HomeMy WebLinkAboutAttachment 9 - CBS Energy 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
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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 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
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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
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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
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2008 Energy Cost Breakdown
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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.