicle shop when carbon monoxide levels are too high. Exhaust Fan EF-11: EF-11 is a utility exhaust fan that draws exhaust air from the building maintenance shop. Analysis Air Handling Unit AHU-1 and Return Fan RF-1: • The motors are not energy efficient. • Converting to a variable air flow system will be more energy efficient. Air Handling Unit AHU-2: • AHU-2 is not used. • The heating coil should be isolated and drained to prevent freezing. • Insulation on the outside air duct is loose. • The louvers should be sealed off. Air Handling Unit AHU-3 and Exhaust Fan EF-5: • Insulation is missing on the outside air duct. • The motors are not energy efficient. Air Handling Unit AHU-4 and Exhaust Fan EF-9: The motors are not energy efficient. Air Handling Unit AHU-5 and Exhaust Fan EF-12: The motors are not energy efficient. Air Handling Unit AHU-6: • AHU-6 is not used. • The heating coil should be isolated and drained to prevent freezing. • The outside air damper does not close tightly. • The louvers should be sealed off. Exhaust Fan EF-7: The motors are not energy efficient. Exhaust Fan EF-11: • EF-11 is not used. • The louver should be sealed off. There is no boiler room heat recovery. The ductwork is not sealed. Alaska Energy Engineering LLC CBS Energy Audit 99 Public Services Office/Shop Domestic Hot Water System Description An electric hot water heater supplies domestic hot water to the building. Hot water recirculating pump CP-3 maintains hot water in the distribution piping. The lavatory faucet aerators have a flow rate of 2.5 gpm. The faucets are not auto-sensing. Analysis Ultra-low aerators of 0.5 gpm are available for lavatory faucets. Automatic Control System Description The building HVAC systems are controlled by local controllers and a Honeywell DDC control system that interfaces with the City’s community-wide Honeywell system. Basic Control Sequences Boilers B-1 and B-2: Manually operated in a lead/standby configuration. Boilers are disabled when outdoor temperature is above 65°F. When boiler B-1 (used oil) is enabled, it operates through its internal controls. When boiler B-2 is enabled, its operating thermostat turns the burner on at 160°F and off at 170°F. Pumps CP-1 and CP-2: Operate in a lead/standby configuration with automatic switchover. Pumps CP-4, CP-5, CP-6, and CP-7: • Operates in accordance with an occupied/unoccupied schedule • Pump is operated by Tekmar controller to maintain the room temperature setpoint • The radiant heating systems have been turned off Air Handling Unit AHU-1 and Return Fan RF-1: • Operates in accordance with an occupied/unoccupied schedule • Mixing dampers and heating coil automatic valve modulate to maintain the discharge temperature setpoint Air Handling Unit AHU-2: Not in use. Air Handling Unit AHU-3 and Exhaust Fan EF-5: • Manually operated to capture vehicle exhaust and provide makeup • Heating coil automatic valve modulates to maintain the room temperature setpoint Air Handling Unit AHU-4 and Exhaust Fan EF-9: • Manually operated to exhaust welding hood • Heating coil automatic valve modulates to maintain the room temperature setpoint Air Handling Unit AHU-5 and Exhaust Fan EF-12: • Manually operated to exhaust paint booth • Heating coil automatic valve modulates to maintain the room temperature setpoint Alaska Energy Engineering LLC CBS Energy Audit 100 Public Services Office/Shop Air Handling Unit AHU-6: Not in use. Exhaust Fan EF-1: Operates in accordance with an occupied/unoccupied schedule Exhaust Fan EF-2: Operates continuously Exhaust Fan EF-3: Manually operated Exhaust Fan EF-4: Manually operated Exhaust Fan EF-6: Operates continuously Exhaust Fan EF-7: Operates when carbon monoxide levels exceed 35 ppm or nitrogen dioxide level exceeds 1 ppm. Exhaust Fan EF-11: Not in use. Pump CP-3: Operates continuously Analysis AHU-1: The controls do not modulate ventilation air with occupancy. Exhaust Fans EF-3 and EF-4: The toilet room light and the EF are on the same switch. The fan is operated continuously during occupied hours, causing the light to remain on as well. Lighting Description The interior and exterior lighting is energy efficient. Analysis There are no occupancy sensors to control lighting. Interior lighting was found to be on when rooms are unoccupied. Turning of the lighting saves energy and increases lamp life. Electric Equipment Description The building has 23 computers that are left on continuously. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. Alaska Energy Engineering LLC CBS Energy Audit 101 Public Services Office/Shop ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. PSC-1: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Lighting was left on in unoccupied rooms. Scope: Turning off lighting is an ECO with immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. This ECO requires behavior changes where occupants regularly turn off lighting rather than leave it on. Analysis: This ECO is recommended without analysis. PSC-2: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment is an ECO with immediate payback. This ECO requires behavior changes where occupants regularly turn off equipment when they are finished with it. Analysis: This ECO is recommended without analysis. PSC-3: Close Inner Entrance Doors Purpose: Heat will be saved if the inner door of the line crew entrance is closed so that the entrance functions as an arctic entrance. Scope: Close the inner entrance door during the primary heating season of September 1 to May 1. It is assumed that an ADA operator is not needed on these doors because the primary entrance is handicap accessible. Analysis: This is ECO is recommended without analysis. PSC-4: Reduce Entrance Temperatures Purpose: Heat will be saved by reducing the temperature setpoints of entrance heaters. The heaters are located near building entrances to minimize the thermal comfort impacts of cold air entering the building and to dry the floor. The higher the temperature at the entrance the greater the amount of heat loss to outdoors, whether the doors are open or closed. Reducing the temperature setpoint to the minimum needed for thermal comfort and moisture control will reduce heat loss. Scope: Turn entrance setpoints down to 55°F and determine if this is adequate for thermal comfort and moisture control. Adjust as needed. Mark the desired setpoint on the thermostat so it can be visually verified. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 102 Public Services Office/Shop PSC-5: Replace Boiler Thermostat Purpose: Fuel oil will be saved if the boiler operates with longer run cycles. The boiler operating thermostat has a fixed 10°F differential between on and off setpoints. A new controller that allows a 30°F differential will increase the amount of time the boiler operates during each cycle, which will improve seasonal efficiency. Scope: The thermostat was replaced in July, 2009 with a model that has an adjustable temperature differential of 20-40°F. Set the differential as great as possible. As a starting point, use typical differentials of 30°F in the winter and 40°F in the summer. Analysis: This ECO is recommended without analysis. PSC-6: Decommission Ventilation Systems (AHU-2, AHU-6, EF-11) Purpose: Heat will be saved if HVAC systems that are no longer in use are decommissioned. Scope: Decommission HVAC systems that are no longer use. Analysis: This ECO is recommended without analysis. PSC-7: Repair Duct Insulation (AHU-2, AHU-3, EF-1, EF-9) Purpose: Heat will be saved if duct insulation is repaired on AHU-2, AHU-3, EF-1 and EF-9. Scope: Repair the duct insulation on AHU-2, AHU-3, EF-1 and EF-9 Analysis: This ECO is recommended without analysis. PSC-8: Weather-Strip Exterior Doors Purpose: Heat will be saved if doors are properly weather-stripped to reduce infiltration. The exterior corridor doors do not have adequate weather-stripping. Scope: Install or repair the weather-stripping on all exterior doors. Analysis: This ECO is recommended without analysis. PSC-9: Interlock Heaters with Overhead Doors Purpose: Heat will be saved if the heating units turn off automatically when the overhead doors are open. Scope: Install limit switches on each automatic door that turns off the heating units when the door is open. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 103 Public Services Office/Shop High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. PSC-10: Install Water-Conserving Aerators Purpose: Fuel oil will be saved by using water-conserving aerators on sinks and lavatories. Scope: Replace lavatory aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 60 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual electricity use by 1,500 kWh and energy costs by $140. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 $0 ($2,500) ($2,300) Note: Negative numbers, in parenthesis, represent savings. PSC-11: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Analysis: The PSC has 23 computers. The analysis assumes that the computers are not in use for 15 hours of the day. The power settings were not checked on each machine, so the following analysis assumes that 25% of the computers are not set to enter sleep mode when inactive. Setting the power settings from screen saver to sleep mode will reduce annual electricity use by 4,600 kWh and energy costs by $420. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 2,900 kWh and energy costs by $270. The following table summarizes the life cycle cost analysis. Alaska Energy Engineering LLC CBS Energy Audit 104 Public Services Office/Shop Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $500 $0 ($7,600) ($7,100) Turn Off $500 $0 ($4,900) ($4,400) Total $1,000 $0 ($12,500) ($11,500) Note: Negative numbers, in parenthesis, represent savings. Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. PSC-12: Install Unit Heater Automatic Valve Purpose: Fuel oil will be saved if each unit heater has an automatic valve that shuts off the hydronic heating flow when heat is not needed. The heater coil is continuously hot which results in convective heat loss when the heater fan is not operating. While some of the heat loss may be useful, it is often not. Scope: Install an automatic valve on each unit heater to shut off the hydronic heating flow when heat is not needed. Analysis: This ECO will reduce annual fuel oil use by 280 gallons and energy costs by $670. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,000 $0 ($21,300) ($15,300) Note: Negative numbers, in parenthesis, represent savings. PSC-13: Install Boiler Room Heat Recovery Purpose: Heat will be saved if heat from the boiler room is recovered and transferred to the wood shop. Scope: Install a heat recovery unit in the boiler room. Install ductwork to circulate boiler room air through one side of the heat recovery cell. Install ductwork to supply the heated air to the wood shop and return it. Analysis: The analysis assumes that the boiler loses 2% to jacket losses. The HRU is assumed to recover 67% of the heat loss. This ECO will reduce annual fuel oil use by 500 gallons and increase electricity use by 3,000 kWh to operate the fans, with a net energy savings of $870. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $16,500 $2,600 ($32,100) ($13,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 105 Public Services Office/Shop PSC-14: Install Boiler Flue Damper Purpose: Heat will be saved by installing a flue damper in the boiler chimney to minimize the flow of heated air through the boiler and up the chimney. Scope: Install a damper in each boiler flue and control it to open prior to firing the boiler. Analysis: This ECO will improve the boiler seasonal efficiency by a minimum of 1.5% and reduce annual fuel oil use by 150 gallons and energy costs by $360. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,000 $1,300 ($11,500) ($4,200) Note: Negative numbers, in parenthesis, represent savings. PSC-15: Retro-commission Building Purpose: Fuel and electricity will be saved if the building energy systems are optimized through a retro-commissioning process. The energy audit revealed that the building operating sequences are not optimal. Scope: Retro-commission the building with a focus on the following: − Optimize automatic control strategies − Reduce minimum outside air flow − Optimize demand controlled ventilation (CO2 sensors) − Utilize scheduled ventilation − Utilize supply air reset control − Occupancy sensor control − Temperature setback of unoccupied rooms Analysis: The analysis conservatively assumes that retro-commissioning will reduce fuel oil use by 6% and electricity use by 1% This ECO will reduce annual electricity use by 540 kWh, fuel oil use by 480 gallons and energy costs by $1,200.The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $25,400 $0 ($37,600) ($12,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 106 Public Services Office/Shop PSC-16: Install Lighting Occupancy Sensors Purpose: Electricity use will be reduced by installing occupancy sensor that will automatically turn the lighting off when rooms are unoccupied. Scope: Install occupancy sensors in offices, conference rooms, workrooms, and toilet rooms. Analysis: The analysis assumes that office and toilet room lighting will, on an average, be off three and six hours per day, respectively. This ECO will reduce annual electricity use by 5,700 kWh and energy costs by $480. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,500 $1,300 ($8,800) ($1,000) Note: Negative numbers, in parenthesis, represent savings. Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. PSC-17: Convert to Variable Speed Hydronic Pumping Purpose: Electricity will be saved if the hydronic heating system is converted to variable flow pumping. Scope: Install VFDs and NEMA Premium® motors on pumps CP-1 and CP-2. Analysis: The analysis assumes that the average flow rate will be 33% of the peak flow rate. This ECO will reduce annual electricity use by 6,800 kWh, electric demand by 6 kW, and energy costs by $640. However, the cost to upgrade two pumps to variable speed is not offset by lower energy costs. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $12,700 $2,600 ($11,800) $3,500 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 107 Public Services Office/Shop PSC-18: Replace HVAC Motors Purpose: Electricity will be saved if less efficient motors are upgraded to NEMA Premium® motors. Scope: Replace the motors for CP-1, CP-2, and AHU-1with NEMA Premium® motors. Analysis: This ECO will reduce annual electricity use by 780 kWh, electric demand by 2 kW, and energy costs by $70. The existing motor efficiencies are only slightly lower than NEMA efficiency, so energy savings is unable to offset the replacement cost. This ECO is not recommended. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $2,000 $0 ($1,300) $700 Note: Negative numbers, in parenthesis, represent savings. PSC-19: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand is very steady so there is little need to educate people on demand control. PSC-20: Add Arctic Entrance Purpose: Heat will be saved if the electric department entrance is converted to an arctic entrance. Analysis: Arctic entrances require people to pass through two doors to enter/leave the building. With sufficient distance between them, one door closes before the other opens, sealing the entrance and reducing infiltration. The life cycle energy savings will be insufficient to offset the high cost of constructing the arctic entrance in an existing building and installing an ADA operator. This ECO is not recommended. PSC-21: Increase Wall Insulation Purpose: Fuel oil will be saved by adding insulation to the walls. Analysis: It is difficult and costly to add insulation to the walls structure. Exterior insulation will require costly removal and replacement of the metal siding. Interior insulation will require costly removal of interior finishes and wallboard. Previous analyses have shown that adding insulation will not provide a life cycle savings. This ECO is not recommended. PSC-22: Increase Roof Insulation Purpose: Fuel oil will be saved by adding insulation to the roof. Analysis: It is difficult and costly to add insulation to the roof structure. In addition, the metal structure has thermal bridging that reduces the effectiveness of additional insulation. Previous analyses have shown that adding insulation will not provide a life cycle savings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 108 Public Services Office/Shop PSC-23: Replace Windows Purpose: Heat will be saved if the double pane windows are replaced with triple pane windows. Analysis: Triple pane windows can improve the R-value by 100%, from R-2.3 to R-4.8. Previous analyses have shown that the cost of labor to replace the windows is not offset by energy savings. This ECO is not recommended. PSC-24: Convert to Variable Air Flow (AHU-1) Purpose: Fuel oil and electricity will be saved by converting AHU-1 from constant flow to variable. Analysis: AHU-1 is a small system, which limits the energy savings potential of a VAV system. It is possible that if AHU-1 were originally constructed as a VAV system, it would have provided a life cycle savings. Converting the system will have too high a cost to provide a life cycle savings. This ECO is not recommended. PSC-25: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of the high cost of accessing existing ducts above ceilings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 109 Public Services Office/Shop SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Fuel Oil Electricity Total Current Energy Costs $19,400 $5,400 $24,800 Behavioral and Operational PSC-1: Turn Off Lighting PSC-2: Turn Off Equipment PSC-3: Close Inner Entrance Doors PSC-4: Reduce Entrance Temperature PSC-5: Replace Boiler Thermostat PSC-6: Decommission Ventilation Systems PSC-7: Repair Duct Insulation PSC-8: Weather-strip Exterior Doors PSC-9: Interlock Heaters with Overhead Doors Energy Savings (Estimated) ($190) $0 ($190) High Priority PSC-10: Water Conserving Aerators $0 ($140) ($140) PSC-11a: Set Computers to Sleep Mode $0 ($420) ($420) PSC-11b: Turn Off Inactive Computers $0 ($270) ($270) Medium Priority PSC-12: Unit Heater Automatic Valves ($670) $0 ($670) PSC-13: Install Boiler Room Heat Recovery ($1,200) $330 ($870) PSC-14: Install Boiler Flue Damper ($360) $0 ($360) PSC-15: Retro-commission HVAC Systems ($1,150) ($50) ($1,200) PSC-16: Install Lighting Occupancy Sensors $0 ($480) ($480) ECO Savings ($3,570) ($1,030) ($4,600) (18%) (19%) (19%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 110 Public Services Office/Shop Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational PSC-1: Turn Off Lighting $0 PSC-2: Turn Off Equipment $0 PSC-3: Close Inner Entrance Doors $0 PSC-4: Reduce Entrance Temperature $100 PSC-5: Replace Boiler Thermostat $200 PSC-6: Decommission Ventilation Systems $500 PSC-7: Repair Duct Insulation $500 PSC-8: Weather-strip Exterior Doors $800 PSC-9: Interlock Heaters with Overhead Doors $2,500 Totals $4,600 $0 ($6,200) ($1,600) High Priority PSC-10: Water Conserving Aerators $200 $0 ($2,500) ($2,300) PSC-11a: Set Computers to Sleep Mode $500 $0 ($7,600) ($7,100) PSC-11b: Turn Off Inactive Computers $500 $0 ($4,900) ($4,400) Medium Priority PSC-12: Unit Heater Automatic Valves $6,000 $0 ($21,300) ($15,300) PSC-13: Install Boiler Room Heat Recovery $16,500 $2,600 ($32,100) ($13,000) PSC-14: Install Boiler Flue Damper $6,000 $1,300 ($11,400) ($4,100) PSC-15: Retro-commission HVAC Systems $25,400 $0 ($37,600) ($12,100) PSC-16: Install Lighting Occupancy Sensors $6,500 $1,300 ($8,800) ($1,000) Totals $66,200 $5,200 ($132,400) ($61,000) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 111 Public Services Office/Shop ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic fuel oil consumption • Historic electricity use • Energy and life cycle cost analysis calculations 0 2,000 4,000 6,000 8,000 10,000 0 2,000 4,000 6,000 8,000 10,000 2003 2004 2005 2006 2007 2008 Degree DaysGallonsFuel Oil Consumption Gallons Degree Days Alaska Energy Engineering LLC CBS Energy Audit 112 Public Services Office/Shop This page intentionally left blank Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Complex - Offices ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 3,760 23 4,080 19 4,480 21 5,360 22 17,680 Feb 4,640 22 4,880 19 4,800 23 5,440 23 19,760 Mar 4,960 22 3,840 21 4,480 21 4,720 22 18,000 Apr 4,400 21 4,080 21 4,400 21 5,040 21 17,920 May 4,320 22 3,920 19 4,720 22 4,400 24 17,360 Jun 4,880 21 4,320 18 4,720 21 4,320 19 18,240 Jul 4,160 20 3,760 19 4,720 20 4,800 25 17,440 Aug 4,320 18 4,240 21 4,720 20 4,800 20 18,080 Sep 4,960 21 4,080 22 4,640 23 4,480 21 18,160 Oct 4,400 22 4,160 23 4,960 20 4,160 21 17,680 Nov 4,800 21 4,560 21 4,400 24 4,560 21 18,320 D 4 560 23 4 640 25 4 240 25 4 720 20 18 160 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 4,560 23 4,640 25 4,240 25 4,720 20 18,160 Total 54,160 50,560 55,280 56,800 54,200 Average 4,513 21 4,213 21 4,607 22 4,733 22 4,517 Load Factor 29.1% 28.0% 29.0% 30.1% 21 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 430 0 430 510 0 510 18.5% Feb 459 0 459 517 0 517 12.6% Mar 430 0 430 452 0 452 5.0% Apr 423 0 423 481 0 481 13.7% May 452 0 452 423 0 423 -6.4% Jun 452 0 452 416 0 416 -8.0% Jul 452 0 452 459 0 459 1.6% Aug 452 0 452 459 0 459 1.6% Sep 445 0 445 430 0 430 -3.2% Oct 474 0 474 401 0 401 -15.3% Nov 423 0 423 437 0 437 3.4% Dec 409 0 409 452 0 452 10.6% Total $ 5,300 $ 0 $ 5,300 $ 5,437 $ 0 $ 5,437 2.6% Average $ 442 $ 0 $ 442 $ 453 $ 0 $ 453 2.6% Cost ($/kWh) 0.0959 100% 0% 0.0957 -0.2% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Complex - Offices August 8, 2009 0 1,000 2,000 3,000 4,000 5,000 6,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 1,000 2,000 3,000 4,000 5,000 6,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 5 10 15 20 25 30 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Complex - Offices August 8, 2009 $ 0 $ 100 $ 200 $ 300 $ 400 $ 500 $ 600 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 100 $ 200 $ 300 $ 400 $ 500 $ 600 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 0 5 10 15 20 25 30 0 1,000 2,000 3,000 4,000 5,000 6,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Center Office/Shop Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Qty Unit Base Cost Year 0 Cost Construction Costs PSC-1: Turn Off Lighting 1 job $0 $0 PSC-2: Turn Off Equipment 1 job $0 $0 PSC-3: Close Inner Entrance Doors 1 job $0 $0 PSC-4: Reduce Entrance Temperature 1 job $100 $100 PSC-5: Replace Boiler Thermostat 1 job $200 $200 PSC-6: Decommission Ventilation Systems 1 job $500 $500 PSC-7: Repair Duct Insulation 0 1 job $500 $500 PSC-8: Weather-strip Exterior Doors 1 job $800 $800 PSC-9: Interlock Heaters with Overhead Doors 6 ea $417 $2,500 Energy Costs Electric Energy 1 - 25 -30 kWh $0.085 ($47) Fuel Oil 1 - 25 -80 gal $2.40 ($6,122) Net Present Worth ($1,569) PSC-10: Water Conserving Aerators Energy Analysis HW Heater Exist GPM New GPM Duration sec Gal saved Heat kBTU kWh August 8, 2009 Year 0 0 0 Use/Day 0 0 0 0 0 HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kBTU kWh Electric 2.5 0.5 15 -7,800 -5,204 -1,525 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 6 ea $33 $200 Energy Costs Electric Energy 1 - 25 -1,525 kWh $0.0903 ($2,518) Net Present Worth ($2,319) PSC-11a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 23 -125 15 24 -18,389 25% -4,597 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Modify computer power settings 1 ea $500 $500 Energy Costs Electric Energy 1 - 25 -4,597 kWh $0.0903 ($7,593) Net Present Worth ($7,093) kW -2.9 Use/Day 60 Year 0 0 Year Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Center Office/Shop August 8, 2009 PSC-11b: Turn Off Inactive Computers Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 23 -20 15 24 -2,942 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Modify computer power settings 1 ea $500 $500 Energy Costs Electric Energy 1 - 25 -2,942 kWh $0.0903 ($4,859) Net Present Worth ($4,359) PSC-12: Unit Heater Automatic Valves Energy Analysis Loss, BTUH Number Factor Loss, kBTU Fuel, gals 1,000 15 20% -26,280 -278 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install AV and controls 15 ea $400 $6,000 Energy Costs Fuel Oil 1 - 25 -278 gal $2.40 ($21,283) Net Present Worth ($15,283) PSC-13: Install Boiler Room Heat Recovery Year 0 70% 0 Year kW -0.5 Boiler Effic Energy Analysis Boiler MBH Factor Loss, MBH Factor kBTU Boiler Effic Fuel, gals CFM 899 1.5% 13 40% -47,242 70% -500 613 HP η, motor kW Hours 1.0 81.0% 0.9 3,500 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs 700 CFM heat recovery unit 1 ea $7,500 $7,500 Supply and return ductwork 1 ea $6,000 $6,000 Electric and controls 1 ea $3,000 $3,000 Annual Costs HRV maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 3,223 kWh $0.0903 $5,324 Electric Demand 1 - 25 11 kW $3.90 $788 Fuel Oil 1 - 25 -500 gal $2.40 ($38,259) Net Present Worth ($13,054) -5 kWh 3,223 Year 0 0 0 Recovery, MBH Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Center Office/Shop August 8, 2009 PSC-14: Install Boiler Flue Damper Energy Analysis Input, gph FO Gallons On Hours Off Hours CFM w/damper kBTU Boiler Effic Fuel, gals 6.7 8,000 1,201 7,559 5 -14,135 70% -150 14%98.1% Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install flue damper 2 ea $3,000 $6,000 Annual Costs Flue damper maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Fuel Oil 1 - 25 -150 gal $2.40 ($11,447) Net Present Worth ($4,151) PSC-15: Retro-commission HVAC Systems Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Develop control sequences 1 ea $3,000 $3,000 Automatic control modifications 2 pts $1,500 $3,000 Retro-commissioning Modify control drawings 32 hrs $140 $4,480 Modify control software 16 hrs $140 $2,240 On-site Implementation and travel, including commissioning 40 hrs $140 $5,600 Perdiem and Travel 1 ea $2 500 $2 500 0 0 Year CFM w/o damper Year 0 15 0 0 0 0Perdiem and Travel 1 ea $2,500 $2,500 Closeout 8 hrs $140 $1,120 Verification 1 ea $3,500 $3,500 Energy Costs Electric Energy 1 - 25 -540 kWh $0.085 ($840) Fuel Oil 1 - 25 -480 gal $2.40 ($36,735) Net Present Worth ($12,134) PSC-16: Install Lighting Occupancy Sensors Energy Analysis Room Number Area, sqft watts/sqft kWh Office 16 4,560 1.4 -4,980 Toilets 4 500 0.9 -702 Savings -5,682 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install occupancy sensor 20 ea $325 $6,500 Annual Costs Occupancy sensor maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Electric Energy 1 - 25 -5,682 kWh $0.085 ($8,833) Net Present Worth ($1,037) 0 ΔHours/Day 0 0 0 -3 -6 Year Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Public Services Center Office/Shop August 8, 2009 PSC-17: Convert to Variable Speed Pumping Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh P-1/2 -85 30 60% 84.0% -1.0 8,760 -8,358 P-1/2 w/VFD 30 18 68% 86.5% 0.2 8,760 1,517 Savings -6.2 -6,841 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs VFD + Integration 2 ea $4,500 $9,000 NEMA Premium motors 2 ea $590 $1,180 DDC integration 1 ea $2,500 $2,500 Annual Costs VFD maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 -6,841 kWh $0.0903 ($11,300) Electric Demand 1 - 25 -6 kW $3.90 ($446) Net Present Worth $3,527 PSC-18: Replace HVAC Motors Energy Analysis Unit HP η, old η, new Hours ΔkWh CP-1/CP-2 1.5 84% 86.5% 8,760 -337 AHU-1 5 88% 89.5% 4,628 -441 Year 0 -1.1 0 0 -0.04 -0.10 ΔkW 0.2 BHP -778 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace 1-1/2 HP motor 2 ea $585 $1,170 Replace 3 HP motor 1 ea $820 $820 Energy Costs Electric Energy 1 - 25 -778 kWh $0.085 ($1,210) Electric Demand 1 - 25 -2 kW $3.90 ($115) Net Present Worth $666 0 -2 Year 0 Alaska Energy Engineering LLC CBS Energy Audit 113 Senior Center Section 8 Senior Center INTRODUCTION The Senior Center contains a dining room, administrative spaces, and a commercial kitchen for preparing meals. The building characteristics are: • Size: 4,100 square feet • Occupied Hours: − Senior Van Staff: Operates out of the building Monday to Friday from 7:00 am to 6:00 pm − Senior Yoga Classes: Monday to Friday 7:00 am to 8:00 am − Administrative Staff: Monday to Friday 8:00 am to 5:00 pm − Cooking Staff: Monday to Friday 8:00 am to 2:00 pm − Seniors: Monday to Friday 10:30 am to 12:00 noon − Weekends: Community use averages 4 hours per week • Occupancy: Monday to Friday - Sixty-three lunches with 35 served on-site • HVAC Hours: Monday-Friday 10:00 am to 1:00 pm plus event hours • Heating and Ventilating Systems: Central air handling unit with constant airflow and electric heating coil supplies the building. Kitchen makeup fan and hood. Electric baseboard heaters. • Domestic Hot Water System: Electric hot water heater ENERGY CONSUMPTION AND COST The Senior Center is an all-electric building. The following table summarizes the energy consumption and cost. Electricity use spreadsheets and graphs are at the end of this section. Energy Consumption and Cost Source Consumption Cost Electricity 140,000 kWh $14,000 Consumption is the average from 2005-2008. Costs are based on 2009 prices. Trends Electricity: The monthly use pattern is typical of an electrically heated building. Consumption is much higher during the heating months and tapers gradually to baseline loads during the summer. Demand stays relatively steady throughout the year, which indicates that the heating units do not modulate. Consumption increased greatly in 2008 with more meal preparation and more community use. Effective cost—energy plus demand charges—is 10.3¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 8.5¢ per kWh. Energy consumption data is located at the end of this section. Alaska Energy Engineering LLC CBS Energy Audit 114 Senior Center DESCRIPTION OF SYSTEMS Envelope Building Envelope Component Description (inside to outside) R-value Walls Gypsum board; 2x6 wood studs; R-19 batt; sheathing; wood siding R-18 Roof Gypsum board; roof trusses with R-38 batt insulation in attic R-39 Floor Plywood subfloor; 20” TJI joists with R-38 batt; R-39 Crawlspace No vapor barrier - Windows Original Wood frame; double pane; good weather-stripping R-2.3 Dining Room Vinyl frame; double pane; good weather-stripping R-2.0 Doors Original Metal door w/o thermal break; double pane glazing; poor weather-stripping R-1.5 Entrance Metal frame w/o thermal break; single pane glazing; poor weather-stripping R-0.5 Analysis Walls: The wall insulation is below optimal levels of R-25-30. Adding insulation to existing walls does not provide a life cycle savings due to the high cost of replacing interior or exterior surfaces. When the siding is replaced, an investment in additional insulation will provide a life cycle energy savings. Roof: The roof insulation is below optimal insulation levels of R-50 to R-60. The investigation also revealed that the attic insulation is not uniformly placed. Floor: The floor insulation level is within optimal range of R-30 to R-40. Windows: None of the windows is optimally insulated. Typically, replacing double pane windows does not offer a life cycle savings. Good weather-stripping that minimizes infiltration is essential to thermal performance. Doors: Metal frames without thermal breaks have a lifetime energy penalty due to direct conduction of heat from inside to outside. The high cost of replacement offers little incentive to replace the non- thermally broken frames. Good weather-stripping that minimizes infiltration is essential to thermal performance. Other: • The interior arctic entrance door is being held open. Heating System Description The building is heated by electric heating coils in the air handling unit and electric baseboard heaters. Ventilation System Description Air Handling Unit AHU-1: AHU-1 supplies ventilation, heat and natural cooling to the building. AHU-1 is a constant airflow system consisting of a mixing box, filter section, supply fan, and electric heating coil. A relief air louver in the dining room opens to relieve building pressure. Alaska Energy Engineering LLC CBS Energy Audit 115 Senior Center Air Handling Unit AHU-2: AHU-2 supplies makeup air and natural cooling to the kitchen hood. AHU-2 is a constant airflow system consisting of a mixing box, filter section, and supply fan. Exhaust Fan EF-1: EF-1 is a cabinet fan that draws exhaust air from the toilets and janitor’s closet. Exhaust Fan EF-2: EF-2 is a roof-mounted exhaust fan serving the kitchen hood. Exhaust Fan EF-3: EF-3 is a wall-mounted exhaust fan serving the pantry. Analysis AHU-1: • The 45 kW heating coil in the air handling unit has several stages of heat. • The fan cabinet and ducts in the attic are under insulated. • The outside air louver was replaced with a smaller louver, limiting the natural cooling potential of the system. • Ceiling fans in the dining room would move heated air downward. AHU-2: The fan cabinet and ducts in the attic are under insulated. EF-1: The fan cabinet and ducts in the attic are under insulated. EF-2: The duct in the attic is under insulated. Exhaust Fan EF-3: A natural cooling system can be used to recover the refrigeration heat and transfer it to the dining room. Domestic Hot Water System Description An electric HW heater supplies domestic hot water to the building. The heater has a 15 kW heater element. The lavatory faucet aerators have a flow rate of 2.5 gpm. The faucets are not auto-sensing. Analysis A hot water heater with multiple stages will incur smaller demand charges because less than full capacity is likely to keep up with water demand most of the time. The domestic hot water piping is not insulated. Ultra-low aerators of 0.5 gpm are available for lavatory faucets. Auto-sensing faucets reduce the water flow time three seconds during each use. Automatic Control System Description The building has an electric control system. The system is standalone and does not interface with the City’s community-wide Honeywell system. Basic Control Sequences Baseboard Heaters: Room thermostat operates the heater to maintain setpoint. Thermostat is programmable for occupied/unoccupied setpoints. Alaska Energy Engineering LLC CBS Energy Audit 116 Senior Center Air Handling Unit AHU-1: • AHU-1 operates in accordance with an occupied/unoccupied time clock. • Mixing dampers modulate to supply a minimum of 10% outside air. When EF-2 operates, the dampers modulate to 100% outside air. • The heating coil stages are operated to maintain the supply temperature setpoint. Air Handling Unit AHU-2: • AHU-2 operates to maintain the room temperature setpoint. • Mixing dampers modulate to maintain the supply air setpoint. Exhaust Fan EF-1: Operates when any light switch is turned on in the men’s toilet, women’s toilet, or the janitor closet. Exhaust Fan EF-2: Manually operated by wall switch. Exhaust Fan EF-3: Switch with room thermostat opens a relief air louver and operates the fan to maintain the room temperature setpoint. Electric HW heater: Immersion thermostat operates the heating elements to maintain setpoint. Analysis The control system was installed in 1988 when the building is constructed and is at the end of its service life. Baseboard Heaters: The room thermostats are difficult to program for occupied/unoccupied setback. Air Handling Unit AHU-1: The controls for AHU-1 are not maintaining the control sequences. • The control sequence for the mixing dampers is over-ventilating the building, incurring an energy penalty. The dampers allow too much outside air. • The heating stages are not properly controlled. The electric demand indicates that all stages operate when heat is needed. Air Handling Unit AHU-2: • The room thermostat is not controlling the fan. • The mixing dampers are not modulating properly. Exhaust Fan EF-1: Adding a timing control will allow the fan to operate for a period after the light switch is turned off. Exhaust Fan EF-3: • The thermostat is not controlling the fan. • The makeup air louver by the back door is stuck in the closed position. Electric HW heater: A demand control that stages the heating elements will reduce electric demand. Lighting Description The interior lighting is T12 fluorescent controlled by wall switches. Alaska Energy Engineering LLC CBS Energy Audit 117 Senior Center Analysis The lighting can be upgraded to more efficient lighting using T8 or T5 lamps. Occupancy sensors can be used to turn off lighting in the offices and toilet rooms. The lighting level in the dining room is higher than needed. Electric Equipment Description The building has two office computers that are left on continuously. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. Behavioral or Operational Senior Center-1: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Lighting was left on in unoccupied rooms. Scope: Turning off lighting is an ECO with immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. This ECO requires behavior changes where occupants regularly turn off lighting rather than leave it on. Analysis: This ECO is recommended without analysis. Senior Center-2: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment is an ECO with immediate payback. This ECO requires behavior changes where occupants regularly turn off equipment when they are finished with it. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 118 Senior Center Senior Center-3: Reduce Entrance Temperature Purpose: Heat will be saved by reducing the temperature setpoints of entrance heater. The heater is located near building entrances to minimize the thermal comfort impacts of cold air entering the building and to dry the floor. The higher the temperature at the entrance the greater the amount of heat loss to outdoors, whether the doors are open or closed. Reducing the temperature setpoint to the minimum needed for thermal comfort and moisture control will reduce heat loss. Scope: Turn entrance setpoints down to 55°F and determine if this is adequate for thermal comfort and moisture control. Adjust as needed. Mark the desired setpoint on the thermostat so it can be visually verified. Analysis: This ECO is recommended without analysis. Senior Center-4: Reduce Refrigeration Purpose: Electricity will be saved if the amount of refrigeration equipment is reduced. Scope: The Senior Center has several freezers for storing food. The freezers and refrigerators are all owned by Southeast Senior Services. As the equipment ages and fails, freezer space can be reduced by scheduling food deliveries closer to when it is needed or renting storage off-site. Analysis: This ECO is recommended without analysis. Senior Center-5: Insulate HW Piping Purpose: Heat will be saved if the hot water piping is insulated. Scope: Insulate the hot water piping in the mechanical room. Analysis: This ECO is recommended without analysis. Senior Center-6: Weather-Strip Doors Purpose: Heat will be saved if doors are properly weather-stripped to reduce infiltration. The corridor doors do not have adequate weather-stripping. Scope: Install or repair the weather-stripping on all doors. Analysis: This ECO is recommended without analysis. Senior Center-7: Replace Thermostats Purpose: Heat will be saved if the baseboard thermostats are replaced with a model that is simple to program the occupied and unoccupied setpoints. Scope: Replace the baseboard thermostats and program them with occupied/unoccupied setpoints. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 119 Senior Center Senior Center-8: Increase Ductwork Insulation Purpose: Heat will be saved by adding insulation to the ductwork in the attic and crawlspace. Scope: Add insulation to the ductwork in the attic and crawlspace. Analysis: The duct insulation in the attic and crawlspace is in poor condition and/or under insulated for a cold space. Adding insulation will significantly reduce heat loss and is certain to provide a life cycle savings. This ECO is recommended without analysis. High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. Senior Center-9: Reduce Dining Room Lighting Purpose: Electricity will be saved by reducing the lighting in the dining room. Scope: Reduce the dining room lighting level by turning off one of the three switches that control the lighting or by delamping the fixtures that illuminate the circulation space around each table. Analysis: The dining room lighting level is 65-105 FC, which exceeds the recommended level of 35-50 FC. The analysis assumes that 33% of the lamps can be turned off while maintaining acceptable lighting levels. This ECO will reduce annual electricity use by 3,500 kWh and energy costs by $370. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $300 ($700) ($6,700) ($7,100) Note: Negative numbers, in parenthesis, represent savings. Senior Center-10: Install Water-Conserving Aerators Purpose: Electricity will be saved by using water-conserving aerators on sinks and lavatories. Scope: Replace lavatory aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 60 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual electric use by 2,100 kWh and energy costs by $180. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $200 $0 ($3,300) ($3,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 120 Senior Center Senior Center-11: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Analysis: The building has 2 computers. The analysis assumes that the computers are not in use for 15 hours of the day. The power settings were not checked on each machine, so the following analysis assumes that 50% of the computers are not set to enter sleep mode when inactive. Setting the power settings from screen saver to sleep mode will reduce annual electricity use by 830 kWh and energy costs by $70. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 270 kWh and energy costs by $20. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $100 $0 ($1,300) ($1,200) Turn Off $100 $0 ($400) ($300) Total $200 $0 ($1,700) ($1,500) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 121 Senior Center Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. Senior Center-12: Install Refrigeration Heat Recovery Purpose: Heat will be saved if the waste heat from the pantry refrigeration units is transferred to the Dining Room instead of the current practice of discharging it outdoors. Scope: Install a ventilating fan and thermostat control to transfer air heated by the refrigeration units to the Dining Room. Analysis: This ECO will reduce annual electric use by 15,000 kWh and energy costs by $1,300. In addition, removing the heat from the condenser room will improve refrigeration efficiency. This efficiency gain is not included in the energy savings because it is difficult to quantify. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $9,500 $2,600 ($23,500) ($11,400) Note: Negative numbers, in parenthesis, represent savings. Senior Center-13: Install Domestic HW Heater Demand Controls Purpose: Demand charges will be reduced by installing a demand controller on the domestic hot water heater. Scope: Install two additional immersion thermostats. Rewire the heater so each thermostat controls a 5 kW element. Configure setpoints to limit demand. Analysis: The analysis assumes that 10 kW of recovery is sufficient 9 months, and 15 kW is needed for 3 months each year. The tank should be monitored to verify this assumption. This ECO will reduce annual electric demand by 45 kW and energy costs by $180. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $1,500 $0 ($3,200) ($1,700) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 122 Senior Center Senior Center-14: Replace Entrance Doors Purpose: Heat will be saved if the entrance doors with single pane glazing and no thermal breaks are replaced with energy efficient doors. Scope: Replace the entrance doors with thermal broken doors with insulating glazing. Analysis: This ECO will reduce annual electricity use by 2,200 kWh and energy costs by $190. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $3,000 $0 ($3,500) ($500) Note: Negative numbers, in parenthesis, represent savings. Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. Senior Center-15: Increase Roof Insulation Purpose: Electricity will be saved by adding insulation to the roof. Scope: Add additional blown-in fiberglass insulation to increase the roof R-value from R-39 to R-58. Analysis: This ECO will reduce annual electricity use by 3,600 kWh and energy costs by $300. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,800 $0 ($5,600) $1,200 Note: Negative numbers, in parenthesis, represent savings. Senior Center-16: Replace HVAC Motors Purpose: Electricity will be saved if motors are upgraded to NEMA Premium® motors. Scope: Replace the motor in AHU-1with a NEMA Premium® motor. Analysis: This ECO will reduce annual electricity use by 240 kWh, electric demand by 1 kW, and energy costs by $25. AHU-1 only operates 27% of the year, which is too few hours to produce energy savings to offset the replacement cost. This ECO is not recommended. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $600 $0 ($500) $100 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 123 Senior Center Senior Center-17: Upgrade Lighting Purpose: Electricity will be saved if the T12 lighting is upgraded to energy efficient lighting. Scope: Retrofit the lighting fixtures with T8 lamps and electronic ballasts. Analysis: Upgrading the lighting will reduce annual electricity use by 3,200 kWh, electric demand by 16 kW and energy costs by $330. However, the relatively few operating hours limit the energy savings that is needed to offset the investment. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,500 $0 ($6,000) $500 Note: Negative numbers, in parenthesis, represent savings. Senior Center-18: Replace Control System Purpose: The electric/electronic control system is a dated technology that is difficult to support/repair. The controls do not operate properly, resulting in higher energy use. Converting the controls to a DDC system will ease maintenance and interoperability. Electricity will be saved if the building energy systems are optimized through a retro- commissioning process. The energy audit revealed that the building is over- ventilated, demand control ventilation is not being used, supply air reset controls are not in use, the control system is out of calibration, the system are out of adjustment, and there is opportunity to optimize the control strategies. Scope: Replace the control system and retro-commission the building: − Rebalancing the HVAC systems − Reduce minimum outside air flow − Utilize demand and schedule controlled ventilation − Utilize supply air reset control − Utilize occupancy sensor control − Electric heat demand limiting − Temperature setback Analysis: The energy audit has revealed that retro-commissioning of the control system is needed. This presents an opportunity to convert the control system to the citywide Honeywell system. This ECO is estimated to reduce annual electricity use by 25,000 kWh, electric demand by 120 kW, and energy costs by $2,600. The energy savings do not offset the cost of replacing the controls. However, energy savings offers incentive to replace the controls in the near future rather than delay until the system becomes a greater maintenance liability. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $67,200 $0 ($47,400) $19,800 Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 124 Senior Center Senior Center-19: Install Ceiling Fans Purpose: Heat will be saved by installing ceiling fans in the dining room to move warm air down to floor level. Scope: Install two ceiling fans with variable speed controls. Analysis: The analysis assumes that the ceiling fans will keep the ceiling level 10°F cooler, reducing heat loss through the roof. This ECO will reduce annual electricity use by 490 kWh and energy costs by $45. The energy savings is unable to offset the cost of the ceiling fans. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $2,300 $0 ($800) $1,500 Note: Negative numbers, in parenthesis, represent savings. Senior Center-20: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: Building operating personnel users should be aware of how demand charges are incurred. Billing demand is the maximum average load over any fifteen consecutive minutes during the billing period. The most effective demand control strategies are: − Minimize the size of electric equipment. − Schedule operations so large electric loads operate for long periods. − Reduce the equipment size and operate it for longer periods. − Sequence the operation of large loads rather than operate them concurrently. Senior Center-21: Close Inner Entrance Doors Purpose: Heat will be saved if the inner door of the line crew entrance is closed so that the entrance functions as an arctic entrance. Scope: Close the inner entrance door during the primary heating season of September 1 to May 1. An ADA door operator is needed. Analysis: The life cycle energy savings will not offset the high cost of installing ADA operators on the entrance doors. This is ECO is not recommended. Senior Center-22: Replace Windows Purpose: Heat will be saved by replacing the windows. Scope: Replace the double pane windows with energy efficient triple pane windows. Analysis: Previous analysis has shown that replacing older double pane windows with modern, energy efficient triple pane units will not provide a life cycle savings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 125 Senior Center Senior Center-23: Increase Wall Insulation Purpose: Heat will be saved by adding insulation to the exterior walls. Analysis: The walls were insulated to the standards that existed when they were constructed. The assembly is below current optimal levels of R-25+. Previous analyses have shown that that adding insulation to the wall will not provide a life cycle savings because of the high cost of replacing the interior or exterior finishes. If the siding is replaced in the future, additional wall insulation is warranted. Senior Center-24: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings. This ECO is not recommended. Senior Center-25: Install Variable Speed Kitchen Hood Purpose: Heat and electricity will be saved if the kitchen hood is replaced with a variable speed hood. Analysis: Variable speed kitchen hoods are listed for reduced airflow during non-peak cooking periods. Replacing the existing hood with a variable flow hood will not provide a life cycle savings because the high cost of replacing the hood and exhaust fan combined with the relatively few number of operating hours will not be offset by future energy savings. This ECO is not recommended. Senior Center-26: Lighting Occupancy Sensor Control Purpose: Electricity use will be reduced by installing occupancy sensor in the toilet rooms that will automatically turn the lighting off when rooms are unoccupied. Scope: Install occupancy sensors in the toilets for lighting control. Analysis: Occupancy sensors provide a life cycle savings in most high performance buildings. However, the Senior Center has relatively few operating hours, which reduces the energy saving potential of the sensors. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 126 Senior Center SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Electricity Current Energy Costs $14,000 Behavioral and Operational Senior Center-1: Turn Off Lighting Senior Center-2: Turn Off Equipment Senior Center-3: Reduce Entrance Temperature Senior Center-4: Insulate HW Piping Senior Center-5: Weather-strip Doors Senior Center-6: Reduce Refrigeration Senior Center-7: Replace Thermostats Senior Center-8: Increase Duct Insulation Energy Savings (Estimated) ($810) Top Priority Senior Center-9: Reduce Dining Room Lighting ($370) Senior Center-10: Install Water Conserving Aerators ($180) Senior Center-11a: Set Computers to Sleep Mode ($70) Senior Center-11b: Turn Off Inactive Computers ($20) Medium Priority Senior Center-12: Install Refrigeration Heat Recovery ($1,280) Senior Center-13: Install HW Heater Demand Controls ($180) Senior Center-14: Replace Entrance Doors ($190) ECO Savings ($3,100) (22%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 127 Senior Center Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational Senior Center-1: Turn Off Lighting $0 Senior Center-2: Turn Off Equipment $0 Senior Center-3: Reduce Entrance Temperature $100 Senior Center-4: Insulate HW Piping $200 Senior Center-5: Weather-strip Doors $500 Senior Center-6: Reduce Refrigeration $500 Senior Center-7: Replace Thermostats $1,800 Senior Center-8: Increase Duct Insulation $5,000 Totals $8,100 $0 ($14,800) ($6,700) Top Priority Senior Center-9: Reduce Dining Room Lighting $300 ($700) ($6,700) ($7,100) Senior Center-10: Install Water Conserving Aerators $200 $0 ($3,300) ($3,100) Senior Center-11a: Set Computers to Sleep Mode $100 $0 ($1,300) ($1,200) Senior Center-11b: Turn Off Inactive Computers $100 $0 ($400) ($300) Medium Priority Senior Center-12: Install Refrigeration Heat Recovery $9,500 $2,600 ($23,500) ($11,400) Senior Center-13: Install HW Heater Demand Controls $1,500 $0 ($3,200) ($1,700) Senior Center-14: Replace Entrance Doors $3,000 $0 ($3,500) ($500) Totals $22,700 $1,900 ($56,700) ($32,100) ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic electricity use • Energy and life cycle cost analysis calculations Alaska Energy Engineering LLC CBS Energy Audit 128 Senior Center This page intentionally left blank Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 15,800 104 14,560 68 14,400 67 14,600 68 59,360 Feb 16,080 104 14,520 63 12,640 64 15,160 66 58,400 Mar 14,160 104 12,720 69 11,960 65 13,040 69 51,880 Apr 17,280 110 14,040 68 13,800 65 14,400 66 59,520 May 9,560 104 11,880 65 9,600 62 12,000 68 43,040 Jun 7,840 61 8,760 55 9,560 58 9,840 59 36,000 Jul 7,120 63 8,320 56 8,320 57 7,840 60 31,600 Aug 6,640 57 7,120 52 7,680 51 9,880 57 31,320 Sep 8,440 60 7,280 58 7,080 55 10,240 48 33,040 Oct 7,720 56 9,560 56 8,480 62 10,680 56 36,440 Nov 11,080 65 10,160 62 11,800 65 14,200 57 47,240 D 13 160 66 12 120 66 11 920 69 13 080 60 50 280 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 13,160 66 12,120 66 11,920 69 13,080 60 50,280 Total 134,880 131,040 127,240 144,960 134,530 Average 11,240 79 10,920 62 10,603 62 12,080 61 11,211 Load Factor 19.4% 24.3% 23.5% 27.1% 66 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 1,303 165 1,467 1,320 169 1,489 1.5% Feb 1,153 154 1,307 1,367 161 1,529 17.0% Mar 1,095 157 1,252 1,187 171 1,358 8.5% Apr 1,252 157 1,408 1,303 158 1,461 3.7% May 893 144 1,037 1,099 169 1,268 22.3% Jun 889 129 1,018 914 132 1,046 2.8% Jul 777 126 903 734 137 870 -3.6% Aug 719 102 821 918 124 1,042 26.8% Sep 665 118 783 949 91 1,040 32.9% Oct 791 144 936 987 121 1,107 18.3% Nov 1,082 157 1,238 1,286 124 1,410 13.8% Dec 1,092 171 1,263 1,191 135 1,325 5.0% Total $ 11,711 $ 1,722 $ 13,433 $ 13,253 $ 1,693 $ 14,946 11.3% Average $ 976 $ 144 $ 1,119 $ 1,104 $ 141 $ 1,245 11.3% Cost ($/kWh) 0.1056 89% 11% 0.1031 -2.3% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center August 8, 2009 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 20 40 60 80 100 120 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center August 8, 2009 $ 0 $ 200 $ 400 $ 600 $ 800 $ 1,000 $ 1,200 $ 1,400 $ 1,600 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 200 $ 400 $ 600 $ 800 $ 1,000 $ 1,200 $ 1,400 $ 1,600 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 0 10 20 30 40 50 60 70 80 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Qty Unit Base Cost Year 0 Cost Construction Costs Senior Center-1: Turn Off Lighting 1 job $0 $0 Senior Center-2: Turn Off Equipment 1 job $0 $0 Senior Center-3: Reduce Entrance Temperature 1 job $100 $100 Senior Center-4: Insulate HW Piping 1 job $200 $200 Senior Center-5: Weather-strip Doors 1 job $500 $500 Senior Center-6: Reduce Refrigeration 1 job $500 $500 Senior Center-7: Replace Thermostats 12 ea $150 $1,800 Senior Center-8: Increase Duct Insulation 1 job $5,000 $5,000 Energy Costs Electric Energy 1 - 25 -9,500 kWh $0.085 ($14,770) Net Present Worth ($6,670) Senior Center-9: Reduce Dining Room Lighting Energy Analysis # Fixtures watts/ea Savings kW kWh 48.0 92 -33% -1.5 -3,532 Lamp Cost August 8, 2009 Year 0 0 0 0 0 0 0 0 Hours 2,424 Lamp Cost Option lamps $/lamp Life, hrs $,yr Existing -96 4.00 10,000 -93 Scheduled 64 4.00 10,000 62 Savings -31 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Labor 1 ea $300 $300 Annual Costs Added lamp life 1 - 25 1 ea ($31.03) ($670) Energy Costs Electric Energy 1 - 25 -3,532 kWh $0.085 ($5,492) Electric Demand 1 - 25 -17 kW $3.90 ($1,247) Net Present Worth ($7,110) Senior Center-10: Install Water Conserving Aerators Energy Analysis HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kWh Electric 2.5 0.5 15 -10,950 -2,141 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 6 ea $33 $200 Energy Costs Electric Energy 1 - 25 -2,141 kWh $0.085 ($3,328) Net Present Worth ($3,128) 0 Year Use/Day 60 0 Hours 2,424 2,424 Year Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center August 8, 2009 Senior Center-11a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 2 -125 16 24 -1,664 50% -832 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Modify power settings 1 ea $100 $100 Energy Costs Electric Energy 1 - 25 -832 kWh $0.085 ($1,294) Net Present Worth ($1,194) Senior Center-11b: Turn Off Inactive Computers Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 2 -20 16 24 -266 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Modify power settings 1 ea $100 $100 Energy Costs Electric Energy 1 - 25 -266 kWh $0.085 ($414) Net Present Worth ($314) Senior Center-12: Install Refrigeration Heat Recovery 0 Year kW 0 Year kW -0.3 0.0 Energy Analysis kW EER Heat, MBH Hours kBTU kWh 2.0 10 20 8,030 52,998 15,528 Fan CFM ΔP η, fan BHP kW Hours kWh 900 0.5 45% 0.16 0.16 2,650 415 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Ventilating fan and ductwork 1 ea $7,500 $7,500 Controls 1 ea $2,000 $2,000 Annual Costs Fan maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 -15,114 kWh $0.085 ($23,498) Net Present Worth ($11,405) 0 Year 0 Load Factor 33% η, motor 75% Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center August 8, 2009 Senior Center-13: Install HW Heater Demand Controls Energy Analysis Option kW Months Total kW Exist -15 12 -180 New 10 9 90 New 15 3 45 -45 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Add thermostats and rewire 1 ea $1,500 $1,500 Energy Costs Electric Demand 1 - 25 -45 kW $3.90 ($3,210) Net Present Worth ($1,710) Senior Center-14: Replace Entrance Doors Energy Analysis Room R,old R,new Area, sqft kBTU kWh Entrance 0.5 3.0 21 -7,665 -2,246 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace entrance doors 21 sqft $143 $3,003 Energy Costs Electric Energy 1 - 25 -2,246 kWh $0.085 ($3,492) Net Present Worth ($489) Factor 100% Year 0 Year 0 Net Present Worth ($489) Senior Center-15: Increase Roof Insulation Energy Analysis Option R-value Tin Tout Loss, kBTU kWh Exist -38 65 41 -35,409 -10,375 Added 58 65 41 23,199 6,797 Savings -3,577 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Mob/Demob cost 1 ea $2,000.00 $2,000 Blow-in R-10 attic insulation 6,400 sqft $0.75 $4,800 Energy Costs Electric Energy 1 - 25 -3,577 kWh $0.085 ($5,562) Net Present Worth $1,238 6,400 6,400 Year 0 0 Area Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center August 8, 2009 Senior Center-16: Replace HVAC Motors Energy Analysis Unit HP η, old η, new Hours ΔkWh AHU-1 1 76.7% 85.5% 2,424 -243 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace 1 HP motor 1 ea $600 $600 Energy Costs Electric Demand 1 - 25 -1 kW $3.90 ($86) Electric Energy 1 - 25 -243 kWh $0.085 ($377) Net Present Worth $137 Senior Center-17: Upgrade Lighting Energy Analysis Room # Fixtures watts/ea kW kWh Common -59 92 -5.4 -13,157 Office/Conf -6 92 -0.6 -1,338 Common 59 72 4.2 10,297 Office/Conf 6 72 0.4 1,047 Savings -16 -3,151 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Reballast and relamp fixtures 65 fixtures $125 $8,125 EC Year Year 2,424 2,424 2,424 Hours 0 2,424 0 ΔkW -0.10 Energy Costs Electric Energy 1 - 25 -3,151 kWh $0.085 ($4,899) Electric Demand 1 - 25 -16 kW $3.90 ($1,113) Net Present Worth $2,113 Senior Center-18: Replace Control System Points List Qty Unit Pts/ea AHU-1 1 ea 8 AHU-2 1 ea 3 Pantry HRU 1 ea 3 EF-1 1 ea 1 EF-2 1 ea 1 Baseboard heaters 12 ea 1 Thermostats 12 ea 1 Domestic hot water 2 ea 1 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace automatic controls 42 pts $1,600 $67,200 Energy Costs Electric Energy 1 - 25 -25,000 kWh $0.085 ($38,868) Electric Demand 1 - 25 -120 kW $3.90 ($8,560) Net Present Worth $19,772 12 12 2 0 1 1 3 3 42 Year Points 8 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Senior Center August 8, 2009 Senior Center-19: Install Ceiling Fans Energy Analysis Option Area Roof R-value Tosa kBTU kWh Exist -1,260 38 41 -11,328 -3,319 Fans 1,260 38 41 8,423 2,468 -851 Number watts kW Hours 2 75 0.2 2,424 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install ceiling fans 2 ea $750 $1,500 Electrical 2 ea $400 $800 Energy Costs Electric Energy 1 - 25 -487 kWh $0.090 ($805) Net Present Worth $1,495 Trm 80 70 kWh 364 Year 0 0 This page intentionally left blank Alaska Energy Engineering LLC CBS Energy Audit 129 Wastewater Treatment Plant Section 9 Wastewater Treatment Plant INTRODUCTION The Wastewater Treatment Plant contains process, operational, and office spaces. The building operates continually. ENERGY CONSUMPTION AND COST The building energy sources are electricity and fuel oil. Fuel oil is consumed by the boiler for heat and domestic hot water and electricity supplies all other loads, including process loads. The following table summarizes the energy consumption and cost. Energy Consumption and Cost Source Consumption Cost Energy, MMBH Fuel Oil 10,600 gals $25,400 1,400 (48%) Electricity 460,000 kWh $45,000 1,500 (52%) Totals - $70,400 2,900 (100%) 1. Consumption is the average from 2005-2008. Costs are based on 2009 prices. Trends Fuel Oil: Fuel oil use varied from year-to-year over the previous four years. Electricity: Electricity use and demand has increased annually over the past four years. Use also varies month-to-month due to changes in rainfall. Electric demand is steady from month-to-month at 90 kW. Effective cost—energy plus demand charges—is 9.4¢ per kWh. Under the tiered rate structure, each additional kWh consumed costs 8.5¢ per kWh. Energy consumption data is located at the end of this section. DESCRIPTION OF SYSTEMS Envelope The building envelope was not audited because the building is not heated year-round, which limits the energy conservation opportunities. The door weather-stripping is in poor condition. Alaska Energy Engineering LLC CBS Energy Audit 130 Wastewater Treatment Plant Heating System Description The heating system consists of two oil-fired hot water boilers and a hydronic distribution system with constant speed pumps CP-1A and CP-1B supplying heating water to the building. The heating units consist of ventilation heating coils and unit heaters. Analysis The boilers are turned off from April through October. The boilers do not have flue dampers to minimize the flow of heated air through the boiler and up the chimney when it is not operating. Converting to a primary/secondary pumping system with variable speed pumping will decrease pumping costs by allowing pump energy consumption to vary with the heating load. The unit heaters and cabinet unit heaters do not have automatic valves to shut off the heating water flow when heat is not required. Heating units are not interlocked to turn off when overhead doors are open. Ventilation System Description Supply Fan SF-1and Return Fan RF-1: SF-1 is an air handling unit that supplies constant flow mixed air to the plant. The unit has a mixing box, filter section, heating coil, and supply fan. Return air is drawn by RF-1 where it is returned to SF-1or scrubbed prior to being exhausted. Supply Fan SF-2: SF-2 is an air handling unit that supplies variable flow mixed air to the offices. The unit has a mixing box, filter section, and supply fan. Return air flows through a ceiling plenum back to the unit. Each room has a variable air volume terminal box that modulates airflow. Supply Fan SF-3: SF-3 is an air handling unit that supplies constant flow plenum air to the perimeter area of the offices. The unit has a filter section, heating coil, and supply fan. Each zone has a reheat coil. Supply Fan SF-4: SF-4 is an air handling unit that supplies constant flow mixed air to the clarifier room. The unit has a filter section, heating coil, and supply fan. Supply Fan SF-5: SF-5 is an air handling unit that supplies constant flow mixed air to the boiler room. The unit has a mixing box, filter section and supply fan. Analysis Supply Fan SF-1and Return Fan RF-1: SF-1 is supplying 25% outside air, which exceeds the minimum outside air requirement. Supply Fan SF-4: • SF-4 is supplying 50% outside air, which exceeds the minimum outside air requirement. • There is no relief air louver in the clarifier room. There is no boiler room heat recovery. The ductwork is not sealed. Alaska Energy Engineering LLC CBS Energy Audit 131 Wastewater Treatment Plant Domestic Hot Water System Description Two oil-fired hot water heaters supply domestic hot water to the building. Hot water recirculating pump CP-2 maintains hot water in the distribution piping. The lavatory faucet aerators have a flow rate of 2.5 gpm. The faucets are not auto-sensing. Analysis Pump CP-2 has been replaced with a much larger pump. The hot water piping near the heaters is not insulated. Ultra-low aerators of 0.5 gpm are available for lavatory faucets. Automatic Control System Description The building HVAC systems are controlled by local controllers and a pneumatic/electric control system. The system is monitored by the City’s community-wide Honeywell system. Basic Control Sequences Boilers B-1 and B-2: The boilers are controlled by a Tekmar controller in a lead/standby configuration. The controller is operating the boilers at 120°F on and 140°F off. Each boiler also has an operating thermostat that can be used to bypass the controller. The setpoints were 160°F on and 190°F off. Pumps CP-1A and CP-1B: Operate in a lead/standby configuration with manual switchover. Supply Fan SF-1 and Return Fan RF-1: • Operates continuously • Mixing dampers modulate to maintain the discharge temperature setpoint • Heating coil automatic valve modulates to maintain the room temperature setpoint Supply Fan SF-2: • Operates continuously • Mixing dampers modulate to maintain the discharge temperature setpoint • Terminal variable volume boxes modulate airflow to maintain the room temperature setpoint Supply Fan SF-3: • Operates continuously • Heating coil automatic valve modulates to maintain the discharge temperature setpoint Supply Fan SF-4: • Operates continuously • Mixing dampers modulate to maintain the discharge temperature setpoint • Heating coil automatic valve modulates to maintain the room temperature setpoint Alaska Energy Engineering LLC CBS Energy Audit 132 Wastewater Treatment Plant Supply Fan SF-5: Fan operates and mixing dampers modulate to maintain the discharge temperature setpoint Hot Water Heaters: Immersion thermostat in each heater operates to maintain the heater setpoint. Hot Water Recirculating Pump CP-2: Operates continuously. Analysis Boilers B-1 and B-2: The controller is maintaining the boilers at 120-140°F. This temperature is too low to preclude formation of corrosive acids in the chimneys. Supply Fan SF-1and Return Fan RF-1: The mixed air dampers are allowing 15% outside air, which exceeds minimum requirements. Supply Fan SF-2: The VFD is maintaining the fan at full speed. Supply Fan SF-3: The supply air setpoint is too high. Supply Fan SF-4: • The supply air setpoint is too high • The amount of outside air is too high • Humidistat control of the mixing dampers will optimize the amount of ventilation air Supply Fan SF-5: The setpoint should be increased to maintain the boiler room at as high a temperature as practical. Hot Water Heaters: The heater setpoints of 150°F are too high Electric Equipment Description The building has five computers that are left on continuously. The process equipment is driven by numerous motors. There is a 75 kVA and a 15 kVA transformer in the main bay. Analysis Computers consume energy even when they are not in use, even if they enter sleep mode. Turning them off overnight reduces their energy consumption and conserves hydroelectric power resources. The motors are not NEMA Premium® efficient. The transformers are less efficient than modern transformers. Alaska Energy Engineering LLC CBS Energy Audit 133 Wastewater Treatment Plant ENERGY CONSERVATION OPPORTUNITIES Behavioral or Operational The following ECOs are recommended for implementation. They require behavioral or operational changes that can occur with minimal investment to achieve immediate savings. These ECOs are not easily quantified by economic analysis because behavioral or operation changes cannot be accurately predicted. They are recommended because there is a high likelihood they will offer a life cycle savings, represent good practice, and are accepted features of high performance buildings. WWTP-1: Turn Off Lighting Purpose: Electricity will be saved if lighting is turned off when rooms are unoccupied. Lighting was left on in unoccupied rooms. Scope: Turning off lighting is an ECO with immediate payback. Unless room occupancy changes often, the lighting can be turned off and on with minimal effect on lamp life. This ECO requires behavior changes where occupants regularly turn off lighting rather than leave it on. Analysis: This ECO is recommended without analysis. WWTP-2: Turn Off Equipment Purpose: Electricity will be saved if equipment is turned off when it is not in use. Occupants will often habitually leave equipment on because of long-standing practices. Scope: Turning off unused equipment is an ECO with immediate payback. This ECO requires behavior changes where occupants regularly turn off equipment when they are finished with it. Analysis: This ECO is recommended without analysis. WWTP-3: Reduce HW Temperature Purpose: Heat will be saved if the setpoints on the hot water heaters are lowered. Scope: Lower the hot water heater setpoint to 120°F. Analysis: The setpoints are at 150°F which is hotter than needed for general cleaning and showers. This ECO is recommended without analysis. WWTP-4: Insulate HW Piping Purpose: Heat will be saved if the hot water piping is insulated. Scope: Insulate the hot water piping in the boiler room. Analysis: This ECO is recommended without analysis. WWTP-5: Weather-Strip Exterior Doors Purpose: Heat will be saved if exterior doors are properly weather-stripped to reduce infiltration. Scope: Install or repair the weather-stripping on all exterior doors. Analysis: This ECO is recommended without analysis. Alaska Energy Engineering LLC CBS Energy Audit 134 Wastewater Treatment Plant WWTP-6: Interlock Heaters with Overhead Doors Purpose: Heat will be saved if the heating units turn off automatically when the overhead doors are open. Scope: Install limit switches on each automatic door to turn off the heating units when the door is open. Analysis: This ECO is recommended without analysis. High Priority The following ECOs are recommended for implementation because they are low cost measures that offer a high return on investment. WWTP-7: Install Water-Conserving Aerators Purpose: Fuel oil will be saved by using water-conserving aerators on sinks and lavatories. Scope: Replace lavatory aerators will ultra-low flow 0.5 gpm aerators. Analysis: The analysis assumes that the lavatory faucets are used an average of 30 times per day. Replacing the 2.5 gpm aerators with 0.5 gpm aerators will reduce annual fuel oil use by 30 gallons and energy costs by $70. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $100 $0 ($2,100) ($2,000) Note: Negative numbers, in parenthesis, represent savings. WWTP-8: Modify Computer Power Settings Purpose: Electricity will be saved if the computer and monitor power settings are set to sleep mode and they are turned off during non-work hours. The computer equipment is left on overnight and on weekends. The amount of energy used when the computer is not in use varies with the power settings of the machine. If the computer stays active and the monitor switches to screen saver, the power use does not drop. If the computer and monitor enter sleep mode or are turned off, the power use drops significantly. Limited hydroelectric power and increasing electricity costs necessitate a review of the policy to keep computers on continuously. At a minimum, computers and monitors should enter sleep mode after 30 minutes of inactivity. This will reduce energy use from an average of 150 watts to 25 watts. Turning both off will reduce energy use an additional to 15-25 watts. Alaska Energy Engineering LLC CBS Energy Audit 135 Wastewater Treatment Plant Scope: Set all computers and monitors to enter sleep mode during inactive times. Confer with the Information Systems Manager on a revised operational model that allows users to turn off computers when they are not in use. There are software programs that can remotely turn on network computers for software updates and backups and turn them back off. Most people routinely turn off computers at home and will adapt the same behavior at work if the policy changes. Analysis: The building has five computers. The analysis assumes that the computers are not in use for 15 hours of the day. The power settings were not checked on each machine, so the following analysis assumes that 40% of the computers are not set to enter sleep mode when inactive. Setting the power settings from screen saver to sleep mode will reduce annual electricity use by 1,500 kWh and energy costs by $130. Turning the computers and monitors off rather than in sleep mode will reduce annual electricity use an additional 600 kWh and energy costs by $50. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Option Construction Maintenance Energy Life Cycle Cost Sleep Mode $100 $0 ($2,300) ($2,200) Turn Off $100 $0 ($900) ($800) Total $200 $0 ($3,200) ($3,000) Note: Negative numbers, in parenthesis, represent savings. WWTP-9: Replace Hot Water Recirculating Pump Purpose: Electricity will be saved if the hot water recirculating pump is replaced with a properly sized pump. Scope: Replace the hot water recirculating pump. The current pump is an oversized replacement for the original pump. Analysis: This ECO will reduce annual electricity use by 3,200 kWh, electric demand by 4 kW, and energy costs by $290. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $600 $0 ($5,300) ($4,700) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 136 Wastewater Treatment Plant Medium Priority Medium priority ECOs require planning and investment, but warrant investment as funding allows because they offer a life cycle savings. The ECOs are listed from highest to lowest priority. WWTP-10: Install Unit Heater Automatic Valves Purpose: Fuel oil will be saved if each unit heater has an automatic valve that shuts off the hydronic heating flow when heat is not needed. The heater coil is continuously hot which results in convective heat loss when the heater fan is not operating. While some of the heat loss may be useful, it is often not. Scope: Install an automatic valve on each unit heater to shut off the hydronic heating flow when heat is not needed. Analysis: This ECO will reduce annual fuel oil use by 190 gallons and energy costs by $450. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $4,000 $0 ($14,200) ($10,200) Note: Negative numbers, in parenthesis, represent savings. WWTP-11: Boiler Flue Damper Purpose: Heat will be saved by installing a flue damper in each boiler chimney to minimize the flow of heated air through the boilers and up the chimneys. Scope: Install a damper in each boiler flue and control it to open prior to firing the boiler. Analysis: This ECO will improve the boiler seasonal efficiency by a minimum of 1.5% and reduce annual fuel oil use by 160 gallons and energy costs by $390. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $6,000 $1,300 ($12,400) ($5,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 137 Wastewater Treatment Plant WWTP-12: Replace Motors Purpose: Electricity will be saved if inefficient motors are upgraded to NEMA Premium® motors. Scope: Replace the following motors with NEMA Premium® motors. Analysis: This ECO will reduce annual electricity use by 16,200 kWh, electric demand by 33 kW, and energy costs by $1,500. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Motor Construction Maintenance Energy Total Life Cycle Cost CP-1A/CP-1B $1,500 $0 ($3,600) ($2,100) SF-1 $1,200 $0 ($6,400) ($5,200) SF-2 $700 $0 ($1,800) ($1,100) SF-4 $700 $0 ($1,800) ($1,100) RF-1 $1,200 $0 ($6,400) ($5,200) Blowers $6,000 $0 ($7,500) ($1,500) Total $11,300 $0 ($27,500) ($16,200) Note: Negative numbers, in parenthesis, represent savings. WWTP-13: Replace Transformers Purpose: Electricity will be saved if the transformers are replaced with energy efficient models that comply with NEMA Standard TP 1-2001. Scope: Replace 15 kVA and 75 KVA transformers in the generator room with a NEMA Standard TP 1-2001compiant models. Analysis: This ECO will reduce annual electricity use by 21,700 kWh, electric demand by 30 kW, and energy costs by $2,000. The following table summarizes the analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $19,200 $0 ($35,800) ($16,600) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 138 Wastewater Treatment Plant WWTP-14: Boiler Room Heat Recovery Purpose: Heat will be saved if heat from the boiler room is recovered and transferred to the main bay. Scope: Install a heat recovery unit in the boiler room. Install ductwork to circulate boiler room air through one side of the heat recovery cell. Install ductwork to supply the heated air to the main bay and return it. Analysis: The analysis assumes that the boiler loses 1.5% to jacket losses. The HRU is assumed to recover 50% of the heat loss. This ECO will reduce annual fuel oil use by 410 gallons, increase electricity use by 4,100 kWh and 11 kW to operate the fans, with a net energy savings of $590. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $13,000 $2,600 ($24,200) ($8,600) Note: Negative numbers, in parenthesis, represent savings. WWTP-15: Retro-commission Building Purpose: Fuel and electricity will be saved if the building energy systems are optimized through a retro-commissioning process. The energy audit revealed that the building operating sequences are not optimal. Scope: Retro-commission the building with a focus on the following: − Optimize automatic control strategies − Reduce minimum outside air flow − Utilize supply air reset control − Temperature setback of unoccupied rooms − Validate thermostat setpoints Analysis: The analysis conservatively assumes that retro-commissioning will reduce fuel oil use by 4% and electricity use by 0.5% This ECO will reduce annual electricity use by 460 kWh, fuel oil use by 420 gallons and energy costs by $1,200.The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $25,600 $0 ($32,900) ($7,300) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 139 Wastewater Treatment Plant Low Priority Low priority ECOs do not offer a life cycle energy savings and are not recommended. WWTP-16: Variable Speed Heating Pumping Purpose: Electricity will be saved if the hydronic heating system is converted to variable flow pumping. Scope: Install VFDs and NEMA Premium® motors on pumps CP-1 and CP-2. Analysis: The analysis assumes that the average flow rate will be 33% of the peak flow rate. This ECO will reduce annual electricity use by 9,600 kWh, electric demand by 13 kW, and energy costs by $920. The energy savings does not offset the cost of reconfiguring the system, so this ECO is not recommended. The following table summarizes the life cycle cost analysis. Life Cycle Cost Analysis Construction Maintenance Energy Life Cycle Cost $14,600 $2,600 ($16,800) $500 Note: Negative numbers, in parenthesis, represent savings. WWTP-17: Electric Demand Control Purpose: Electricity costs will be reduced if building operators operate the building in a manner that minimizes electric demand charges. Analysis: The electric demand has been very steady. There was one month, July 2008, where the demand jumped by 7 kW. WWTP-18: Seal Ductwork Purpose: Heat and electricity will be saved if the ductwork is sealed against leaks. Analysis: Unsealed ductwork typically has a leakage rate of 5-10% of the airflow. The leakage decreases the ventilation to the rooms and increases heat loss into the ceiling space. Sealing the ductwork will not provide a life cycle savings because of high costs due to the difficulty in accessing existing ducts above ceilings. This ECO is not recommended. Alaska Energy Engineering LLC CBS Energy Audit 140 Wastewater Treatment Plant SUMMARY Energy Analysis The following table shows the projected energy savings of the recommended ECOs. Annual Energy Cost Savings Fuel Oil Electricity Total Current Energy Costs $25,400 $45,000 $70,400 Behavioral and Operational WWTP-1: Turn Off Lighting WWTP-2: Turn Off Equipment WWTP-3: Reduce Hot Water Temperature WWTP-4: Insulate HW Piping WWTP-5: Weather-strip Exterior Doors WWTP-6: Interlock Heaters with Overhead Doors Energy Savings (Estimated) ($130) ($40) ($170) High Priority WWTP-7: Install Water Conserving Aerators $70 ($0) ($70) WWTP-8a: Set Computers to Sleep Mode $0 ($130) ($130) WWTP-8b: Turn Off Inactive Computers $0 ($50) ($50) WWTP-9: Replace Hot Water Recirculating Pump $0 ($290) ($290) Medium Priority WWTP-10: Install Unit Heater Automatic Valves ($440) $0 ($440) WWTP-11: Replace Motors $0 ($1,500) ($1,500) WWTP-12: Replace Transformers $0 ($1,960) ($1,960) WWTP-13: Install Boiler Flue Damper ($390) $0 ($390) WWTP-14: Install Boiler Room Heat Recovery ($980) $400 ($580) WWTP-15: Retro-commission HVAC Systems ($1,010) ($40) ($1,050) ECO Savings ($3,020) ($3,610) ($6,630) (12%) (8%) (9%) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 141 Wastewater Treatment Plant Life Cycle Cost Analysis The following table summarizes the life cycle costs of the recommended ECOs. Life Cycle Cost Analysis Summary Energy Conservation Opportunity Construction Maintenance Energy Total LCC Behavioral and Operational WWTP-1: Turn Off Lighting $0 WWTP-2: Turn Off Equipment $0 WWTP-3: Reduce Hot Water Temperature $100 WWTP-4: Insulate HW Piping $200 WWTP-5: Weather-strip Exterior Doors $1,700 WWTP-6: Interlock Heaters with Overhead Doors $1,500 Totals $3,500 $0 ($4,900) ($1,400) High Priority WWTP-7: Install Water Conserving Aerators $100 $0 ($2,100) ($2,000) WWTP-8a: Set Computers to Sleep Mode $100 $0 ($2,300) ($2,200) WWTP-8b: Turn Off Inactive Computers $100 $0 ($900) ($800) WWTP-9: Replace Hot Water Recirculating Pump $600 $0 ($5,300) ($4,700) Medium Priority WWTP-10: Install Unit Heater Automatic Valves $4,000 $0 ($14,200) ($10,200) WWTP-11: Replace Motors $11,200 $0 ($27,500) ($16,300) WWTP-12: Replace Transformers $19,200 $0 ($35,800) ($16,600) WWTP-13: Install Boiler Flue Damper $6,000 $1,300 ($12,400) ($5,100) WWTP-14: Install Boiler Room Heat Recovery $13,000 $2,600 ($24,100) ($8,500) WWTP-15: Retro-commission HVAC Systems $25,600 $0 ($32,900) ($7,200) Totals $83,400 $3,900 ($162,400) ($75,100) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 142 Wastewater Treatment Plant ENERGY AND LIFE CYCLE COST DATA The following pages contain: • Historic fuel oil consumption • Historic electricity use • Energy and life cycle cost analysis calculations 0 2,000 4,000 6,000 8,000 10,000 0 4,000 8,000 12,000 16,000 20,000 2003 2004 2005 2006 2007 2008 Degree DaysGallonsFuel Oil Consumption Gallons Degree Days Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant ELECTRIC RATE Customer Charge ( $ / mo ) Electricity ($ / kWh )Demand ( $ / kW ) 1-500 kWh $0.1417 First 25 kW $0.00 501-10,000 kWh $0.0903 Over 25 kW $3.90 10,001-100,000 kWh $0.0850 >100,000 kWh $0.0750 ELECTRICAL CONSUMPTION AND DEMAND kWh kW kWh kW kWh kW kWh kW Jan 37,200 86 38,160 91 37,920 96 39,840 96 153,120 Feb 34,320 86 35,520 89 43,200 98 38,400 96 151,440 Mar 35,040 91 31,440 86 35,040 98 43,200 96 144,720 Apr 35,040 86 42,240 91 45,840 91 41,760 91 164,880 May 40,800 89 38,400 91 38,160 91 36,480 91 153,840 Jun 37,680 91 35,760 91 39,360 91 42,480 96 155,280 Jul 32,880 86 41,280 91 35,520 89 40,080 103 149,760 Aug 41,040 89 38,880 89 37,200 89 40,800 91 157,920 Sep 34,320 91 35,520 91 39,120 89 39,360 91 148,320 Oct 38,880 89 43,920 96 37,200 89 37,920 91 157,920 Nov 40,080 89 40,560 96 42,480 91 41,760 91 164,880 D 41 520 91 37 680 91 36 000 91 40 560 96 155 760 August 8, 2009 2008 General Service Month 2005 2006 2007 Average Dec 41,520 91 37,680 91 36,000 91 40,560 96 155,760 Total 448,800 459,360 467,040 482,640 464,460 Average 37,400 89 38,280 91 38,920 92 40,220 94 38,705 Load Factor 57.7% 57.5% 58.0% 58.5% 92 ELECTRIC BILLING DETAILS Month Energy Demand Total Energy Demand Total % Change Jan 3,302 277 3,579 3,465 277 3,742 4.6% Feb 3,751 286 4,037 3,343 277 3,620 -10.3% Mar 3,057 286 3,343 3,751 277 4,028 20.5% Apr 3,975 258 4,233 3,628 258 3,886 -8.2% May 3,322 258 3,580 3,180 258 3,438 -4.0% Jun 3,424 258 3,682 3,690 277 3,966 7.7% Jul 3,098 249 3,347 3,486 305 3,790 13.3% Aug 3,241 249 3,490 3,547 258 3,805 9.0% Sep 3,404 249 3,653 3,424 258 3,682 0.8% Oct 3,241 249 3,490 3,302 258 3,560 2.0% Nov 3,690 258 3,948 3,628 258 3,886 -1.6% Dec 3,139 258 3,397 3,526 277 3,803 12.0% Total $ 40,643 $ 3,136 $ 43,778 $ 41,969 $ 3,239 $ 45,207 3.3% Average $ 3,387 $ 261 $ 3,648 $ 3,497 $ 270 $ 3,767 3.3% Cost ($/kWh) 0.0937 93% 7% 0.0937 -0.1% 2007 2008 Electrical costs are based on the current electric rates. Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWhEnergy Use Comparison 2005 2006 2007 2008 0 20 40 60 80 100 120 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DeckWEnergy Demand Comparison 2005 2006 2007 2008 Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 $ 3,000 $ 3,500 $ 4,000 $ 4,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes $ 0 $ 500 $ 1,000 $ 1,500 $ 2,000 $ 2,500 $ 3,000 $ 3,500 $ 4,000 $ 4,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2008 Energy Cost Breakdown Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes 0 20 40 60 80 100 120 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand (kW)Energy Use (kWh)2008 Energy and Demand Comparison Energy Demand This page intentionally left blank Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant Basis 25 Study Period (years) 3.0% General Inflation 4.1% Nominal Discount Rate 6.0% Fuel Inflation 1.1% Real Discount Rate 1.5% Electricity Inflation Behavioral and Operational Qty Unit Base Cost Year 0 Cost Construction Costs WWTP-1: Turn Off Lighting 1 job $0 $0 WWTP-2: Turn Off Equipment 1 job $0 $0 WWTP-3: Reduce Hot Water Temperature 1 job $100 $100 WWTP-4: Insulate HW Piping 1 job $200 $200 WWTP-5: Weather-strip Exterior Doors 1 job $1,700 $1,700 WWTP-6: Interlock Heaters with Overhead Doors 1 job $1,500 $1,500 Energy Costs Electric Energy 1 - 25 -460 kWh $0.085 ($715) Fuel Oil 1 - 25 -55 gal $2.40 ($4,209) Net Present Worth ($1,424) WWTP-7: Install Water Conserving Aerators Energy Analysis HW Heater Exist GPM New GPM Duration, sec Gal saved Heat, kBTU Boiler Effic Fuel, gals Indirect 2.5 0.5 15 -3,900 -2,602 70% -28 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost August 8, 2009 Use/Day Year 0 0 0 0 30 Year 0 0 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install aerator 4 ea $25 $100 Energy Costs Fuel Oil 1 - 25 -28 gal $2.40 ($2,107) Net Present Worth ($2,007) WWTP-8a: Set Computers to Sleep Mode Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh Factor kWh 5 -125 15 20 -3,738 40% -1,495 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Modify power settings 1 ea $100 $100 Energy Costs Electric Energy 1 - 25 -1,495 kWh $0.0850 ($2,324) Net Present Worth ($2,224) kW -0.6 Year 0 Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 WWTP-8b: Turn Off Inactive Computers Energy Analysis Number Watts Hrs Off, M-F Hrs Off, sa-su kWh 5 -20 15 20 -598 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Modify power settings 1 ea $100 $100 Energy Costs Electric Energy 1 - 25 -598 kWh $0.0850 ($930) Net Present Worth ($830) WWTP-9: Replace Hot Water Recirculating Pump Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh Exist HWRP - - - - -0.4 8,760 -3,504 New HWRP - - - - 0.04 8,760 327 Savings -4 -3,177 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace HWRP 1 ea $600 $600 Energy Costs Electric Energy 1 - 25 -3,177 kWh $0.085 ($4,940) Electric Demand 1 - 25 -4 kW $3.90 ($310) Net Present Worth ($4 650) kW -0.1 Year Year 0 BHP - - 0 Net Present Worth ($4,650) WWTP-10: Install Unit Heater Automatic Valves Energy Analysis Loss, BTUH Number Factor Loss, kBTU Fuel, gals 1,000 10 20% -17,520 -185 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install AV and controls 10 ea $400 $4,000 Energy Costs Fuel Oil 1 - 25 -185 gal $2.40 ($14,188) Net Present Worth ($10,188) Boiler Effic Year 0 70% Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 WWTP-11: Replace Motors Energy Analysis Equip HP η, old ΔkW Hours ΔkWh CP-1A/CP-1B 3.0 81.4% -0.25 8,760 -2,180 SF-1 7.5 85.5% -0.44 8,760 -3,876 SF-2 1.5 79.1% -0.12 8,760 -1,060 SF-4 2.0 80.8% -0.12 8,760 -1,066 RF-1 7.5 85.5% -0.44 8,760 -3,876 Thickened Sludge (2) 15.0 86.6% -0.81 468 -380 Sludge Scum 15.0 86.6% -0.81 208 -169 Clarifier Sludge (3) 3.0 80.0% -0.30 1,643 -488 Clarifier Scum Pit 3.0 80.0% -0.30 52 -15 Grit Pump (2) 7.5 85.5% -0.44 548 -242 Clarifier Dewatering 5.0 83.3% -0.31 15 -5 Water Booster Pump (2) 3.0 81.4% -0.25 312 -78 Recycled Effluent 10.0 80.2% -1.17 312 -364 Blowers 30.0 88.5% -1.38 2,972 -4,095 Lime Pump 5.0 89.5% 0.00 312 0 Filter Press 1.5 79.1% -0.12 312 -38 Auger Monster 5.0 83.3% -0.31 1,460 -453 Rag Screw 2.0 80.8% -0.12 1,460 -178 Upgrade CP-1A/CP-1B Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 2 ea $750 $1,500 Energy Costs η, new 91.7% 89.5% 91.7% 91.7% 89.5% 93.6% 89.5% 86.5% 89.5% 86.5% 92.4% 92.4% 89.5% Year 0 91.7% 86.5% 86.5% 89.5% 89.5% Energy Costs Electric Energy 1 - 25 -2,180 kWh $0.085 ($3,389) Electric Demand 1 - 25 -3 kW $3.90 ($213) Net Present Worth ($2,102) Upgrade SF-1 Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 1 ea $1,175 $1,175 Energy Costs Electric Energy 1 - 25 -3,876 kWh $0.085 ($6,026) Electric Demand 1 - 25 -5 kW $3.90 ($379) Net Present Worth ($5,230) Upgrade SF-2 Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 1 ea $685 $685 Energy Costs Electric Energy 1 - 25 -1,060 kWh $0.085 ($1,648) Electric Demand 1 - 25 -1 kW $3.90 ($104) Net Present Worth ($1,067) Upgrade SF-4 Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 1 ea $675 $675 Energy Costs Electric Energy 1 - 25 -1,066 kWh $0.085 ($1,657) Electric Demand 1 - 25 -1 kW $3.90 ($104) Net Present Worth ($1,086) Year Year 0 Year 0 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 WWTP-11: Replace Motors (continued) Upgrade RF-1 Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 1 ea $1,175 $1,175 Energy Costs Electric Energy 1 - 25 -3,876 kWh $0.085 ($6,026) Electric Demand 1 - 25 -5 kW $3.90 ($379) Net Present Worth ($5,230) Upgrade Blower Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 2 ea $3,000 $6,000 Energy Costs Electric Energy 1 - 25 -4,095 kWh $0.085 ($6,367) Electric Demand 1 - 25 -17 kW $3.90 ($1,179) Net Present Worth ($1,546) Upgrade Thickened Sludge Pump Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 2 ea $1,850 $3,700 Energy Costs Electric Energy 1 - 25 -380 kWh $0.085 ($590) Electric Demand 1 - 25 -10 kW $3.90 ($694) Net Present Worth $2,416 Upgrade Sludge Scum Motor Qty Unit Base Cost Year 0 Cost Year 0 Year 0 Year 0 Year Upgrade Sludge Scum Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 1 ea $1,850 $1,850 Energy Costs Electric Energy 1 - 25 -169 kWh $0.085 ($262) Electric Demand 1 - 25 -10 kW $3.90 ($694) Net Present Worth $893 Upgrade Clarifier Sludge Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 3 ea $750 $2,250 Energy Costs Electric Energy 1 - 25 -488 kWh $0.085 ($758) Electric Demand 1 - 25 -4 kW $3.90 ($254) Net Present Worth $1,238 Upgrade Auger Monster Motor Qty Unit Base Cost Year 0 Cost Construction Costs Replace motor 1 ea $900 $900 Energy Costs Electric Energy 1 - 25 -453 kWh $0.085 ($704) Electric Demand 1 - 25 0 kW $3.90 $0 Net Present Worth $196 Year 0 Year 0 Year 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 WWTP-12: Replace Transformers Energy Analysis KW ηold ηnew kWh 75 94.6% 97.3% -17,739 15 94.0% 97.0% -3,942 -21,681 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Replace 75 KVA transformer 1 ea $13,400 $13,400 Replace 15 KVA transformer 1 ea $5,800 $5,800 Energy Costs Electric Energy 1 - 25 -21,681 kWh $0.085 ($33,708) Electric Demand 1 - 25 -30 kW $3.90 ($2,119) Net Present Worth ($16,627) WWTP-13: Install Boiler Flue Damper Energy Analysis Input, gph FO Gallons On Hours Off Hours CFM w/damper kBTU Boiler Effic Fuel, gals 8.2 11,000 1,343 7,417 4 -15,257 70% -161 15%98.5% Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Install flue damper 2 ea $3,000 $6,000 Annual Costs CFM w/o damper 15 Year 0 -0.45 0 0 KW -2.03 -30 Year Annual Costs Flue damper maintenance 1 - 25 1 hr $60.00 $1,296 Energy Costs Fuel Oil 1 - 25 -161 gal $2.40 ($12,356) Net Present Worth ($5,060) WWTP-14: Install Boiler Room Heat Recovery Energy Analysis Boiler MBH Factor Loss, MBH Factor kBTU Boiler Effic Fuel, gals CFM 1,106 1.5% 17 40% -38,750 70% -410 754 HP η, motor kW Hours 1.0 81.0% 0.9 4,500 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs 750 CFM heat recovery unit 1 ea $6,500 $6,500 Supply and return ductwork 1 ea $3,500 $3,500 Electric and controls 1 ea $3,000 $3,000 Annual Costs HRV maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 4,144 kWh $0.0850 $6,443 Electric Demand 1 - 25 11 kW $3.90 $788 Fuel Oil 1 - 25 -410 gal $2.40 ($31,382) Net Present Worth ($8,557) kWh 4,144 Year 0 0 Recovery, MBH -7 0 Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 alaskaenergy@earthlink.net Wastewater Treatment Plant August 8, 2009 WWTP-15: Retro-commission HVAC Systems Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Develop control sequences 1 ea $4,000 $4,000 Retro-commissioning Modify control drawings 40 hrs $140 $5,600 Modify control software 20 hrs $140 $2,800 On-site Implementation and travel, including commissioning 40 hrs $140 $5,600 Perdiem and Travel 1 ea $2,500 $2,500 Closeout 8 hrs $140 $1,120 Verification 1 ea $4,000 $4,000 Energy Costs Electric Energy 1 - 25 -460 kWh $0.085 ($715) Fuel Oil 1 - 25 -420 gal $2.40 ($32,143) Net Present Worth ($7,238) WWTP-16: Variable Speed Pumping Energy Analysis Pump GPM Head η, pump η, motor kW Hours kWh P-1A/1B -124 53 60% 81.4% -2.5 4,380 -11,114 P-1/2 w/VFD 50 20 60% 89.5% 0.4 4,380 1,538 Savings -13.1 -9,576 Life Cycle Cost Analysis Qty Unit Base Cost Year 0 Cost Construction Costs Year Year 0 0 0 0 0 0 0 BHP -2.8 0.4 Construction Costs VFD + Integration 2 ea $5,400 $10,800 NEMA Premium motors 2 ea $670 $1,340 DDC integration 1 ea $2,500 $2,500 Annual Costs VFD maintenance 1 - 25 2 hrs $60.00 $2,592 Energy Costs Electric Energy 1 - 25 -9,576 kWh $0.0903 ($15,817) Electric Demand 1 - 25 -13 kW $3.90 ($936) Net Present Worth $480 0 0 0 Alaska Energy Engineering LLC CBS Energy Audit 143 Summary Section 10 Summary Energy Conservation Opportunities The following table summarizes the life cycle cost of the ECOs for all the buildings. Energy Conservation Opportunity Summary – 25-year Life Cycle Cost Energy Conservation Opportunity Construction Maintenance Energy Total LCC AIRPORT Behavioral and Operational Airport-1: Turn Off Lighting $0 Airport-2: Turn Off Equipment $0 Airport-3: Adjust SF-1 Outside Air Damper $0 Airport-4: Increase Boiler Room Temperature $50 Airport-5: Reduce Entrance Temperatures $100 Airport-6: Adjust Entrance Auto Door Closures $150 Airport-7: Replace Boiler Thermostat $200 Airport-8: Weather-strip Jetway Windows $600 Airport-9: Weather-strip Exterior Doors $1,400 Airport-10: Seal Baggage Belt Openings $ 7,500 Totals $10,000 $0 ($12,600) ($2,600) High Priority Airport-11: Turn Off SF-3 $200 ($5,800) ($22,200) ($27,800) Airport-12a: Set Computers to Sleep Mode $100 $0 ($2,000) ($1,900) Airport-12b: Turn Off Inactive Computers $200 $0 ($1,300) ($1,100) Airport-13: Install Unit Heater Auto Valves $1,200 $0 ($8,000) ($6,800) Airport-14: Install Boiler Flue Damper $3,000 $1,300 ($10,200) ($5,900) Medium Priority Airport-15: Install TSA Natural Cooling System $9,500 ($3,900) ($46,600) ($41,000) Airport-16: Retro-commission HVAC Systems $25,000 $0 ($97,500) ($72,500) Airport-17: Install Refrigeration Heat Recovery $7,500 $2,600 ($30,600) ($20,500) Airport-18: Install Jetway Occupancy Sensors $4,000 ($400) ($12,300) ($8,700) Airport-19: Replace Main Entrance Glazing $15,900 $0 ($32,100) ($16,200) Airport-20: Replace Jetway Windows $1,700 $0 ($2,700) ($1,000) Airport-21: Replace Transformers $7,500 $0 ($11,700) ($4,200) Airport-22: Variable Hold Room Air Flow $11,800 $2,600 ($15,200) ($800) Airport Totals $97,600 ($3,600) ($305,000) ($211,000) Alaska Energy Engineering LLC CBS Energy Audit 144 Summary Energy Conservation Opportunity Summary – 25-year Life Cycle Cost (continued) Energy Conservation Opportunity Construction Maintenance Energy Total LCC CENTENNIAL BUILDING Behavioral and Operational Centennial-1: Close Auditorium Drapes $0 Centennial-2: Turn Off Lighting $0 Centennial-3: Reduce Entrance Temperatures $100 Centennial-4: Turn Off Redundant HW Heater $100 Centennial-5: Interlock Pumps $100 Centennial-6: Seal Exhaust Duct $200 Centennial-7: Replace Boiler Thermostat $400 Centennial-8: Seal Chimney Roof Penetration $400 Centennial-9: Insulate Boiler Combustion Air Duct $400 Centennial-10: Weather-strip Exterior Doors $1,200 Totals $2,900 $0 ($22,300) ($19,400) High Priority Centennial-11: Install Water Conserving Aerators $200 $0 ($14,800) ($14,600) Centennial-12: Reduce Exterior Lighting $200 ($3,700) ($15,100) ($18,600) Centennial-13: Install CUH Automatic Valves $800 $0 ($4,300) ($3,500) Centennial-14a: Set Computers to Sleep Mode $200 $0 ($900) ($700) Centennial-14b: Turn Off Inactive Computers $200 $0 ($600) ($400) Medium Priority Centennial-15: Meeting Room Optimization Analysis $7,500 n/a n/a $7,500 Centennial-16: Replace HVAC Motors $2,500 $0 ($5,600) ($3,100) Centennial-17: Install Boiler Room Heat Recovery $15,500 $2,600 ($36,000) ($17,900) Centennial-18: Install Boiler Flue Damper $6,000 $1,300 ($11,300) ($4,000) Centennial-19: Retro-commission HVAC Systems $31,700 $0 ($50,300) ($18,600) Centennial Building Totals $67,700 $200 ($161,200) ($93,300) CITY HALL Behavioral and Operational $300 $0 ($5,400) ($5,100) City Hall-1: Turn Off Heaters $0 City Hall-2: Turn Off Lighting $0 City Hall-3: Turn Off Equipment $0 City Hall-4: Weather-strip Exterior Doors $300 Totals $300 $0 ($5,400) ($5,100) High Priority City Hall-5: Water Conserving Aerators $200 $0 ($6,700) ($6,500) City Hall-6a: Set Computers to Sleep Mode $500 $0 ($13,100) ($12,600) City Hall-6b: Turn Off Inactive Computers $500 $0 ($8,400) ($7,900) Medium Priority City Hall-7: Install a VFD on AHU-1 $7,300 $4,300 ($23,400) ($11,800) City Hall-8: Install HW Heater Demand Control $1,500 $0 ($2,300) ($800) City Hall-9: Computer Room Natural Cooling $7,500 ($3,900) ($6,000) ($2,400) City Hall-10: Install Lighting Occ. Sensors $12,000 $1,300 ($15,600) ($2,200) City Hall-11: Replace Main Entrance Doors $10,100 $0 ($10,500) ($400) City Hall Totals $39,900 $1,700 ($91,400) ($49,800) Alaska Energy Engineering LLC CBS Energy Audit 145 Summary Energy Conservation Opportunity Summary – 25-year Life Cycle Cost (continued) Energy Conservation Opportunity Construction Maintenance Energy Total LCC FIRE HALL Behavioral and Operational Fire Hall-1: Turn Off Lighting $0 Fire Hall-2: Turn Off Equipment $0 Fire Hall-3: Replace Boiler Thermostat $400 Fire Hall-4: Provide Overhead Door Controls $3,400 Totals $3,800 $0 ($4,400) ($600) High Priority Fire Hall-6: Implement Apparatus Bay Light Control $200 ($8,600) ($55,900) ($64,300) Fire Hall-7: Install Water Conserving Aerators $200 $0 ($3,900) ($3,700) Fire Hall-8: Install Water Conserving Showerheads $200 $0 ($2,200) ($2,000) Fire Hall-9a: Set Computers to Sleep Mode $200 $0 ($2,500) ($2,300) Fire Hall-9b: Turn Off Inactive Computers $200 $0 ($1,600) ($1,400) Fire Hall-10: Install Unit Heater Automatic Valves $800 $0 ($4,300) ($3,500) Medium Priority Fire Hall-11: Install Boiler Flue Damper $4,000 $1,300 ($10,600) ($5,300) Fire Hall-12: Install Boiler Room Heat Recovery $15,500 $2,600 ($32,900) ($14,800) Fire Hall-13: Retro-commission HVAC Systems $24,200 $0 ($48,900) ($24,700) Fire Hall-14: Increase Roof Insulation $14,900 $0 ($20,900) ($6,000) Fire Hall Totals $64,200 ($4,700) ($188,200) ($128,700) LIBRARY Behavioral and Operational Library-1: Turn Off Equipment $0 Library-2: Interlock Pump P-3 $100 Library-3: Replace Workroom Lockset $200 Library-4: Replace Boiler Thermostat $200 Library-5: Weather-strip Exterior Doors $500 Totals $1,000 $0 ($1,800) ($800) High Priority Library-6a: Set Computers to Sleep Mode $200 $0 ($5,400) ($5,200) Library-6b: Turn Off Inactive Computers $200 $0 ($3,500) ($3,300) Library-7: Water Conserving Aerators $100 $0 ($1,200) ($1,100) Library-8: Boiler Flue Damper $2,000 $600 ($6,000) ($3,300) Medium Priority Library-9: Boiler Room Heat Recovery $11,000 $2,600 ($17,200) ($3,600) Library-10: Retro-commission HVAC Systems $19,600 $0 ($24,600) ($5,000) Library-11: Replace Entrance Glazing $4,900 $0 ($5,800) ($900) Library Totals $39,000 $3,200 ($65,400) ($23,200) Alaska Energy Engineering LLC CBS Energy Audit 146 Summary Energy Conservation Opportunity Summary – 25-year Life Cycle Cost (continued) Energy Conservation Opportunity Construction Maintenance Energy Total LCC PUBLIC SERVICES OFFICE/SHOP Behavioral and Operational PSC-1: Turn Off Lighting $0 PSC-2: Turn Off Equipment $0 PSC-3: Close Inner Entrance Doors $0 PSC-4: Reduce Entrance Temperature $100 PSC-5: Replace Boiler Thermostat $200 PSC-6: Decommission Ventilation Systems $500 PSC-7: Repair Duct Insulation $500 PSC-8: Weather-strip Exterior Doors $800 PSC-9: Interlock Heaters with Overhead Doors $2,500 Totals $4,600 $0 ($6,200) ($1,600) High Priority PSC-10: Water Conserving Aerators $200 $0 ($2,500) ($2,300) PSC-11a: Set Computers to Sleep Mode $500 $0 ($7,600) ($7,100) PSC-11b: Turn Off Inactive Computers $500 $0 ($4,900) ($4,400) Medium Priority PSC-12: Unit Heater Automatic Valves $6,000 $0 ($21,300) ($15,300) PSC-13: Install Boiler Room Heat Recovery $16,500 $2,600 ($32,100) ($13,000) PSC-14: Install Boiler Flue Damper $6,000 $1,300 ($11,400) ($4,100) PSC-15: Retro-commission HVAC Systems $25,400 $0 ($37,600) ($12,100) PSC-16: Install Lighting Occupancy Sensors $6,500 $1,300 ($8,800) ($1,000) Public Services Office/Shop Totals $66,200 $5,200 ($132,400) ($61,000) SENIOR CENTER Behavioral and Operational Senior Center-1: Turn Off Lighting $0 Senior Center-2: Turn Off Equipment $0 Senior Center-3: Reduce Entrance Temperature $100 Senior Center-4: Insulate HW Piping $200 Senior Center-5: Weather-strip Doors $500 Senior Center-6: Reduce Refrigeration $500 Senior Center-7: Replace Thermostats $1,800 Senior Center-8: Increase Duct Insulation $5,000 Totals $8,100 $0 ($14,800) ($6,700) Top Priority Senior Center-9: Reduce Dining Room Lighting $300 ($700) ($6,700) ($7,100) Senior Center-10: Install Water Conserving Aerators $200 $0 ($3,300) ($3,100) Senior Center-11a: Set Computers to Sleep Mode $100 $0 ($1,300) ($1,200) Senior Center-11b: Turn Off Inactive Computers $100 $0 ($400) ($300) Medium Priority Senior Center-12: Install Refrig. Heat Recovery $9,500 $2,600 ($23,500) ($11,400) Senior Center-13: Install HW Heater Demand Controls $1,500 $0 ($3,200) ($1,700) Senior Center-14: Replace Entrance Doors $3,000 $0 ($3,500) ($500) Senior Center Totals $22,700 $1,900 ($56,700) ($32,100) Alaska Energy Engineering LLC CBS Energy Audit 147 Summary Energy Conservation Opportunity Summary – 25-year Life Cycle Cost (continued) Energy Conservation Opportunity Construction Maintenance Energy Total LCC WASTEWATER TREATMENT PLANT (WWTP) Behavioral and Operational WWTP-1: Turn Off Lighting $0 WWTP-2: Turn Off Equipment $0 WWTP-3: Reduce Hot Water Temperature $100 WWTP-4: Insulate HW Piping $200 WWTP-5: Weather-strip Exterior Doors $1,700 WWTP-6: Interlock Heaters with Overhead Doors $1,500 Totals $3,500 $0 ($4,900) ($1,400) High Priority WWTP-7: Install Water Conserving Aerators $100 $0 ($2,100) ($2,000) WWTP-8a: Set Computers to Sleep Mode $100 $0 ($2,300) ($2,200) WWTP-8b: Turn Off Inactive Computers $100 $0 ($900) ($800) WWTP-9: Replace Hot Water Recirculating Pump $600 $0 ($5,300) ($4,700) Medium Priority WWTP-10: Install Unit Heater Automatic Valves $4,000 $0 ($14,200) ($10,200) WWTP-11: Replace Motors $11,200 $0 ($27,500) ($16,300) WWTP-12: Replace Transformers $19,200 $0 ($35,800) ($16,600) WWTP-13: Install Boiler Flue Damper $6,000 $1,300 ($12,400) ($5,100) WWTP-14: Install Boiler Room Heat Recovery $13,000 $2,600 ($24,100) ($8,500) WWTP-15: Retro-commission HVAC Systems $25,600 $0 ($32,900) ($7,200) Wastewater Treatment Plant Totals $83,400 $3,900 ($162,400) ($75,100) SUMMARY Airport $97,600 ($3,600) ($305,000) ($211,000) Centennial Building $67,700 $200 ($161,200) ($93,300) City Hall $39,900 $1,700 ($91,400) ($49,800) Fire Hall $64,200 ($4,700) ($188,200) ($128,700) Library $39,000 $3,200 ($65,400) ($23,200) Public Services Office/Shop $66,200 $5,200 ($132,400) ($61,000) Senior Center $22,700 $1,900 ($56,700) ($32,100) Wastewater Treatment Plant $83,400 $3,900 ($162,400) ($75,100) Total $480,700 $7,800 ($1,162,700) ($674,200) Note: Negative numbers, in parenthesis, represent savings. Alaska Energy Engineering LLC CBS Energy Audit 148 Summary Energy Savings The following table shows the estimated energy savings if all of the ECOs are implemented. The report provides a breakdown of the savings associated with each ECO. Annual Energy Cost Savings Summary Existing Energy Cost ECO Savings % Airport $88,000 ($11,000) (13%) Centennial Building $43,000 ($5,400) (12%) City Hall $36,000 ($5,000) (14%) Fire Hall $42,000 ($7,200) (17%) Library $19,000 ($2,200) (12%) Public Services Office/Shop $25,000 ($4,600) (19%) Senior Center $14,000 ($3,100) (22%) Wastewater Treatment Plant $70,000 ($6,600) (9%) Totals $337,000 ($45,100) (13%) Note: Negative numbers, in parenthesis, represent savings. Conclusion The energy systems in the CBS buildings are in good condition and appear to be well maintained. The outstanding exceptions are the control systems at City Hall and the Senior Center which have reached the end of their services lives and are not providing efficient control. It is recommended that the control systems be replaced in the near future to take full advantage of the resulting energy savings. The energy auditor would like to express appreciation to CBS operation and maintenance personnel and building staff that provided assistance during this project. Their knowledge of the building energy systems and interest in energy efficiency was invaluable.