HomeMy WebLinkAboutSEA-AEE-JNU Douglas Parks and Recreation Shop 2012-EE
Douglas Parks and Recreation Shop
City and Borough of Juneau
Funded by:
Final Report
October 2011
Prepared by:
Energy Audit
Table of Contents
Section 1: Executive Summary 2
Section 2: Introduction 5
Section 3: Energy Efficiency Measures 8
Section 4: Description of Systems 15
Section 5: Methodology 17
Appendix A: Energy and Life Cycle Cost Analysis 20
Appendix B: Energy and Utility Data 26
Appendix C: Equipment Data 33
Appendix D: Abbreviations 35
Audit Team
The energy audit is performed by Alaska Energy Engineering LLC of Juneau, Alaska. The audit team
consists of:
Jim Rehfeldt, P.E., Energy Engineer
Jack Christiansen, Energy Consultant
Brad Campbell, Energy Auditor
Loras O’Toole P.E., Mechanical Engineer
Will Van Dyken P.E., Electrical Engineer
Curt Smit, P.E., Mechanical Engineer
Philip Iverson, Construction Estimator
Karla Hart, Technical Publications Specialist
Jill Carlile, Data Analyst
Grayson Carlile, Energy Modeler
Douglas Parks and Recreation Shop 1 FINAL Energy Audit (October 2011)
Section 1
Executive Summary
An energy audit of the Douglas Parks and Recreation Shop was performed by Alaska Energy
Engineering LLC. The investment grade audit was funded by Alaska Housing Finance Corporation
(AHFC) to identify opportunities to improve the energy performance of public buildings throughout
Alaska.
The Douglas Parks and Recreation Shop is an 8,742 square foot building that contains offices,
maintenance bays, and storage areas for support of the Parks and Recreation Department.
Building Assessment
The following summarizes our assessment of the building.
Envelope
Much of the building envelope has been upgraded to current standards. The exception is the recently
installed double pane windows which are less optimal than triple pane windows. There is no
economic incentive to upgrade the windows.
The man doors are not thermally broken which causes them to conduct heat through the skin to the
outdoors. Unfortunately, there is no economic incentive to replace them. The overhead doors are good
quality doors.
The building perimeter and floor slab are not insulated, which was the standard when the building
was constructed. There is no economical way to add insulation.
Heating System
The fuel oil boiler heating system is in good condition. The relatively low heating load offers little
incentive to invest in alternatives to fuel oil.
Ventilation System
The building ventilation systems consist of toilet room exhaust fans. The toilet exhaust fans are
controlled from the light switch, which is less optimal than using an occupancy sensor with a delay
timer to purge the air.
Lighting
The lighting has not been upgraded from the original construction. Lighting upgrades are not
recommended because an analysis determined the majority of that fixture heat is useful toward
heating the building.
Equipment
Computers are continuously on, albeit in sleep mode when they are not in active use. Turning them
off will reduce electric costs and conserve valuable hydroelectric resources.
In addition, the audit team noted that there are no carbon monoxide sensors installed in the
maintenance bays to warn of high CO levels.
Douglas Parks and Recreation Shop 2 FINAL Energy Audit (October 2011)
Energy Efficiency Measures (EEMs)
All buildings have opportunities to improve their energy efficiency. The energy audit revealed
numerous opportunities in which an efficiency investment will result in a net reduction in long-term
operating costs.
Behavioral and Operational EEMs
The following EEMs require behavioral and operational changes in the building use. The savings are
not readily quantifiable but these EEMs are highly recommended as low-cost opportunities that are a
standard of high performance buildings.
EEM-1: Weather-strip Doors and Windows
EEM-2: Utilize Split Level Switching
EEM-3: Relocate Electric Heater
EEM-4: Install Automatic Overhead Door Openers
EEM-5: Clean Lint from Dryer Outlet
EEM-6: Replace Appliances with Energy Star Models
EEM-7: Reduce Domestic Hot Water Heater Size
High and Medium Priority EEMs
The following EEMs are recommended for investment. They are ranked by life cycle savings to
investment ratio (SIR). This ranking method places a priority on low cost EEMs which can be
immediately funded, generating energy savings to fund higher cost EEMs in the following years.
Negative values, in parenthesis, represent savings.
Life Cycle Cost Analysis
Investment Operating Energy Total SIR
High Priority EEMs
EEM-8: Adjust Boiler Thermostat $100 $0 ($7,300) ($7,200) 73.0
EEM-9: Change Electric Rate $100 $0 ($7,300) ($7,200) 73.0
EEM-10: Install Pipe Insulation $300 $0 ($3,600) ($3,300) 12.0
EEM-11: Turn Off Computers $100 $0 ($1,000) ($900) 10.0
EEM-12: Insulate Office Floor $700 $0 ($5,400) ($4,700) 7.7
EEM-13: Perform Boiler Combustion Test $700 $2,300 ($7,300) ($4,300) 7.1
EEM-14: Replace Aerators $200 $0 ($1,400) ($1,200) 7.0
EEM-15: Install Valves on Unit Heaters $2,000 $0 ($8,100) ($6,100) 4.1
Medium Priority EEMs
EEM-16: Install Boiler Room Heat Recovery $8,500 $4,600 ($27,100) ($14,000) 2.6
EEM-17: Interlock Heaters with Overhead Doors $8,000 $0 ($18,300) ($10,300) 2.3
EEM-18: Install Instantaneous HW Heater $1,500 $0 ($1,300) $200 0.9
EEM-19: Install Water-Conserving Fixtures $4,300 $0 ($1,100) $3,200 0.3
Total* $26,500 $6,900 ($89,200) ($55,800) 2.7
* The analysis is based on each EEM being independent of the others. While it is likely that some
EEMs are interrelated, an isolated analysis is used to demonstrate the economics because the audit
team is not able to predict which EEMs an Owner may choose to implement. If several EEMs are
implemented, the resulting energy savings is likely to differ from the sum of each EEM projection.
Douglas Parks and Recreation Shop 3 FINAL Energy Audit (October 2011)
Summary
The energy audit revealed numerous opportunities for improving the energy performance of the
building. It is recommended that the behavioral and high priority EEMs be implemented now to
generate energy savings from which to fund the medium priority EEMs.
Another avenue to consider is to borrow money from AHFCs revolving loan fund for public
buildings. AHFC will loan money for energy improvements under terms that allow for paying back
the money from the energy savings. More information on this option can be found online at
http://www.ahfc.us/loans/akeerlf_loan.cfm.
Douglas Parks and Recreation Shop 4 FINAL Energy Audit (October 2011)
Section 2
Introduction
This report presents the findings of an energy audit of the Douglas Parks and Recreation Shop located
in Douglas, Alaska. The purpose of this investment grade energy audit is to evaluate the infrastructure
and its subsequent energy performance to identify applicable energy efficiencies measures (EEMs).
The energy audit report contains the following sections:
Introduction: Building use and energy consumption.
Energy Efficiency Measures: Priority ranking of the EEMs with a description, energy analysis,
and life cycle cost analysis.
Description of Systems: Background description of the building energy systems.
Methodology: Basis for how construction and maintenance cost estimates are derived and the
economic and energy factors used for the analysis.
BUILDING USE
The Douglas Parks and Recreation Shop is an 8,742 square foot building that contains offices,
maintenance bays, and storage areas for support of the Parks, Recreation, and Landscaping
operations. The building is used in the following manner:
Summer Use: The building has up to 30 occupants with most of the staff in the field throughout
the day. Offices are used Monday thru Friday during normal working hours, and as needed on
weekends and holidays. Maintenance bays are used intermittently 7-days a week.
Winter Use: The building has up to 5 office occupants. Offices are used Monday thru Friday
during normal working hours. Maintenance bays are used occasionally in support of operations.
History
Energy efficiency changes to the building include:
1967 – Original construction
1989 – Heating plant replacement
2005 – Roof replacement
2007 – Siding replacement
Douglas Parks and Recreation Shop 5 FINAL Energy Audit (October 2011)
Energy and Water Consumption
The building energy sources include an electric service and a fuel oil tank. Fuel oil is used for the
majority of the heating loads while electricity serves all other loads, including domestic hot water and
a limited amount of space heating. The following table shows annual energy use and cost.
Annual Energy Consumption and Cost
Source Consumption Cost Energy, MMBtu
Electricity 37,798 kWh $3,500 129 11%
Fuel Oil 7,453 Gallons $25,500 1,012 89%
Totals - $29,000 1,141 100%
Electricity
The following chart shows electrical energy use from 2007 to 2010. Electricity use dropped in May
2008 when electric rates increased temporarily due to an avalanche. The avalanche disrupted power
from Juneau’s primary hydroelectric generation facility, causing the utility to generate power with
more expensive diesel generators. Conservation efforts put into effect after the avalanche have caused
post-avalanche use to be less. There has been a slight upward trend in energy use but the use is still
considerably below pre-avalanche levels.
The large increase in consumption that occurred in July-September of 2010 is unexplained.
The effective cost—energy costs plus demand charges—is 13.5¢ per kWh.
Douglas Parks and Recreation Shop 6 FINAL Energy Audit (October 2011)
Fuel Oil
The following chart shows heating energy use from 2007 to 2010. The chart compares annual use
with the heating degree days which is a measurement of the demand for energy to heat a building. A
year with a higher number of degree days reflects colder outside temperatures and a higher heating
requirement.
Variations in annual fuel oil use reflect higher heat loss in 2007 while the roof and siding was
upgraded and then a reduction in consumption.
The current cost of fuel oil (August 2011) is $3.23 per gallon. Assuming a fuel oil conversion
efficiency of 70% and an electric boiler conversion efficiency of 95%, oil heat at $3.23 per gallon
equates to electric heat at 10.8¢ per kWh. Since the current cost of electricity is 13.5¢ per kWh, fuel
oil heat is currently less expensive than electric heat.
Water
Water consumption averages 72,000 gallons per year. The water use is metered but the cost is a fixed
rate per month.
Douglas Parks and Recreation Shop 7 FINAL Energy Audit (October 2011)
Section 3
Energy Efficiency Measures
The following energy efficiency measures (EEMs) were identified during the energy audit. The
EEMs are priority ranked and, where applicable, subjected to energy and life cycle cost analysis.
Appendix B contains the energy and life cycle cost analysis spreadsheets.
The EEMs will be grouped into the following prioritized categories:
Behavioral or Operational: EEMs that require minimal capital investment but require operational
or behavioral changes. The EEMs provide a life cycle savings but an analysis is not performed
because the guaranteed energy savings is difficult quantify.
High Priority: EEMs that require a small capital investment and offer a life cycle savings. Also
included in this category are higher cost EEMs that offer significant life cycle savings.
Medium Priority: EEMs that require a significant capital investment to provide a life cycle
savings. Many medium priority EEMs provide a high life cycle savings and offer substantial
incentive to increase investment in building energy efficiency.
Low Priority: EEMs that will save energy but do not provide a life cycle savings.
BEHAVIORAL OR OPERATIONAL
The following EEMs are recommended for implementation. They require behavioral or operational
changes that can occur with minimal investment to achieve immediate savings. These EEMs are not
easily quantified by analysis because they cannot be accurately predicted. They are recommended
because they offer a life cycle savings, represent good practice, and are accepted features of high
performance buildings.
EEM-1: Weather-strip Doors and Windows
Purpose: Energy will be saved if doors and windows are properly weather-stripped to reduce
infiltration. The exterior man doors do not have weather-stripping. The West overhead
door weather-stripping is damaged and incomplete.
Scope: Replace west overhead door weather-stripping with a product similar to the south
overhead doors, and install weather- stripping on man doors.
EEM-2: Utilize Split Level Switching
Purpose: Split level switching provides the opportunity to turn on only a portion of the lights in a
space. The maintenance bays have numerous lighting zones – each with their own
switch.
Scope: Develop a procedure for lighting the maintenance bays with a limited number of
fixtures in each zone to provide adequate lighting levels for circulation.
Douglas Parks and Recreation Shop 8 FINAL Energy Audit (October 2011)
EEM-3: Relocate Electric Heater
Purpose: The men’s room lighting and exhaust fan are controlled together from the same space
occupancy sensor. An electric heater is located immediately adjacent to the bathroom
exhaust fan. When the space is occupied, the exhaust fan is discharging warm air from
the heater directly outside.
Scope: Move the unit heater to a more efficient location
EEM-4: Install Automatic Overhead Door Openers
Purpose: When vehicles leave the maintenance shop, they have no means of quickly closing the
overhead doors. As a result, the doors are often left open for an extended period of
time. With remote controls, the doors can be closed immediately. Energy will be
saved if the overhead door can be shut by remote control.
Scope: Interlock truck remote controls in the trucks so operators can close the overhead doors.
EEM-5: Clean Lint from Dryer Outlet
Purpose: Cleaning the exhaust duct will increase efficiency of dryer operations.
Scope: Clean lint from dryer outlet.
EEM-6: Replace Appliances with Energy Star Models
Purpose: Energy Star appliances are the standard for high performance buildings. The building
has a few appliances that are not Energy Star compliant.
Scope: When appliances reach the end of their service life, replace them with Energy Star
compliant models.
EEM-7: Reduce Domestic Hot Water Heater Size
Purpose: The maintenance shop domestic hot water heater is a 50 gallon unit, and has a very
limited demand. Reducing the size of the domestic hot water heater to a 20 gallon unit
would reduce electrical consumption while still providing a sufficient recovery rate.
Scope: When the existing heater fails, replace it with a 20 gallon unit.
Douglas Parks and Recreation Shop 9 FINAL Energy Audit (October 2011)
HIGH PRIORITY
The following EEMs are recommended for implementation because they are low cost measures that
have a high savings to investment ratio. The EEMs are listed from highest to lowest priority. Negative
values, in parenthesis, represent savings.
EEM-8: Adjust Boiler Thermostat
Purpose: Energy 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 an adjustable
differential between on and off setpoints. Setting it to 30°F differential will increase the
amount of time the boiler operates each cycle, which improves seasonal efficiency.
Scope: Adjust the boiler thermostat differential as large as possible without compromising
heating performance. As a starting point, use differentials of 30°F in the winter and
40°F in the summer.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($260) ($260) $100 $0 ($7,300) ($7,200) 73.0
EEM-9: Change Electric Rate
Purpose: The building is currently being billed under AEL&Ps ‘small commercial rate with
demand charges’. The CBJ has the option of being billed the ‘small commercial rate
without demand charges’. Analysis of past electric bills indicates the electric charges
will be lower with the ‘small commercial rate without demand charges’.
Scope: Contact AEL&P and change to the ‘small commercial rate without demand’ rate.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($420) ($420) $100 $0 ($7,300) ($7,200) 73.0
EEM-10: Install Pipe Insulation
Purpose: Energy will be saved if the heating piping is optimally insulated. A section of heating
piping in the tire storage area and the heating piping adjacent to the middle
maintenance bay heating unit are uninsulated.
Scope: Install insulation on uninsulated heating piping.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($130) ($130) $300 $0 ($3,600) ($3,300) 12.0
Douglas Parks and Recreation Shop 10 FINAL Energy Audit (October 2011)
EEM-11: Turn Off Computer Equipment
Purpose: There are six computer stations, three printers, and one fax machine in the Douglas
Shop. Energy will be saved if this equipment is turned off when 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 EEM requires
behavioral changes where occupants turn off equipment when they are finished.
The justification for leaving computers on is so networks can update software and
perform backups. There are computer programs designed to turn on computers to
perform these tasks and them turn them off. In addition, the software can start
computers in the morning so they are available when people return to work.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($60) ($60) $100 $0 ($1,000) ($900) 10.0
EEM-12: Insulate Office Floor
Purpose: The shop maintenance bays are operated at a lower temperature than the office spaces.
A 20’ x 21’ section of the office floor above the middle maintenance bay is not
insulated. This results in heat loss from the office to the maintenance bays. While
some of this heat loss is beneficial to the maintenance bays, a percentage of it is wasted
heat.
Scope: Install a minimum of R-21 insulation in this space.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($190) ($190) $700 $0 ($5,400) ($4,700) 7.7
EEM-13: Perform a Boiler Combustion Test
Purpose: Operating the boiler with an optimum amount of excess air will improve combustion
efficiency. Annual cleaning followed by a combustion test is recommended.
Scope: Annually clean and perform a combustion test on the boiler.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$120 ($260) ($140) $700 $2,300 ($7,300) ($4,300) 7.1
Douglas Parks and Recreation Shop 11 FINAL Energy Audit (October 2011)
EEM-14: Replace Aerators
Purpose: Energy and water will be saved by replacing the aerators on the sinks, lavatories, and
showerheads with low-flow models.
Scope: Replace aerators on sinks, lavatories, and showerheads with water-conserving fixtures.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($80) ($80) $200 $0 ($1,400) ($1,200) 7.0
EEM-15: Install Automatic Valves on Unit Heaters
Purpose: Energy will be saved if each unit heater has an automatic valve that shuts off the
heating flow when heat is not needed. Currently, the coils in the unit heaters are
continuously hot and the thermostat turns on the fan to supply the heat to the room.
When heat is not needed, convective heat loss from the coil occurs; some of the heat
loss may be useful, but a large percentage is not.
Scope: Install automatic valves in the heating supply to each unit heater and control them from
the fan thermostat.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($290) ($290) $2,000 $0 ($8,100) ($6,100) 4.1
MEDIUM PRIORITY
Medium priority EEMs require planning and a higher level of investment. They are recommended
because they offer a life cycle savings. The EEMs are listed from highest to lowest priority. Negative
values, in parenthesis, represent savings.
EEM-16: Install Boiler Room Heat Recovery
Purpose: The boiler has considerable jacket losses. Energy will be saved if this “waste” heat is
recovered from the boiler room and transferred to the maintenance 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 maintenance bay.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$240 ($890) ($650) $8,500 $4,600 ($27,100) ($14,000) 2.6
Douglas Parks and Recreation Shop 12 FINAL Energy Audit (October 2011)
EEM-17: Interlock Heaters with Overhead Doors
Purpose: When overhead doors are opened, a considerable amount of heat escapes out the
opening. Interlocking the heaters so they turn off while the doors are open will reduce
heat loss, especially on occasions where the doors are left open for long periods.
Scope: Interlock the heaters with overhead doors so heaters are off when doors are open.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($650) ($650) $8,000 $0 ($18,300) ($10,300) 2.3
LOW PRIORITY
Low priority EEMs do not offer a life cycle energy savings and are not recommended.
EEM-18: Install Instantaneous HW Heater
Purpose: The hot water heater in the men’s restroom on the first floor distributes hot water to
several adjacent fixtures and to the break room in the upstairs office at the east end of
the building. The proposed modification installs an instantaneous hot water heater for
the breakroom sink to reduce distribution heat loss.
Scope: Install an instantaneous hot water heater at the break room sink.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($50) ($50) $1,500 $0 ($1,300) $200 0.9
EEM-19: Install Water-Conserving Fixtures
Purpose: Water will be saved by replacing the plumbing fixtures with water-conserving fixtures.
Scope: Replace toilets and urinals with water-conserving fixtures.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($60) ($60) $4,300 $0 ($1,100) $3,200 0.3
EEM-20: Increase Perimeter Insulation
Purpose: The perimeter foundation walls are uninsulated. The current optimal level is 3” thick
insulation. Energy will be saved by adding perimeter insulation.
Scope: Install perimeter insulation against the outside foundation wall.
Analysis: Previous analyses have shown that that adding insulation to the perimeter footings will
not provide a life cycle savings.
Douglas Parks and Recreation Shop 13 FINAL Energy Audit (October 2011)
EEM-21: Replace Windows
Purpose: Energy will be saved by replacing the existing windows with more energy efficient
units. Triple pane windows are now the standard for modern high efficiency buildings.
The existing windows have an insulation value of R-2. Replacement windows have an
insulation value of R-5.
Scope: Replace the existing windows with vinyl triple pane windows.
Analysis: Previous analyses have shown that replacing double pane windows with triple pane
windows will not provide a life cycle savings.
EEM-22: Replace Doors
Purpose: The existing man doors do not have thermally broken frames and doors. This allows
the door to conduct heat through the door to the outside. Energy will be saved if the
non-thermally broken doors are replaced with thermally broken units.
Scope: Replace existing man doors with thermally broken man doors.
Analysis: Previous analyses have shown that replacing non-thermally broken doors with
thermally broken doors will not provide a life cycle savings.
EEM-23: Reduce Boiler Size
Purpose: The existing boiler is approximately 200% the required size for the building. The
recent envelope upgrades are likely the reason for it being much too large. Installing a
smaller boiler will improve the heating system efficiency by 3-5%.
Scope: Replace boiler with properly sized unit.
Analysis: Previous analyses have shown that replacing the oversized boiler with a properly sized
unit will not provide a life cycle savings.
Douglas Parks and Recreation Shop 14 FINAL Energy Audit (October 2011)
Section 4
Description of Systems
ENERGY SYSTEMS
This section provides a general description of the building systems. Energy conservation
opportunities are addressed in the Energy Efficiency Measure section of the report.
Building Envelope
The following table summarizes the existing envelope.
Building Envelope
R-value
Component Description (inside to outside) Existing Optimal
Exterior Walls
Office Gyp. Bd; 2x4 wd studs with R-11 batt; foam insulated wall panel R-30 R-26
Maintenance Foam insulated wall panel R-21 R-26
Interior Walls (between offices and maintenance bays)
Office Gyp. Bd; 2x4 wd studs with R-11 batt; gyp.bd. R-11 R-11
Roof Foil clad batt insulation; metal roof; 12” batt; metal roof R-40 R-46
Interior Floor (between office and maintenance bay)
Office Floor covering; sheathing; floor joists R-3 R-11
Floor Slab Concrete slab-on-grade R-2 R-10
Perimeter Uninsulated concrete footing R-2 R-15
Windows Vinyl; double pane R-2.5 R-5
Doors
Man door Metal frame w/o thermal break R-2 R-5
Overhead Insulated metal panel rollup door R-10 R-10
Heating System
The building is heated by a hydronic heating system consisting of a fuel oil boiler and a hydronic
distribution system. The heating units consist of unit heaters in the maintenance bays and finned pipe
baseboards in the offices. A few areas are heated with electric heaters. The heating system has the
following pumps:
Pump P-1 circulates hydronic heating water to the majority of the building.
Pump P-2 circulates hydronic heating water to two unit heaters in the storage room under the
offices.
Douglas Parks and Recreation Shop 15 FINAL Energy Audit (October 2011)
Ventilation Systems
The following table summarizes the ventilation systems in the building.
Ventilation Systems
Area Fan System Description
Toilet Rooms - Ceiling exhaust fan in each room.
Domestic Hot Water System
An electric hot water heater supplies the fixtures. The aerators on the lavatories and the showerheads
are not water-conserving models.
Automatic Control System
The building has local controllers for the heating plant and heating units.
Lighting
Interior lighting consists of T12 fluorescent lighting with a few T8 fixtures. The lighting is manually
controlled except for an occupancy sensor in the Men’s Toilet.
Exterior lighting consists of high pressure sodium wall fixtures with integral photocell control.
Electric Equipment
The building has 6 computer workstations, 3 printers, and one copier that are left on continuously.
The break room has a non-Energy Star refrigerator.
The Men’s Toilet has a clothes dryer.
Douglas Parks and Recreation Shop 16 FINAL Energy Audit (October 2011)
Section 5
Methodology
Information for the energy audit was gathered through on-site observations, review of construction
documents, and interviews with operation and maintenance personnel. The EEMs are evaluated using
energy and life cycle cost analyses and are priority ranked for implementation.
Energy Efficiency Measures
Energy efficiency measures are identified by evaluating the building’s energy systems and comparing
them to systems in modern, high performance buildings. The process for identifying the EEMs
acknowledges the realities of an existing building that was 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 an existing building.
The EEMs represent practical measures to improve the energy efficiency of the buildings, taking into
account the realities of limited budgets. If a future major renovation project occurs, additional EEMs
common to high performance buildings should be incorporated.
Life Cycle Cost Analysis
The EEMs are evaluated using life cycle cost analysis which determines if an energy efficiency
investment will provide a savings over a 25-year life. The analysis incorporates construction,
replacement, maintenance, repair, and energy costs to determine the total cost over the life of the
EEM. 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 inflationary effects on operating
budgets. Accounting for energy inflation and the time value of money properly sums the true cost of
facility ownership and seeks to minimize the life cycle cost.
Construction Costs
The cost estimates are derived based on a preliminary understanding of the scope of each EEM as
gathered during the walk-through audit. The construction costs for in-house labor are $60/hour for
work typically performed by maintenance staff and $110.00 per hour for contract labor.
The cost estimate assumes the work will be performed as part of a larger renovation or energy
efficiency upgrade project. When implementing EEMs, the cost estimate should be revisited once the
scope and preferred method of performing the work has been determined. It is possible some EEMs
will not provide a life cycle savings when the scope is finalized.
Douglas Parks and Recreation Shop 17 FINAL Energy Audit (October 2011)
Maintenance Costs
Maintenance costs are based on in-house or contract labor using historical maintenance efforts and
industry standards. Maintenance costs over the 25-year life of each EEM are included in the life cycle
cost calculation spreadsheets and represent the level of effort to maintain the systems.
Energy Analysis
The energy performance of an EEM is evaluated within the operating parameters of the building. 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 EEM. This investment grade audit does not
utilize a computer model, so energy savings are calculated with factors that account for the dynamic
operation of the building. Energy savings and costs are estimated for the 25-year life of the EEM
using appropriate factors for energy inflation.
Prioritization
Each EEM is prioritized based on the life cycle savings to investment ratio (SIR) using the following
formula:
Prioritization Factor = Life Cycle Savings / Capital Costs
This approach factor puts significant weight on the capital cost of an EEM, making lower cost EEMs
more favorable.
Economic Factors
The following economic factors are significant to the findings.
Nominal Interest Rate: This is the nominal rate of return on an investment without regard to
inflation. The analysis uses a rate of 5%.
Inflation Rate: This is the average inflationary change in prices over time. The analysis uses an
inflation rate of 2%.
Economic Period: The analysis is based on a 25-year economic period with construction
beginning in 2010.
Fuel Oil
Fuel oil currently costs $3.20 (August 2011) per gallon for a seasonally adjusted blend of #1 and #2
fuel oil. The analysis is based on 6% fuel oil inflation which has been the average for the past 20-
years.
Electricity
Electricity is supplied by Alaska Electric Light & Power Company (AEL&P). The building is billed
for electricity under AEL&P’s Rate 21D, Small Government with Demand. This rate 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. AEL&P determines the electric
demand 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
electric charges, which include a recent 24% rate hike:
Douglas Parks and Recreation Shop 18 FINAL Energy Audit (October 2011)
AEL&P Small Government Rate with Demand
Charge 1 On-peak (Nov-May) Off-peak (June-Oct)
Energy Charge per kWh 6.43¢ 5.70¢
Demand Charge per kW $12.32 $8.24
Service Charge per month $27.16 $27.16
Over recent history, electricity inflation has been less than 1% per year, which has lagged general
inflation. An exception is the 24% rate hike that was primarily due to construction of additional
hydroelectric generation at Lake Dorothy. This project affords the community a surplus of power
which should bring electric inflation back to the historic rate of 1% per year. Load growth from
electric heat conversions is likely to increase generating and distribution costs, especially if diesel
supplementation is needed. Combining these two factors contribute to an assumed electricity inflation
rate of 3%.
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 5% Electricity Current rates
General Inflation Rate 2% Electricity Inflation 2%
Fuel Oil Cost (2012) $3.42/gal Fuel Oil Inflation 6%
Douglas Parks and Recreation Shop 19 FINAL Energy Audit (October 2011)
Appendix A
Energy and Life Cycle Cost Analysis
Douglas Parks and Recreation Shop 20 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
Basis
Economic
Study Period (years) 25 Nominal Discount Rate 5%General Inflation 3%
Energy
2011 $/gal Fuel Inflation 2012 $/gal
Fuel Oil $3.23 6% $3.42
Electricity $/kWh (2011)$/kW (2011)Inflation $/kWh (2012)$/kW (2012)
w/ Demand Charges $0.061 $10.62 2% $0.062 $10.83
w/o Demand Charges $0.102 -2% $0.102 -
EEM-8: Adjust Boiler Thermostat
Energy Analysis
Annual Gal % Savings Savings, Gal
7,500 -1.00% -75
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Adjust boiler thermostat 0 1 hr $60 $60
Energy Costs
Fuel Oil 1 - 25 -75 gal $3.42 ($7,278)
Net Present Worth ($7,200)
EEM-9: Change Electric Rate
Energy Analysis
Existing Proposed Savings
Effective $/kWh $0.129 $0.118 ($0.011)
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Change electric rate 0 1 hr $60 $60
Energy Costs
Electric Energy (Effective Cost) 1 - 25 37,800 kWh ($0.011) ($7,288)
Net Present Worth ($7,200)
EEM-10: Install Pipe Insulation
Energy Analysis
Service Size Length Bare BTUH Insul BTUH Factor kBtu η boiler Gallons
Heating 0.75 40 84 12 10% -2,523 68%-27
Heating 1.25 10 127 15 10% -981 68%-10
-37
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
3/4" pipe insulation 0 40 lnft $6 $240
1-1/2" pipe insulation 0 10 lnft $8 $80
Energy Costs
Fuel Oil 1 - 25 -37 gal $3.42 ($3,611)
Net Present Worth ($3,300)
Douglas Parks and Recreation Shop 21 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
EEM-11: Turn Off Computers
Energy Analysis
Equipment Number Watts Hours kWh
Workstation 6 -20 6,680 -802
Printers 3 -5 6,680 -100
Fax Machine 1 -5 6,680 -33
-935
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Employee instruction 0 1 hr $100 $100
Energy Costs
Electric Energy 1 - 25 -935 kWh $0.062 ($1,020)
Net Present Worth ($900)
EEM-12: Insulate Office Floor
Energy Analysis
Area,sqft R,exist R-new ΔT MBH Factor kBtu η boiler Gallons
420 1 22 10 -4 15% -5,268 68%-56
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install R-21 batt insulation 0 420 sqft $1.65 $693
Energy Costs
Fuel Oil 1 - 25 -56 gal $3.42 ($5,428)
Net Present Worth ($4,700)
EEM-13: Perform Boiler Combustion Test
Energy Analysis
Annual Gal % Savings Savings, Gal
7,500 -1.0% -75
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Purchase combustion analyzer 0 1 LS $700 $700
Annual Costs
Combustion test 1 - 25 2 hrs $60.00 $2,314
Energy Costs
Fuel Oil 1 - 25 -75 gal $3.42 ($7,278)
Net Present Worth ($4,300)
Douglas Parks and Recreation Shop 22 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
EEM-14: Replace Aerators
Energy Analysis
Fixture Existing Proposed Uses/day Days Water,Gals % HW kBTU kWh
Summer
Showerhead 20.0 10.0 0.1 90 -129 80% -69 -20
Sinks 0.3 0.2 30 90 -351 80% -187 -55
Lavatories 0.3 0.2 90 90 -1,458 80% -778 -228
Winter
Showerhead 20.0 10.0 0.1 198 -283 80% -151 -44
Sinks 0.3 0.2 5 198 -129 80% -69 -20
Lavatories 0.3 0.2 15 198 -535 80% -285 -84
-2,884 -451
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace lavatory aerators 0 4 ea $35 $140
Replace sink aerators 0 1 ea $35 $35
Replace showerhead 0 1 ea $35 $35
Energy Costs
Water 1 - 25 -3 kgals $10.960 ($554)
Electric Energy (Effective Cost)1 - 25 -451 kWh $0.102 ($810)
Net Present Worth ($1,200)
EEM-15: Install Valves on Unit Heaters
Energy Analysis
Loss, BTUH Number Factor Loss, kBTU Boiler Effic Fuel, gals
-1,500 4 15% -7,884 70% -83
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install automatic valves and connect to fan wiring 0 4 ea $500 $2,000
Energy Costs
Fuel Oil 1 - 25 -83 gal $3.42 ($8,096)
Net Present Worth ($6,100)
Gallons per Use
Douglas Parks and Recreation Shop 23 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
EEM-16: Install Boiler Room Heat Recovery
Energy Analysis
Heat Recovery
Boiler gph Jacket Loss MBH Hours Loss, kBtu Factor Recovery, kBtu η boiler Gallons
4 -1.5% -8 8,760 -72,796 50% -36,398 84%-313
Fan Energy
MBH ΔT CFM ΔP η, fan # Fans Hours kW kWh
8 25 308 1.50 35%2 7,500 0.3 2,321
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
300 CFM HRV 0 1 LS $4,000 $4,000
Ductwork 0 1 LS $3,000 $3,000
Electrical 0 1 LS $1,500 $1,500
Annual Costs
HRV maintenance 1 - 25 4 hrs $60.00 $4,628
Energy Costs
Electric Energy 1 - 25 2,321 kWh $0.062 $2,531
Electric Demand 1 - 25 3.7 kW $10.83 $705
Fuel Oil 1 - 25 -313 gal $3.42 ($30,362)
Net Present Worth ($14,000)
EEM-17: Interlock Heaters with Overhead Doors
Energy Analysis
# Heaters Open min/day Days/year MBH kBtu η boiler Gallons
4 60 296 -15 -17,760 68% -189
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install door limit switches and wire to heater controls 0 4 ea $2,000 $8,000
Energy Costs
Fuel Oil 1 - 25 -189 gal $3.42 ($18,300)
Net Present Worth ($10,300)
EEM-18: Install Instantaneous HW Heater
Energy Analysis
Length Gal/ft Loss/day Gal/yr kBtu η boiler Gallons
72 0.016 -5 -1,498 -999 68% -11
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install instantaneous hot water heater 0 1 LS $1,500 $1,500
Energy Costs
Water 1 - 25 -1 kgals $10.960 ($288)
Fuel Oil 1 - 25 -11 gal $3.42 ($1,030)
Net Present Worth $200
Douglas Parks and Recreation Shop 24 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
EEM-19: Install Water-conserving Fixtures
Energy Analysis
Fixture Existing Proposed Uses/day Days Water,Gals
Summer
Toilets 1.6 1.1 30 90 -1,350
Urinals 1.0 0.5 60 90 -2,700
Winter
Toilets 1.6 1.1 5 198 -495
Urinals 1.0 0.5 10 198 -990
-5,535
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace toilets 0 4 ea $800 $3,200
Replace Urinals 0 1 ea $1,100 $1,100
Energy Costs
Water 1 - 25 -6 kgals $10.960 ($1,063)
Net Present Worth $3,200
Gallons per Use
Douglas Parks and Recreation Shop 25 FINAL Energy Audit (October 2011)
Appendix B
Energy and Utility Data
Douglas Parks and Recreation Shop 26 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
ELECTRIC RATE
Electricity ($ / kWh )0.0611 0.0592
Demand ( $ / kW )14.30 9.11
Customer Charge ( $ / mo )99.24 99.24
Sales Tax ( % )0.0% 0.0%
ELECTRICAL CONSUMPTION AND DEMAND
kWh kW kWh kW kWh kW kWh kW
Jan 4,735 17 3,673 18 2,649 15 2,822 15 3,470
Feb 5,042 19 4,391 21 2,882 13 2,689 15 3,751
Mar 4,996 20 4,241 18 3,208 15 2,599 15 3,761
Apr 4,461 21 3,786 19 2,774 14 2,748 15 3,442
May 4,032 18 2,017 11 2,350 12 2,513 14 2,728
Jun 3,693 16 2,060 11 2,104 14 2,257 13 2,529
Jul 3,375 17 2,245 18 1,990 13 2,942 17 2,638
Aug 3,631 18 2,411 16 1,839 13 4,806 14 3,172
Sep 4,074 18 2,369 15 2,517 15 2,567 9 2,882
Oct 4,018 19 2,463 20 2,446 19 3,288 11 3,054
Nov 4,132 21 2,754 17 2,757 17 2,750 8 3,098
Dec 4,052 20 3,051 17 2,903 15 3,090 15 3,274
Total 50,241 35,461 30,419 35,071 37,798
Average 4,187 19 2,955 17 2,535 15 2,923 13 3,150
Load Factor 30.6%24.0%23.7%29.9%16
ELECTRIC BILLING DETAILS
Month Energy Demand Cust & Tax Total Energy Demand Cust & Tax Total % Change
Jan 162 221 99 482 172 209 99 481 -0.2%
Feb 176 193 99 468 164 215 99 478 2.1%
Mar 196 219 99 515 159 210 99 468 -9.1%
Apr 169 206 99 475 168 219 99 486 2.4%
May 144 178 99 421 154 205 99 458 8.8%
Jun 129 131 99 359 138 114 99 352 -2.0%
Jul 122 116 99 337 180 154 99 433 28.4%
Aug 112 115 99 327 294 128 99 521 59.5%
Sep 154 133 99 386 157 82 99 338 -12.5%
Oct 149 173 99 422 201 98 99 398 -5.7%
Nov 168 238 99 505 168 118 99 385 -23.8%
Dec 177 209 99 486 189 218 99 506 4.2%
Total $ 1,859 $ 2,133 $ 1,191 $ 5,183 $ 2,143 $ 1,971 $ 1,191 $ 5,304 2.3%
Average $ 155 $ 178 $ 99 $ 432 $ 179 $ 164 $ 99 $ 442 2.3%
Cost ($/kWh)$0.170 40% 37% 22% $0.151 -11.2%
Electrical costs are based on the current electric rates.
2009 2010
2010
AEL&P Electric Rate 24 On-Peak
Nov-May
Off-peak
Jun-Oct
Month 2007 2008 2009 Average
Douglas Parks and Recreation Shop 27 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Annual Electric Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
0
1,000
2,000
3,000
4,000
5,000
6,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Use (kWh)Month of the Year
Electric Use History
2007
2008
2009
2010
0
5
10
15
20
25
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Demand (kW)Month of the Year
Electric Demand History
2007
2008
2009
2010
Douglas Parks and Recreation Shop 28 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Electric Cost
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop 2010
$ 0
$ 100
$ 200
$ 300
$ 400
$ 500
$ 600
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Cost (USD)Month of the Year
Electric Cost Breakdown
2010 Electric Use (kWh) Costs
Electric Demand (kW) Costs
Customer Charge and Taxes
0
2
4
6
8
10
12
14
16
18
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 Electric Demand (kW)Electric Use (kWh)Month of the Year
Electric Use and Demand Comparison
2010
Electric Use
Electric Demand
Douglas Parks and Recreation Shop 29 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Annual Fuel Oil Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
Year Fuel Oil Degree Days
2,007 8,580 9,282
2,008 7,605 9,093
2,009 4,550 9,284
2,010 6,175 9,013
5,000
6,000
7,000
8,000
9,000
10,000
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
2007 2008 2009 2010 Degree DaysGallons of Fuel OilYear
Annual Fuel Oil Use
Fuel Oil
Degree Days
Douglas Parks and Recreation Shop 30 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC Annual Water Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Douglas Parks and Recreation Shop
Year Water
2,007 4,000
2,008 12,000
2,009 60,000
2,010 72,000
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
2007 2008 2009 2010Gallons of WaterYear
Annual Water Use
Douglas Parks and Recreation Shop 31 FINAL Energy Audit (October 2011)
Alaska Energy Engineering LLC
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Annual Energy Consumption and Cost
Energy Cost Area ECI EUI
Fuel Oil $3.42 6,720 $4.32 170
Electricity $0.093
Source Cost
Electricity 37,798 kWh $3,500 129 11%
Fuel Oil 7,453 Gallons $25,500 1,012 89%
Totals -$29,000 1,141 100%
Annual Energy Consumption and Cost
Consumption Energy, MMBtu
Douglas Parks and Recreation Shop 32 FINAL Energy Audit (October 2011)
Appendix C
Equipment Data
Douglas Parks and Recreation Shop 33 FINAL Energy Audit (October 2011)
MotorUnit IDLocation Function Make Model Capacity HP / Volts / RPM / Effic NotesParks Break Room RefrigeratorFrigidaire EliteBoiler Room BoilerCrown F5416 MBHBoiler Room BurnerMectron 15 M 4.0 GPHNozzle changed to 2.0 GPH.P-1 Boiler RoomLead CirculationGrundfos UMS 50-40 144-1980-260 WattsP-2 Boiler RoomStand-by CirculationGrundfos UPS 20-42 50-70-95 WattsOfficesComputer WorkstationsSix workstationsMen's Rest Room Domestic Hot Water RHEEM 82V52-2 50 Gallons4500 Watts / 240 VMajor Equipment Inventory - Douglas Parks and Recreation ShopDouglas Parks and Recreation Shop 34 FINAL Energy Audit (October 2011)
Appendix D
Abbreviations
AHU Air handling unit
BTU British thermal unit
BTUH BTU per hour
CBJ City and Borough of Juneau
CMU Concrete masonry unit
CO2 Carbon dioxide
CUH Cabinet unit heater
DDC Direct digital controls
DHW Domestic hot water
EAD Exhaust air damper
EEM Energy efficiency measure
EF Exhaust fan
Gyp Bd Gypsum board
HVAC Heating, Ventilating, Air-
conditioning
HW Hot water
HWRP Hot water recirculating pump
KVA Kilovolt-amps
kW Kilowatt
kWh Kilowatt-hour
LED Light emitting diode
MBH 1,000 Btu per hour
MMBH 1,000,000 Btu per hour
OAD Outside air damper
PSI Per square inch
PSIG Per square inch gage
RAD Return air damper
RF Return fan
SIR Savings to investment ratio
SF Supply fan
UV Unit ventilator
VAV Variable air volume
VFD Variable frequency drive
Douglas Parks and Recreation Shop 35 FINAL Energy Audit (October 2011)