HomeMy WebLinkAboutSNP Public Works 2012-EEENERGY AUDIT – FINAL REPORT
PUBLIC WORKS BUILDING
1031 Diamond Hill Road
Saint Paul, Alaska
Prepared for:
Ms. Wanda Melovidov
950 Girbash Street
Saint Paul, Alaska
Prepared by:
David Lanning PE, CEA
Jeremy Spargur EIT, CEAIT
July 16, 2012
Acknowledgment: “This material is based upon work supported by the Department of
Energy under Award Number DE-EE0000095”
Managing Office
2400 College Road 3105 Lakeshore Dr. Suite 106A 4402 Thane Road
Fairbanks, Alaska 99709 Anchorage, Alaska 99517 Juneau, Alaska 99801
p. 907.452.5688 p. 907.222.2445 p: 907.586.6813
f. 907.452.5694 f. 907.222.0915 f: 907.586.6819
www.nortechengr.com
ENVIRONMENTAL ENGINEERING, HEALTH & SAFETY
Anch: 3105 Lakeshore Dr. Ste 106A, 99517 907.222.2445 Fax: 222.0915
Fairbanks: 2400 College Road, 99709 907.452.5688 Fax: 452.5694
Juneau: 4402 Thane Road, 99801 907.586.6813 Fax: 586.6819
info@nortechengr.com www.nortechengr.com
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY .................................................................................................. 1
2.0 INTRODUCTION ............................................................................................................... 4
2.1 Building Use, Occupancy, Schedules and Description .......................................... 4
2.1.1 Building Use ................................................................................................. 4
2.1.2 Building Occupancy and Schedules ............................................................. 4
2.1.3 Building Description ...................................................................................... 4
2.2 BENCHMARKING ............................................................................................................ 7
2.2.1 Energy Utilization Index of 2010 ................................................................ 8
2.2.2 Cost Utilization Index of 2010 .................................................................... 9
2.2.3 Seasonal Energy Use Patterns ................................................................ 10
2.2.4 Future Energy Monitoring ........................................................................ 11
2.2.5 Future Energy Source Conversion ........................................................... 11
3.0 ENERGY CONSUMPTION AND MODELING RESULTS .............................................. 12
3.1 Understanding How AkWarm Models Energy Consumption ............................... 13
3.1.1 AkWarm Calculated Savings for the Public Works Building .................... 14
3.1.2 AkWarm Projected Energy Costs after Modifications .............................. 15
3.2 Energy Efficiency Measures Calculated Outside AkWarm .................................. 16
4.0 BUILDING OPERATION AND MAINTENANCE (O & M) .............................................. 17
4.1 Operations and Maintenance .............................................................................. 17
4.2 Building Specific Recommendations ................................................................... 17
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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APPENDICES
Appendix A Recommended Energy Efficiency Measures ........................................... 19
Appendix B Energy Efficiency Measures that are NOT Recommended ..................... 27
Appendix C Significant Equipment List ....................................................................... 29
Appendix D Local Utility Rate Structure ...................................................................... 31
Appendix E Analysis Methods .................................................................................... 32
Appendix F Audit Limitations ...................................................................................... 33
Appendix G References .............................................................................................. 34
Appendix H Typical Energy Use and Cost – Fairbanks and Anchorage ..................... 35
Appendix I Typical Energy Use and Cost – Continental U.S. .................................... 36
Appendix J List of Conversion Factors and Energy Units .......................................... 37
Appendix K List of Acronyms, Abbreviations, and Definitions .................................... 38
Appendix L Building Floor Plan .................................................................................. 39
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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1.0 EXECUTIVE SUMMARY
NORTECH has completed an ASHRAE Level II Energy Audit of the Public Works Building, a
9,725 square foot facility. The audit began with benchmarking which resulted in a calculation of
the energy consumption per square foot. A site inspection was completed on September 9,
2011 to obtain information about the lighting, heating, ventilation, cooling and other building
energy uses. The existing usage data and current systems were then used to develop a
building energy consumption model using AkWarm.
Once the model was calibrated, a number of Energy Efficiency Measures (EEMs) were
developed from review of the data and observations. EEMs were evaluated and ranked on the
basis of both energy savings and cost using a Savings/Investment Ratio (SIR). While these
modeling techniques were successful in verifying that many of the EEMs would save energy,
not all of the identified EEMs were considered cost effective based on the hardware, installation,
and energy costs at the time of this audit.
While the need for a major retrofit can typically be identified by an energy audit, upgrading
specific systems often requires collecting additional data and engineering and design efforts that
are beyond the scope of the Level II energy audit. The necessity and amount of design effort
and cost will vary depending on the scope of the specific EEMs planned and the sophistication
and capability of the entire design team, including the building owners and operators. During
the budgeting process for any major retrofit identified in this report, the building owner should
add administrative and supplemental design costs to cover the individual needs of their own
organization and the overall retrofit project.
The following table, from AkWarm, is a summary of the recommended EEMs for the Public
Works Building. Additional discussion of the modeling process can be found in Section 3.
Details of each individual EEM can be found in Appendix A of this report. A summary of EEMs
that were evaluated but are not currently recommended is located in Appendix B.
The costs for heating the building presented in this report represents the estimated cost to heat
the building with boilers using #2 heating fuel. The purpose is to allow determination of useful
ways to reduce heating energy. Therefore, the savings listed in EEMs 3, 5, 7, 11, and 25 below
can only be realized if the building is no longer heated with a free source.
PRIORITY LIST – ENERGY EFFICIENCY MEASURES
Rank
Feature
Improvement Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio (SIR)
Simple
Payback
(Years)
1
Other Electrical:
Dayton Space
Heater
Improve Manual Switching $276 $1 1,700 0.0
2 Other Electrical:
Optimus Heater Improve Manual Switching $220 $1 1,400 0.0
Energy Audit – Final Report
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PRIORITY LIST – ENERGY EFFICIENCY MEASURES
Rank
Feature
Improvement Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio (SIR)
Simple
Payback
(Years)
3
Setback
Thermostat:
Zone 1 (Main
Shop)
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Zone 1 (Main Shop) space.
$2,328 $1,500 21 0.6
4 Other Electrical:
Ceiling Fans Improve Manual Switching $286 $100 18 0.4
5
Setback
Thermostat:
Mezzanine
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Mezzanine space.
$1,903 $1,500 17 0.8
6 Lighting: Main
Shop
Replace with 9 100 W CFL
spirals $2,354 $900 16 0.4
7
Setback
Thermostat:
Zone 2 (Offices)
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Zone 2 (Offices) space.
$870 $1,500 7.8 1.7
8 Lighting: Outdoor Replace with 3 LED 4W
Module StdElectronic $842 $700 7.7 0.8
9 Lighting: Outdoor
Replace with LED 4W Module
StdElectronic and Controls
retrofit
$180 $200 5.8 1.1
10 Lighting: Outdoor Replace with 2 LED Wall Pack $1,429 $1,714 5.3 1.2
11
Garage Door:
Main Shop-
Garage Door
Add R-5 insulating blanket to
garage door $220 $587 5.1 2.7
12 Lighting: Dmitri
Office
Replace with LED (2) 17W
Module StdElectronic $72 $175 3.5 2.4
13 Lighting: Main
Shop
Replace with FLUOR (2) T8 4'
F32T8 32W Standard Instant
HighLight HighEfficElectronic
$23 $49 2.9 2.2
14 HVAC And DHW Use district hot water to supply
heat for DHW $388 $2,000 2.6 5.2
15 Lighting: Dmitri
Storage
Replace with 2 LED (2) 17W
Module StdElectronic $81 $350 2.0 4.3
16 Lighting:
Stairwell, West
Replace with 2 LED (2) 17W
Module StdElectronic $73 $350 1.8 4.8
17 Lighting: Front
Desk
Replace with 16 LED (2) 17W
Module StdElectronic $581 $2,800 1.8 4.8
18
Lighting:
Conference
Room
Replace with 6 LED (2) 17W
Module StdElectronic $163 $810 1.7 5.0
19 Lighting: Dmitri
Office
Replace with 2 LED (2) 17W
Module StdElectronic $61 $350 1.5 5.7
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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PRIORITY LIST – ENERGY EFFICIENCY MEASURES
Rank
Feature
Improvement Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio (SIR)
Simple
Payback
(Years)
20 Lighting: Office-
Mezzanine
Replace with 2 LED (2) 17W
Module StdElectronic $54 $350 1.3 6.5
21
Lighting:
Womens
Restroom
Remove Manual Switching and
Add new Occupancy Sensor $31 $150 1.3 4.8
22 Lighting: Mens
Restroom
Replace with 2 LED (2) 17W
Module StdElectronic $72 $350 1.3 4.9
23 Lighting: Hallway Replace with 2 LED (2) 17W
Module StdElectronic $72 $350 1.3 4.9
24 Lighting: Hallway
2
Replace with 2 LED (2) 17W
Module StdElectronic $72 $350 1.3 4.9
25
On- or Below-
Grade Floor,
Perimeter: 6"
Reinf. Concrete
Install 2' of R-10 rigid board
insulation around perimeter of
Slab (vertical or horizontal).
$228 $4,332 1.2 19
26 Lighting: Freds
Office
Replace with 6 LED (2) 17W
Module StdElectronic $143 $1,050 1.2 7.3
27 Lighting: City
Admin Office
Replace with 6 LED (2) 17W
Module StdElectronic $143 $1,050 1.2 7.3
TOTAL, cost-effective measures $13,165 $23,569 5.6 1.8
It is also recommended that a BTU meter be installed at the heat exchanger to monitor space
heating usage.
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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2.0 INTRODUCTION
NORTECH contracted with the Alaska Housing Finance Corporation to perform an ASHRAE
Level II Energy Audits for publically owned buildings in Alaska. This report presents the findings
of the utility benchmarking, modeling analysis, the recommended building modifications, and
building use changes that are expected to save energy and money.
The report is organized into sections covering:
description of the facility,
the building’s historic energy usage (benchmarking),
estimating energy use through energy use modeling,
evaluation of potential energy efficiency or efficiency improvements, and
recommendations for energy efficiency with estimates of the costs and savings.
2.1 Building Use, Occupancy, Schedules and Description
2.1.1 Building Use
The Public Works building is primarily used as a city office and warehouse for city materials.
The west side of the building has two levels of office space including a conference room on the
second floor. A portion of the warehouse is used for storage while the other portion is used as a
fully-equipped, wood shop.
2.1.2 Building Occupancy and Schedules
The building is occupied during a standard work week from Monday through Friday from 8 am to
5 pm by approximately 10 people.
2.1.3 Building Description
The Public Works Building is a steel-framed, metal building with 8” purlins and plastic wrapped
fiberglass batt insulation sitting on an un-insulated, on grade, concrete slab. Three man doors
and 2 garage doors allow access into the building for vehicles and workers. Windows are
located in rooms on the west, north, and east walls where the office and storage spaces are.
Building Envelope
Building Envelope: Walls
Wall Type Description Insulation Notes
Above Grade Walls 8” Metal purlins R-19 fiberglass batt. No signs of insulation
damage.
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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Heating and Ventilation Systems
A Heat Exchanger transfers heat from district hot water lines to circulation loops. Three zones
circulate glycol through the building providing heat to the baseboards in the office, floor coils in
the shop and heating coils in the air handler. Each circulation pump is controlled with a manual
switch and remains on constantly. The air handler is designed to ventilate the entire building,
but the office supply duct has been blocked due to the amount of dust that circulates through
the building. The building is equipped with a direct digital control (DDC) system which operates
the heating and ventilation equipment but is not operating correctly and currently, inadequate
fresh air is provided.
Cooling System
The Public Works Building is not equipped with a cooling system; however, some economizer
cooling seems possible using the ventilation system.
Building Envelope: Floors
Floor Type Description Insulation Notes
On Grade Floor Un-insulated concrete slab None None
Building Envelope: Roof
Roof Type Description Insulation Notes
All Roofs 8” metal purlin hot roof R-13 fiberglass batt No signs of insulation
damage.
Building Envelope: Doors and Windows
Door and Window Type Description Estimated
R-value Notes
2-Garage Doors 2” sectional doors 3.2 None
3-Exterior Doors Insulated metal doors 2.5 Corrosion at edges due
to weather
Fiberglass Windows Double Pane 2.2 None
Energy Audit – Final Report
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Energy Management
The public works building is equipped with a Barber-Colman Network 8000 Direct Digital Control
(DDC) system. This system is designed to automate the controls and allow remote monitoring.
In the Public Works Building there are several unknown mechanical problems which limit the
effectiveness of the Network 8000 system. Repairs should be made to this system, so that heat
can be controlled and the building can be more comfortable.
Lighting Systems
The majority of the lights in the Public Works building are ceiling mounted fixtures with 32 watt,
T8 bulbs (1” diameter, 4’ long). The shop is equipped with nine 400 watt metal halide fixtures.
The exterior of the building is lit with 100 and 250 watt metal halide bulbs in wall mounted
fixtures.
Domestic Hot Water
Domestic hot water is provided in an electric water heater.
Energy Audit – Final Report
Public Works Building
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2.2 BENCHMARKING
Benchmarking building energy use consists of obtaining and then analyzing two years of energy
bills. The original utility bills are necessary to determine the raw usage and charges as well as
to evaluate the utility’s rate structure. The metered usage of electrical and natural gas
consumption is measured monthly, but heating oil, propane, wood, and other energy sources
are normally billed upon delivery and provide similar information. During benchmarking,
information is compiled in a way that standardizes the units of energy and creates energy use
and billing rate information statistics for the building on a square foot basis. The objectives of
benchmarking are:
to understand patterns of use,
to understand building operational characteristics,
for comparison with other similar facilities in Alaska and across the country, and
to offer insight in to potential energy savings.
The results of the benchmarking, including the energy use statistics and comparisons to other
areas, are discussed in the following sections.
The Public Works Building receives unmetered waste heat from the electric company so no
records are available to evaluate usage history. Occupancy and equipment schedules and
temperature set points were obtained in order to model energy usage. This information was
input into the AkWarm program and energy savings was estimated without calibration.
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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2.2.1 Energy Utilization Index of 2010
The primary benchmarking statistic is the Energy Use Index (EUI). The EUI is calculated from
the utility bills and provides a simple snapshot of the quantity of energy actually used by the
building on a square foot and annual basis. The calculation converts the total energy use for
the year from all sources in the building, such as heating fuel and electrical usage, into British
Thermal Units (BTUs). This total usage is then divided by the number of square feet of the
building. The EUI units are BTUs per square foot per year.
The BTUs, estimated from the obtained schedule, to heat the Public Works Building were added
to the metered electric data to get an estimate of the total energy usage.
The benchmark analysis found that the Public Works Building has an estimated EUI of 70,000
BTUs per square foot per year.
The EUI is useful in comparing this building’s energy use to that of other similar buildings in
Alaska and in the Continental United States. The EUI can be compared to average energy use
in 2003 found in a study by the U.S. Energy Information Administration of commercial buildings
(abbreviated CBECS, 2006). That report found an overall average energy use of about 90,000
BTUs per square foot per year while studying about 6,000 commercial buildings of all sizes,
types, and uses that were located all over the Continental U.S. (see Table C3 in Appendix I).
In a recent and unpublished state-wide benchmarking study sponsored by the Alaska Housing
Finance Corporation, schools in Fairbanks averaged 62,000 BTUs per square foot and schools
in Anchorage averaged 123,000 BTUs per square foot annual energy use. The chart below
shows the Public Works Building relative to these values. These findings are discussed further
in Appendix H.
70,000 62,000
123,000
0
20000
40000
60000
80000
100000
120000
140000
Btu/ Sq. FtAnnual Energy Utilization Index (Total Energy/ SF)
Public Works Fairbanks Anchorage
Energy Audit – Final Report
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2.2.2 Cost Utilization Index of 2010
Another benchmarking statistic that is useful is the Cost Utilization Index (CUI), which is the cost
for energy used in the building on a square foot basis per year. The CUI is calculated from the
cost for utilities for a year period. The CUI permits comparison of buildings on total energy cost
even though they may be located in areas with differing energy costs and differing heating
and/or cooling climates. The cost of energy, including heating oil, natural gas, and electricity,
can vary greatly over time and geographic location and can be higher in Alaska than other parts
of the country.
The utility company that provides the waste heat to the machine shop and other city buildings is
owned by the city and the heat is provided at no charge. In order to create a meaningful CUI
the waste heat cost was equated to the local price of #2 heating oil, on the basis of energy
content. This represents the operational cost if boilers were used to heat the building.
The CUI for Public Works Building is about $5.02. This is based on utility costs from 2010 and
the following rates:
Electricity at $0.54 / kWh ($15.82 / Therm)
# 2 Fuel Oil at $4.95 / gallon ($3.54 / Therm)
The Department of Energy Administration study, mentioned in the previous section (CBECS,
2006) found an average cost of $2.52 per square foot in 2003 for 4,400 buildings in the
Continental U.S (Tables C4 and C13 of CBDES, 2006). Schools in Fairbanks have an average
cost for energy of $2.42 per square foot while Anchorage schools average $2.11 per square
foot. The chart below shows the Public Works Building relative to these values. More details
are included in Appendix H.
$5.02
$2.42
$2.11
$0.00
$1.00
$2.00
$3.00
$4.00
$5.00
$6.00
Annual Energy Cost Index (Total Cost/SF)
Public Works Fairbanks Anchorage
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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2.2.3 Seasonal Energy Use Patterns
Energy consumption is often highly correlated with seasonal climate and usage variations. The
graphs below show the electric and district heat consumption of this building over the course of
two years. The lowest monthly use is called the baseline use. The electric baseline often
reflects year round lighting consumption. The District Heat Consumption graph is based on
results of the AkWarm model.
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
Jan-09Mar-09May-09Jul-09Sep-09Nov-09Jan-10Mar-10May-10Jul-10Sep-10Nov-10KWHElectrical Consumption
0
10
20
30
40
50
60
70
80
Jan-09Mar-09May-09Jul-09Sep-09Nov-09Jan-10Mar-10May-10Jul-10Sep-10Nov-10mmBtuEstimated District Heat Consumption
Energy Audit – Final Report
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2.2.4 Future Energy Monitoring
Energy accounting is the process of tracking energy consumption and costs. It is important for
the building owner or manager to monitor and record both the energy usage and cost each
month. Comparing trends over time can assist in pinpointing major sources of energy usage and
aid in finding effective energy efficiency measures. There are two basic methods of energy
accounting: manual and automatic. Manual tracking of energy usage may already be performed
by an administrative assistant: however if the records are not scrutinized for energy use, then
the data is merely a financial accounting. Digital energy tracking systems can be installed. They
display and record real-time energy usage and accumulated energy use and cost. There are
several types which have all of the information accessible via Ethernet browser.
2.2.5 Future Energy Source Conversion
It is understood that TDX, a regional electric utility, is converting a considerable amount of
electric generation in the Aleutian region to wind power. The current use of waste heat
generated from the electric generators is a very efficient use of a waste energy stream, however
if the total electric use of St. Paul drops considerably, the amount of available waste heat would
also drop. Therefore, it should be noted that the addition of large electric water heaters to the
main glycol loop could be used to add short term, excess power from the wind generators to the
heating system in this building.
Energy Audit – Final Report
Public Works Building
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3.0 ENERGY CONSUMPTION AND MODELING RESULTS
After benchmarking of a building is complete and the site visit has identified the specific systems
in the building, a number of different methods are available for quantifying the overall energy
consumption and to model the energy use. These range from relatively simple spreadsheets to
commercially available modeling software capable of handling complex building systems.
NORTECH has used several of these programs and uses the worksheets and software that
best matches the complexity of the building and specific energy use that is being evaluated.
Modeling of an energy efficiency measure (EEM) requires an estimate of the current energy
used by the specific feature, the estimated energy use of the proposed EEM and its installed
cost. EEMs can range from a single simple upgrade, such as light bulb type or type of motor, to
reprogramming of the controls on more complex systems. While the need for a major retrofit
can typically be identified by an energy audit, the specific system upgrades often require
collecting additional data and engineering and design efforts that are beyond the scope of the
Level II energy audit.
Based on the field inspection results and discussions with the building owners/operators,
auditors developed potential EEMs for the facility. Common EEMs that could apply to almost
every older building include:
Reduce the envelope heat losses through:
o increased building insulation, and
o better windows and doors
Reduce temperature difference between inside and outside using setback thermostats
Upgrade inefficient:
o lights,
o motors,
o refrigeration units, and
o other appliances
Reduce running time of lights/appliances through:
o motion sensors,
o on/off timers,
o light sensors, and
o other automatic/programmable systems
The objective of the following sections is to describe how the overall energy use of the building
was modeled and the potential for energy savings. The specific EEMs that provide these overall
energy savings are detailed in Appendix A of this report. While the energy savings of an EEM is
unlikely to change significantly over time, the cost savings of an EEM is highly dependent on the
current energy price and can vary significantly over time. An EEM that is not currently
recommended based on price may be more attractive at a later date or with higher energy
prices.
Energy Audit – Final Report
Public Works Building
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3.1 Understanding How AkWarm Models Energy Consumption
NORTECH used the AkWarm model for evaluating the overall energy consumption at Public
Works Building. The AkWarm program was developed by the Alaska Housing Finance
Corporation (AHFC) to model residential energy use. The original AkWarm is the modeling
engine behind the successful residential energy upgrade program that AHFC has operated for a
number of years. In the past few years, AHFC has developed a version of this model for
commercial buildings.
Energy use in buildings is modeled by calculating energy losses and consumption, such as:
• Heat lost through the building envelope components, including windows, doors,
walls, ceilings, crawlspaces, and foundations. These heat losses are computed for
each component based on the area, heat resistance (R-value), and the difference
between the inside temperature and the outside temperature. AkWarm has a library
of temperature profiles for villages and cities in Alaska.
• Window orientation, such as the fact that south facing windows can add heat in the
winter but north-facing windows do not.
• Inefficiencies of the heating system, including the imperfect conversion of fuel oil or
natural gas due to heat loss in exhaust gases, incomplete combustion, excess air,
etc. Some electricity is also consumed in moving the heat around a building through
pumping.
• Inefficiencies of the cooling system, if one exists, due to various imperfections in a
mechanical system and the required energy to move the heat around.
• Lighting requirements and inefficiencies in the conversion of electricity to light;
ultimately all of the power used for lighting is converted to heat. While the heat may
be useful in the winter, it often isn’t useful in the summer when cooling may be
required to remove the excess heat. Lights are modeled by wattage and operational
hours.
• Use and inefficiencies in refrigeration, compressor cooling, and heat pumps. Some
units are more efficient than others. Electricity is required to move the heat from
inside a compartment to outside it. Again, this is a function of the R-Value and the
temperature difference between the inside and outside of the unit.
• Plug loads such as computers, printers, mini-fridges, microwaves, portable heaters,
monitors, etc. These can be a significant part of the overall electricity consumption
of the building, as well as contributing to heat production.
• The schedule of operation for lights, plug loads, motors, etc. is a critical component
of how much energy is used.
AkWarm adds up these heat losses and the internal heat gains based on individual unit usage
schedules. These estimated heat and electrical usages are compared to actual use on both a
yearly and seasonal basis. If the AkWarm model is within 5 % to 10% of the most recent 12
months usage identified during benchmarking, the model is considered accurate enough to
make predictions of energy savings for possible EEMs..
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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3.1.1 AkWarm Calculated Savings for the Public Works Building
Based on the field inspection results and discussions with the building owners/operators,
auditors developed potential EEMs for the facility. These EEMs are then entered into AkWarm
to determine if the EEM saves energy and is cost effective (i.e. will pay for itself). AkWarm
calculates the energy and money saved by each EEM and calculates the length of time for the
savings in reduced energy consumption to pay for the installation of the EEM. AkWarm makes
recommendations based the Savings/Investment Ratio (SIR), which is defined as ratio of the
savings generated over the life of the EEM divided by the installed cost. Higher SIR values are
better and any SIR above one is considered acceptable. If the SIR of an EEM is below one, the
energy savings will not pay for the cost of the EEM and the EEM is not recommended.
Preferred EEMs are listed by AkWarm in order of the highest SIR.
A summary of the savings from the recommended EEMs are listed in this table.
Description Space Heating Water
Heating Lighting Refrigeration Other
Electrical
Ventilation
Fans Total
Existing
Building $26,041 $2,197 $12,494 $1,643 $5,896 $498 $48,769
With All
Proposed
Retrofits
$23,170 $735 $4,739 $1,643 $4,819 $498 $35,604
Savings $2,871 $1,462 $7,755 $0 $1,077 $0 $13,165
Space heating energy can be saved by the itemized EEMs but no real money can be saved
unless the waste heat energy is no longer provided free.
Energy Audit – Final Report
Public Works Building
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3.1.2 AkWarm Projected Energy Costs after Modifications
The AkWarm recommended EEMs appear to result in significant savings in space heating,
lighting and water heating. The energy cost by end use breakdown was provided by AkWarm
based on the field inspection and does not indicate that all individual fixtures and appliances
were direct measured. The current energy costs are shown below on the left hand bar of the
graph and the projected energy costs, assuming use of the recommended EEMs, are shown on
the right.
This graphical format allows easy visual comparison of the various energy requirements of the
facility. In the event that not all recommended retrofits are desired, the proposal energy savings
can be estimated from visual interpretation from this graph.
$0
$10,000
$20,000
$30,000
$40,000
$50,000
Existing Retrofit
Ventilation and Fans
Space Heating
Refrigeration
Other Electrical
Lighting
Domestic Hot Water
Annual Energy Costs by End Use
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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3.2 Energy Efficiency Measures Calculated Outside AkWarm
The AkWarm program effectively models wood-framed and other buildings with standard
heating systems and relatively simple HVAC systems. AkWarm models of more complicated
mechanical systems are sometimes poor due to a number of simplifying assumptions and
limited input of some variables. Furthermore, AKWarm is unable to model complex HVAC
systems such as variable frequency motors, variable air volume (VAV) systems, those with
significant digital or pneumatic controls or significant heat recovery capacity. In addition, some
other building methods and occupancies are outside AkWarm capabilities.
This report section is included in order to identify benefits from modifications to those more
complex systems or changes in occupant behavior that cannot be addressed in AkWarm.
The Public Works Building could be modeled well in AKWarm. Retrofits for the HVAC system
were adequately modeled in AKWarm and did not require additional calculations.
Energy Audit – Final Report
Public Works Building
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4.0 BUILDING OPERATION AND MAINTENANCE (O & M)
4.1 Operations and Maintenance
A well-implemented operation and maintenance (O & M) plan is often the driving force behind
energy savings. Such a plan includes preserving institutional knowledge, directing preventative
maintenance, and scheduling regular inspections of each piece of HVAC equipment within the
building. Routine maintenance includes the timely replacement of filters, belts and pulleys, the
proper greasing of bearings and other details such as topping off the glycol tanks. Additional
benefits to a maintenance plan are decreased down time for malfunctioning equipment, early
indications of problems, prevention of exacerbated maintenance issues, and early detection of
overloading/overheating issues. A good maintenance person knows the building’s equipment
well enough to spot and repair minor malfunctions before they become major retrofits.
Commissioning of a building is the verification that the HVAC systems act within the design or
usage ranges. This process ideally, though seldom, occurs as the last phase in construction.
HVAC system operation parameters degrade from ideal over time due to incorrect maintenance,
improper replacement pumps, changes in facility tenants or usage, changes in schedules, and
changes in energy costs or loads. Ideally, re-commissioning of a building should occur every
five to ten years. This ensures that the HVAC system meets the potentially variable use with
the most efficient means.
4.2 Building Specific Recommendations
The Public Works Building has several issues pertaining to basic operation and maintenance
that need to be addressed, including indoor air quality (IAQ) issues such as these:
Vehicles should not be stored inside because of the air handling system distributes
common air building wide.
Poor housekeeping has resulted in the accumulation of a significant amount of dust.
Scheduled deep cleaning in the spring and fall should alleviate this problem and prevent
future air quality problems.
The AHU room should be sealed from the rest of the building to help segregate dust
from the shop from the return air intake of the AHU.
In a dusty environment the air ducts should be cleaned regularly to prevent air quality
problems from developing.
And mechanical problems:
The AHU louvers do not operate automatically and the connecting rod to the outdoor air
and return air louvers is disengaged. These parts should be fixed and inspected
regularly to maintain optimum performance of the ventilation system.
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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APPENDICES
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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Appendix A Recommended Energy Efficiency Measures
A number of Energy Efficiency Measures (EEMs) are available to reduce the energy use and
overall operating cost for the facility. The EEMs listed below are those recommended by
AkWarm based on the calculated savings/investment ration (SIR) as described in Appendix E.
AkWarm also provides a breakeven cost, which is the maximum initial cost of the EEM that will
still return a SIR of one or greater.
This section describes each recommended EEM and identifies the potential energy savings and
installation costs. This also details the calculation of breakeven costs, simple payback, and the
SIR for each recommendation. The recommended EEMs are grouped together generally by the
overall end use that will be impacted.
A.1 Temperature Control
Setback temperatures should be programmed in the DDC system for the shop, downstairs
offices, and mezzanine office. Automatic temperature setbacks, based on occupancy
schedules reduce temperatures reliably. The heating loops in the slab in the shop and tool
room and the baseboards in the office are not adequately controlled by the DDC system and
tend to overheat the shop and under heat the office. Programming and repairing sensors or
controllers for the DDC system should bring the building back into control. Costs for this are
estimated to be $4500 which is spread out over three EEM’s to estimate savings.
Rank Building Space Recommendation
3 Zone 1 (Main Shop)
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Zone 1 (Main Shop) space.
Installation Cost $1,500 Estimated Life of Measure (yr.) 15 Energy Savings (/yr.) $2,328
Breakeven Cost $31,368 Savings-to-Investment Ratio 21 Simple Payback (yr.) 1
Rank Building Space Recommendation
5 Mezzanine
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Mezzanine space.
Installation Cost $1,500 Estimated Life of Measure (yr.) 15 Energy Savings (/yr.) $1,903
Breakeven Cost $25,644 Savings-to-Investment Ratio 17 Simple Payback (yr.) 1
Rank Building Space Recommendation
7 Zone 2 (Offices)
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Zone 2 (Offices) space.
Installation Cost $1,500 Estimated Life of Measure (yr.) 15 Energy Savings (/yr.) $870
Breakeven Cost $11,720 Savings-to-Investment Ratio 7.8 Simple Payback (yr.) 2
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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A.2 Electrical Loads
A.2.1 Lighting
The electricity used by lighting eventually ends up as heat in the building. In areas where
electricity is more expensive than other forms of energy, or in areas where the summer
temperatures require cooling; this additional heat can be both wasteful and costly. Converting
to more efficient lighting reduces cooling loads in the summer and allows the user to control
heat input in the winter. The conversion from T12 (one and a half inch fluorescent bulbs) to T8
(one inch), T5 (5/8 inch), Compact Fluorescent Lights (CFL), or LED bulbs provides a significant
increase in efficiency. LED bulbs can be directly placed in existing fixtures. The LED bulb
bypasses the ballast altogether, which removes the often irritating, “buzzing” noise that
magnetic ballasts tend to make.
It is economical to convert the fluorescent office lights to 17-watt LED bulbs because St. Paul
has high electric prices, and the district heat is free. These lights have high capital costs, but
consume approximately half the wattage of the current T8 bulbs. Four watt LED modules are a
good replacement for lights that are on for long period of time that do not require high levels of
illumination, such as building perimeter lighting.
Rank Location Existing Condition Recommendation
6 Main Shop 9 MH 400 Watt Magnetic with Manual
Switching Replace with 9 100 W CFL spirals
Installation Cost $900 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $2,354
Breakeven Cost $14,775 Savings-to-Investment Ratio 16 Simple Payback (yr.) 0
Rank Location Existing Condition Recommendation
8 Outdoor 3 MH 100 Watt StdElectronic with Manual
Switching
Replace with 3 LED 4W Module
StdElectronic
Installation Cost $700 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $842
Breakeven Cost $5,379 Savings-to-Investment Ratio 7.7 Simple Payback (yr.) 1
Rank Location Existing Condition Recommendation
9 Outdoor INCAN A Lamp, Halogen 75W with Manual
Switching
Replace with LED 4W Module
StdElectronic and Controls
retrofit
Installation Cost $200 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $180
Breakeven Cost $1,152 Savings-to-Investment Ratio 5.8 Simple Payback (yr.) 1
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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Rank Location Existing Condition Recommendation
10 Outdoor 2 MH 250 Watt StdElectronic with Manual
Switching Replace with 2 LED Wall Pack
Installation Cost $1,714 Estimated Life of Measure (yr.) 7 Energy Savings
(/yr.) $1,429
Breakeven Cost $9,128 Savings-to-Investment Ratio 5.3 Simple Payback (yr.) 1
Rank Location Existing Condition Recommendation
12 Dmitri Office
FLUOR (4) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with LED (2) 17W
Module StdElectronic
Installation Cost $175 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $72
Breakeven Cost $613 Savings-to-Investment Ratio 3.5 Simple Payback (yr.) 2
Rank Location Existing Condition Recommendation
13 Main Shop FLUOR (2) T12 4' F40T12 40W Standard
Magnetic with Manual Switching
Replace with FLUOR (2) T8 4'
F32T8 32W Standard Instant
HighLight HighEfficElectronic
Installation Cost $49 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $23
Breakeven Cost $143 Savings-to-Investment Ratio 2.9 Simple Payback (yr.) 2
Rank Location Existing Condition Recommendation
15 Dmitri Storage
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $81
Breakeven Cost $709 Savings-to-Investment Ratio 2.0 Simple Payback (yr.) 4
Rank Location Existing Condition Recommendation
16 Stairwell, West
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $73
Breakeven Cost $621 Savings-to-Investment Ratio 1.8 Simple Payback (yr.) 5
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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Rank Location Existing Condition Recommendation
17 Front Desk
16 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 16 LED (2) 17W
Module StdElectronic
Installation Cost $2,800 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $581
Breakeven Cost $4,942 Savings-to-Investment Ratio 1.8 Simple Payback (yr.) 5
Rank Location Existing Condition Recommendation
18 Conference Room
6 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching, Clock Timer or Other
Scheduling Control
Replace with 6 LED (2) 17W
Module StdElectronic
Installation Cost $810 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $163
Breakeven Cost $1,382 Savings-to-Investment Ratio 1.7 Simple Payback (yr.) 5
Rank Location Existing Condition Recommendation
19 Dmitri Office
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $61
Breakeven Cost $532 Savings-to-Investment Ratio 1.5 Simple Payback (yr.) 6
Rank Location Existing Condition Recommendation
20 Office-Mezzanine
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching, Clock Timer or Other
Scheduling Control
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $54
Breakeven Cost $460 Savings-to-Investment Ratio 1.3 Simple Payback (yr.) 6
Rank Location Existing Condition Recommendation
21 Women’s Restroom
FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Remove Manual Switching and
Add new Occupancy Sensor
Installation Cost $150 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $31
Breakeven Cost $197 Savings-to-Investment Ratio 1.3 Simple Payback (yr.) 5
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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Rank Location Existing Condition Recommendation
22 Mens Restroom
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $72
Breakeven Cost $451 Savings-to-Investment Ratio 1.3 Simple Payback (yr.) 5
Rank Location Existing Condition Recommendation
23 Hallway
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $72
Breakeven Cost $451 Savings-to-Investment Ratio 1.3 Simple Payback (yr.) 5
Rank Location Existing Condition Recommendation
24 Hallway 2
2 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $72
Breakeven Cost $450 Savings-to-Investment Ratio 1.3 Simple Payback (yr.) 5
Rank Location Existing Condition Recommendation
26 Freds Office
6 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 6 LED (2) 17W
Module StdElectronic
Installation Cost $1,050 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $141
Breakeven Cost $1,199 Savings-to-Investment Ratio 1.1 Simple Payback (yr.) 7
Rank Location Existing Condition Recommendation
27 City Admin Office
6 FLUOR (2) T8 4' F32T8 32W Standard
Instant HighLight HighEfficElectronic with
Manual Switching
Replace with 6 LED (2) 17W
Module StdElectronic
Installation Cost $1,050 Estimated Life of Measure (yr.) 10 Energy Savings (/yr.) $143
Breakeven Cost $1,215 Savings-to-Investment Ratio 1.2 Simple Payback (yr.) 7
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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A.2.2 Other Electrical Loads
There are a few electrical loads in the Public Works building that can be reduced by simple
administrative controls. Ceiling fans in the shop area were reported to be on at all time. The fans
can be set on a timer so that they turn off in the evenings when the last person leaves the shop
and turned back on when the first person arrives in the morning. The space heater usage will be
decrease when the heating controls are repaired so that the temperature can be maintained at a
comfortable level.
A.3 Building Envelope: Recommendations for change
A.3.1 Exterior Walls
There are no recommended EEM’s in this category. Adding insulation to the exterior walls is not
economical at this time.
Rank Location Existing Condition Recommendation
1 Dayton Space
Heater Space Heater with Manual Switching Repair heating system so heater
use is eliminated
Installation Cost $1 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $276
Breakeven Cost $1,724 Savings-to-Investment Ratio 1,700 Simple Payback (yr.) 0
Auditors Notes: keep thermostat at a reasonable temperature to avoid having to use space heaters as much
Rank Location Existing Condition Recommendation
2 Optimus Heater Personal Heater with Manual Switching Repair heating system so
heater use is eliminated
Installation Cost $1 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $220
Breakeven Cost $1,379 Savings-to-Investment Ratio 1,400 Simple Payback (yr.) 0
Auditors Notes: keep thermostat at a reasonable temperature to avoid having to use space heaters.
Rank Location Existing Condition Recommendation
4 Ceiling Fans Ceiling Fans (2 Fans) with Manual Switching Install timer to turn fans off
when building is unoccupied
Installation Cost $100 Estimated Life of Measure (yr.) 7 Energy Savings (/yr.) $28
6
Breakeven Cost $1,789 Savings-to-Investment Ratio 18 Simple Payback (yr.) 0
Auditors Notes: Change fan schedule to only run while building is occupied.
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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A.3.2 Foundation and/or Crawlspace
It is recommended that the perimeter of the slab be insulated with 2’ of R-10 rigid insulation to
prevent heat from escaping from the edges of the concrete floor. Buildings that use slab heat or
baseboard heaters benefit greatly from this type of insulation due to the close proximity of the
heat supply to the perimeter of the slab.
A.3.3 Roofing and Ceiling
There are no recommended EEM’s in this category. The cost to install new insulation to the
ceiling of the Public Works Building outweighs the energy savings benefits.
A.3.4 Windows
There are no recommended EEM’s in this category. Replacing the windows in order to save
energy is not economical at this time.
A.3.5 Doors
The garage doors in the Public Works Building are not well insulated and can benefit from the
addition of an insulating blanket and new door gaskets. This will double the R-value of the door.
Replacing the doors with better insulated doors is not economical at this time, but adding an
insulating blanket will be cost effective.
Rank Location Existing Condition Recommendation
25
On- or Below-Grade
Floor, Perimeter: 6"
Reinf. Concrete
Insulation for 0' to 2' Perimeter: None
Insulation for 2' to 4' Perimeter: None
Modeled R-Value: 6.7
Install 2' of R-10 rigid board
insulation around perimeter of
Slab (vertical or horizontal),
including a sheet metal cover
Installation Cost $4,332 Estimated Life of Measure (yr.) 30 Energy Savings (/yr.) $228
Breakeven Cost $5,297 Savings-to-Investment Ratio 1.2 Simple Payback (yr.) 19
Rank Location Existing Condition Recommendation
11 Garage Door: Main
Shop- Garage Door
Door Type: 2" sectional door, XPS core, no
thermal break
Insulating Blanket: None
Modeled R-Value: 3.2
Add R-5 insulating blanket to
garage door
Installation Cost $587 Estimated Life of Measure (yr.) 15 Energy Savings (/yr.) $220
Breakeven Cost $2,969 Savings-to-Investment Ratio 5.1 Simple Payback (yr.) 3
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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A.4 Building Heating System / Air Conditioning
A.4.1 Heating and Heat Distribution
The current Domestic Hot Water (DHW) system consists of on 5.5 kW electric water heater with
a 50 gallon storage tank. Replace the existing with an indirect fired water heater that utilizes the
available waste heat to eliminate the need for electricity to heat water. Tying into the current
waste heat system will be economical due to the high price of electricity.
A.4.2 Air Conditioning
The building is not equipped with an air conditioning system.
A.4.3 Ventilation
The ventilation in the Public Works Building is composed of a central Air Handling Unit (AHU)
and exhaust only bathroom fans. The AHU is located in the mezzanine and is designed to
supply heat and fresh air to the all portions of the building. The control system and the dusty air
have caused the AHU to not operate correctly. It is recommended that the AHU be repaired and
brought to full function. It seems likely that the amount of outside air can be limited to the
amount exhausted by the bathroom fans during occupied hours. This is more than the ASHRAE
standard for fresh air in a building at 15 cfm per person.
A.4.4 Air Changes and Air Tightening
No EEMs are recommended in this area because of the difficulty of quantifying the amount of
leaking air and the savings. However, by using a blower door to depressurize the building and
an infra-red camera, the location of significant air leaks can be determined so they can be
repaired.
Rank Location Existing Condition Recommendation
13 Use district hot water to supply heat for DHW
Installation Cost $2,000 Estimated Life of Measure (yr.) 20 Energy Savings (/yr.) $388
Breakeven Cost $5,210 Savings-to-Investment Ratio 2.6 Simple Payback (yr.) 5
Energy Audit – Final Report
Public Works Building
Saint Paul, Alaska
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Appendix B Energy Efficiency Measures that are NOT Recommended
As indicated in other sections of the report, a number of potential EEMs were identified that
were determined to be NOT cost effective by the AkWarm model. These EEMs are not
currently recommended on the basis of energy savings alone because each may only save a
small amount of energy, have a high capital cost, or be expensive to install. While each of
these EEMs is not cost effective at this time, future changes in building use such as longer
operating hours, higher energy prices, new fixtures or hardware on the market, and decreases
in installation effort may make any of these EEMs cost effective in the future. These potential
EEMs should be reviewed periodically to identify any changes to these factors that would
warrant re-evaluation.
Although these upgrades are not currently cost effective on an energy cost basis, the fixtures,
hardware, controls, or operational changes described these EEMs should be considered when
replacing an existing fixture or unit for other reasons. For example, replacing an existing
window with a triple-pane window may not be cost effective based only on energy use, but the if
a window is going to be replaced for some other reason, then the basis for a decision is only the
incremental cost of upgrading from a less efficient replacement window to a more efficient
replacement window. That incremental cost difference will have a significantly shorter payback,
especially since the installation costs are likely to be the same for both units.
The following measures were not found to be cost-effective:
Rank
Feature
Improvement Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio (SIR)
Simple
Payback
(Years)
28 Exterior Door:
Tool Room
Remove existing door and
install standard pre-hung U-
0.16 insulated door, including
hardware.
$34 $821 0.97 24
29
Lighting:
Mezzanine
Storage B
Replace with 4 LED (2) 17W
Module StdElectronic $67 $700 0.81 10
30
Lighting:
Mezzanine
Storage C
Replace with 5 LED (2) 17W
Module StdElectronic $84 $875 0.81 10
31 Lighting: Tool
Room/ EP Shop
Replace with 10 LED (2) 17W
Module StdElectronic $203 $1,750 0.74 8.6
32
Lighting:
Womens
Restroom
Replace with LED (2) 17W
Module StdElectronic $19 $175 0.69 9.1
33 Lighting: Boiler
Room
Replace with 2 LED (2) 17W
Module StdElectronic $34 $350 0.60 10
34 Cathedral
Ceiling: Ceiling
Install R-14 rigid board
insulation. No cost included for
covering insulation.
$2,106 $112,847 0.43 54
35 Lighting:
Mezzanine
Replace with 8 LED (2) 17W
Module StdElectronic $29 $1,400 0.18 48
Energy Audit – Final Report
Public Works Building
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The following measures were not found to be cost-effective:
Rank
Feature
Improvement Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio (SIR)
Simple
Payback
(Years)
36 Lighting: Air
Handler Room
Replace with 4 LED (2) 17W
Module StdElectronic $14 $700 0.18 48
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Appendix C Significant Equipment List
HVAC Equipment
Equipment Manufacturer Model No. Fuel Type Notes
Heat Exchanger Ameridex 93134B District year made:
2001
Water Heater GE SE50M12AAG Electric
Circulation Pump Grundfos UMC 50-40 Electric 1/3 HP
Circulation Pump Grundfos UP 43-75 Electric 1/6 HP
(2) Circulation Pumps Grundfos UMC 50-80 Electric 1/2 HP
Lighting
Location Lighting Type Bulb Type Quantity KWH/YR Cost/YR
Main Shop Metal Halide 400 W 9 7,691 $ 4,153
Outside Metal Halide 250 W 2 3,283 1,773
Front Desk Fluorescent T8 16 2,753 1,487
Outside Metal Halide 100 W 3 1,994 1,077
Tool Room Fluorescent T8 10 860 464
City Admin Office Fluorescent T8 6 826 446
Fred’s Office Fluorescent T8 6 826 446
Conference Room Fluorescent T8 6 774 418
Outside Halogen 75 W 1 440 238
Mezzanine Storage C Fluorescent T8 5 407 220
Stairwell Fluorescent T8 2 344 186
Dmitri Storage Fluorescent T8 2 344 186
Men’s Room Fluorescent T8 2 344 186
Hallway Fluorescent T8 2 344 186
Hallway 2 Fluorescent T8 2 344 186
Mezzanine Storage B Fluorescent T8 4 326 176
Dmitri office Fluorescent T8 2 258 139
Dmitri office Fluorescent T8 1 254 137
Office Mezzanine Fluorescent T8 2 251 135
Main Shop Fluorescent T12 1 230 124
Women’s Restroom Fluorescent T8 1 172 93
Boiler Room Fluorescent T8 2 163 88
Mezzanine Fluorescent T8 8 137 74
Tool Room Fluorescent T12 1 129 70
AHU room Fluorescent T8 4 68 37
Energy Consumption calculated by AkWarm based on wattage, schedule, and an electricity rate of $0.54/kWh
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Plug Loads
Equipment Location Manufacturer KWH/YR Cost/YR
Computer Towers Office Varies 2,642 $ 1,427
Ceiling Fans Shop n/a 1,052 568
Space Heater Office Dayton 1,028 555
Coffee Maker Office Bunn 974 526
Coffee Maker Office n/a 881 476
Battery Backup Office APC 877 474
Space Heater Office Optimus 823 444
Computer Monitors Office Varies 740 400
Doc Center Office Xerox 600 324
Desktop Printer Office Varies 317 171
Radio Charger Shop n/a 263 142
Energy Consumption calculated by AkWarm based on wattage, schedule, and an electricity rate of $0.54/kWh
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Appendix D Local Utility Rate Structure
The information in this section was provided directly from the local utility or gathered from the
local utility’s publicly available information at the time of the audit. All language used in this
section was provided by the local utility and believed to be current at the time of the audit.
Energy use terms, specific fees, and other specific information are subject to change. Updated
rate structure information should be gathered from the utility during future discussion of rates,
rate structures and utility pricing agreements.
City of St. Paul Rate Structure:
The City of St. Paul owns the electric company as well as the buildings that were audited
including the Polar Star, Public Works Building, City Maintenance Building, Fire Station, and
City Hall. The city has a method of internal billing. The building is charged $0.54 per kWh for
all kWh’s below 33,530 which is the amount that the city qualifies for assistance under the
power cost equalization program. After this mark, the electric rate increases.
The waste heat provided to the city buildings by the electric company is free and unmetered.
Utility Charge (kWh charge)
This charge is multiplied by the number of kilowatt-hours (kWh) used in a monthly billing period.
It covers the costs to maintain power plants and substations, interest on loans as well as wires,
power poles and transformers.
Regulatory Charge
This charge of .000492 per kWh is set by the Regulatory Commission of Alaska (RCA). Since
November 1, 1992, the Regulatory Commission of Alaska has been funded by a Regulatory
Charge to the utilities it regulates rather than through the State general fund. The charge,
labeled "Regulatory Cost Charge." on your bill, is set by the RCA, and applies to all retail
kilowatt-hours sold by regulated electric utilities in Alaska.
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Appendix E Analysis Methods
Analysis Methodology
Data collected was processed using AkWarm energy use software to estimate current energy
consumption by end usage and calculate energy savings for each of the proposed energy
efficiency measures (EEMs). In addition, separate analysis may have been conducted to
evaluate EEMs that AkWarm cannot effectively model to evaluate potential reductions in annual
energy consumption. Analyses were conducted under the direct supervision of a Certified
Energy Auditor, Certified Energy Manager, or a Professional Engineer.
EEMs are evaluated based on building use, maintenance and processes, local climate
conditions, building construction type, function, operational schedule and existing conditions.
Energy savings are calculated based on industry standard methods and engineering
estimations. Each model created in AkWarm is carefully compared to existing utility usage
obtained from utility bills. The AkWarm analysis provides a number of tools for assessing the
cost effectiveness of various improvement options. The primary assessment value used in this
audit report is the Savings/Investment Ratio (SIR). The SIR is a method of cost analysis that
compares the total cost savings through reduced energy consumption to the total cost of a
project over its assumed lifespan, including both the construction cost and ongoing maintenance
and operating costs. Other measurement methods include Simple Payback, which is defined as
the length of time it takes for the savings to equal the total installed cost and Breakeven Cost,
which is defined as the highest cost that would yield a Savings/Investment Ratio of one.
EEMs are recommended by AkWarm in order of cost-effectiveness. AkWarm first calculates
individual SIRs for each EEM, and then ranks the EEMs by SIR, with higher SIRs at the top of
the list. An individual EEM must have a SIR greater than or equal to one in order to be
recommended by AkWarm. Next AkWarm modifies the building model to include the installation
of the first EEM and then re-simulates the energy use. Then the remaining EEMs are re-
evaluated and ranked again. AkWarm goes through this iterative process until all suggested
EEMs have been evaluated.
Under this iterative review process, the savings for each recommended EEM is calculated
based on the implementation of the other, more cost effective EEMs first. Therefore, the
implementation of one EEM affects the savings of other EEMs that are recommended later.
The savings from any one individual EEM may be relatively higher if the individual EEM is
implemented without the other recommended EEMs. For example, implementing a reduced
operating schedule for inefficient lighting may result in relatively higher savings than
implementing the same reduced operating schedule for newly installed lighting that is more
efficient. If multiple EEMs are recommended, AkWarm calculates a combined savings.
Inclusion of recommendations for energy savings outside the capability of AkWarm will impact
the actual savings from the AkWarm projections. This will almost certainly result in lower
energy savings and monetary savings from AkWarm recommendations. The reality is that only
so much energy is consumed in a building. Energy savings from one EEM reduces the amount
of energy that can be saved from additional EEMs. For example, installation of a lower wattage
light bulb does not save energy or money if the bulb is never turned on because of a schedule
or operational change at the facility.
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Appendix F Audit Limitations
The results of this audit are dependent on the input data provided and can only act as an
approximation. In some instances, several EEMs or installation methods may achieve the
identified potential savings. Actual savings will depend on the EEM selected, the price of
energy, and the final installation and implementation methodology. Competent tradesmen and
professional engineers may be required to design, install, or otherwise implement some of the
recommended EEMs. This document is an energy use audit report and is not intended as a
final design document, operation, and maintenance manual, or to take the place of any
document provided by a manufacturer or installer of any device described in this report.
Cost savings are calculated based on estimated initial costs for each EEM. Estimated costs
include labor and equipment for the full up-front investment required to implement the EEM.
The listed installation costs within the report are conceptual budgetary estimates and should not
be used as design estimates. The estimated costs are derived from Means Cost Data, industry
publications, local contractors and equipment suppliers, and the professional judgment of the
CEA writing the report and based on the conditions at the time of the audit.
Cost and energy savings are approximations and are not guaranteed.
Additional significant energy savings can usually be found with more detailed auditing
techniques that include actual measurements of electrical use, temperatures in the building and
HVAC ductwork, intake and exhaust temperatures, motor runtime and scheduling, and infrared,
air leakage to name just a few. Implementation of these techniques is the difference between a
Level III Energy Audit and the Level II Audit that has been conducted.
Disclaimer: "This report was prepared as an account of work sponsored by an agency of the
United States Government. Neither the United States Government nor any agency thereof, nor
any of their employees, makes any warranty, express or implied, or assumes any legal liability
or responsibility for the accuracy, completeness, or usefulness of any information, apparatus,
product, or process disclosed, or represents that its use would not infringe privately owned
rights. Reference herein to any specific commercial product, process, or service by trade name,
trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,
recommendation, or favoring by the United States Government or any agency thereof. The
views and opinions of authors expressed herein do not necessarily state or reflect those of the
United States Government or any agency thereof."
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Appendix G References
Although not all documents listed below are specifically referenced in this report, each contains
information and insights considered valuable to most buildings.
Alaska Department of Education and Early Development; Education Support Services/Facilities.
(1999). Alaska School Facilities Preventative Maintenance Handbook. Juneau, AK: Alaska
Department of Education and Early Development.
Alaska Housing Finance Corportation. (2010). Retrofit Energy Assessment for Loans. AHFC.
ASHRAE. (1997). 1997 ASHRAE Handbook: Fundamentals. Atlanta, GA: ASHRAE.
ASHRAE. (2007). ASHRAE Standard 105-2007 Expressing and Comparing Building Energy
Performance. Retrieved from ASHRAE: www.ashrae.org
ASHRAE. (2007). ASHRAE Standard 90.1-2007 Energy Standards for buildings Except Low-Rise
Residential Buildings. Retrieved from ASHRAE: www.ashrae.org
ASHRAE. (2010). ASHRAE Standard 62.1-2010 Ventilaton for Acceptable Indoor Air Quality.
Retrieved from ASHRAE: www.ashrae.org
ASHRAE. (2010). ASHRAE Standard 62.2-2010 Ventilation and Acceptable Indoor Air Quality in
Low Rise Residential Buildings. Retrieved from ASHRAE: www.ashrae.org
ASHRAE RP-669 and SP-56. (2004). Procedures for Commercial Building Energy Audits. Atlanta,
GA: ASHRAE.
Coad, W. J. (1982). Energy Engineering and Management for Building Systems. Scarborough,
Ontario, Canada: Van Nostrand Reinhold Company.
Daley, D. T. (2008). The Little Black Book of Reliability Management. New York, NY: Industrial
Press, Inc.
Federal Energy Management Program. (2004, March 3). Demand Controlled Ventilation Using CO2
Sensors. Retrieved 2011, from US DOE Energy Efficiency and Renewable Energy:
http://www.eere.energy.gov/femp/pdfs/fta_co2.pdf
Federal Energy Management Program. (2006, April 26). Low-Energy Building Design Guidelines.
Retrieved 2011, from Department of Energy; Federal Energy Management Program:
http://www.eren.doe.gov/femp/
Institute, E. a. (2004). Variable Speed Pumping: A Guide to Successful Applications. Oxford, UK:
Elsevier Advanced Technology.
International Code Council. (2009). International Energy Conservation Code. Country Club Hills, IL:
International Code Council, Inc.
Leach, M., Lobato, C., Hirsch, A., Pless, S., & Torcellini, P. (2010, September). Technical Support
Document: Strategies for 50% Energy Savings in Large Office Buildings. Retrieved 2011,
from National Renewable Energy Laboratory: http://www.nrel.gov/docs/fy10osti/49213.pdf
Thumann, P.E., C.E.M., A., Younger, C.E.M., W. J., & Niehus, P.E., C.E.M., T. (2010). Handbook of
Energy Audits Eighth Edition. Lilburn, GA: The Fairmont Press, Inc.
U.S. Energy Information Administration. (2006). Commercial Building Energy Consumption Survey
(CBECS). Retrieved 2011, from Energy Information Administration:
http://www.eia.gov/emeu/cbecs/
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Appendix H Typical Energy Use and Cost – Fairbanks and Anchorage
This report provides data on typical energy costs and use on selected building in Fairbanks and
Anchorage, Alaska for comparative purposes only. The values provided by the US Energy
Information Administration CBECS study included a broader range of building types for the
Continental U.S. are not necessarily good comparatives for buildings and conditions in Alaska.
An assortment of values from CBECS may be found in Appendix I.
The Alaska data described in this report came from a benchmarking study NORTECH and other
Technical Services Providers (TSPs) completed on publicly owned buildings in Alaska under
contract with AHFC. This study acquired actual utility data for municipal buildings and schools
in Alaska for the two recent full years. The utility data included costs and quantities including
fuel oil, electricity, propane, wood, steam, and all other energy source usage. This resulted in a
database of approximately 900 buildings. During the course of the benchmarking study, the
comparisons made to the CBECS data appeared to be inappropriate for various reasons.
Therefore, this energy use audit report references the average energy use and energy cost of
Anchorage and Fairbanks buildings as described below.
The Alaska benchmarking data was evaluated in order to find valid comparison data. Buildings
with major energy use information missing were eliminated from the data pool. After detailed
scrutiny of the data, the most complete information was provided to NORTECH by the
Fairbanks North Star Borough School District (FNSBSD) and the Anchorage School District
(ASD). The data sets from these two sources included both the actual educational facilities as
well as the district administrative buildings and these are grouped together in this report as
Fairbanks and Anchorage schools. These two sources of information, being the most complete
and reasonable in-state information, have been used to identify an average annual energy
usage for Fairbanks and for Anchorage in order to provide a comparison for other facilities in
Alaska.
Several factors may limit the comparison of a specific facility to these regional indicators. In
Fairbanks, the FNSBSD generally uses number two fuel oil for heating needs and electricity is
provided by Golden Valley Electric Association (GVEA). GVEA produces electricity from a coal
fired generation plant with additional oil generation upon demand. A few of the FNSBSD
buildings in this selection utilize district steam and hot water. The FNSBSD has recently (the
last ten years) invested significantly in envelope and other efficiency upgrades to reduce their
operating costs. Therefore a reader should be aware that this selection of Fairbanks buildings
has energy use at or below average for the entire Alaska benchmarking database.
Heating in Anchorage is through natural gas from the nearby natural gas fields. Electricity is
also provided using natural gas. As the source is nearby and the infrastructure for delivery is in
place, energy costs are relatively low in the area. As a result, the ASD buildings have lower
energy costs, but higher energy use, than the average for the entire benchmarking database.
These special circumstances should be considered when comparing the typical annual energy
use for particular buildings.
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Appendix I Typical Energy Use and Cost – Continental U.S.
This report references the Commercial Buildings Energy Consumption Survey (CBECS),
published by the U.S. Energy Information Administration in 2006. Initially this report was
expected to compare the annual energy consumption of the building to average national energy
usage as documented below. However, a direct comparison between one specific building and
the groups of buildings outlined below yielded confusing results. Instead, this report uses a
comparative analysis on Fairbanks and Anchorage data as described in Appendix F. An
abbreviated excerpt from CBECS on commercial buildings in the Continental U.S. is below.
Released: Dec 2006
Next CBECS will be conducted in 2007
Table C3. Consumption and Gross Energy Intensity for Sum of Major Fuels for Non-Mall Buildings, 2003
All Buildings* Sum of Major Fuel Consumption
Number of
Buildings
(thousand)
Floor space
(million
square feet)
Floor space
per Building
(thousand
square feet)
Total
(trillion
BTU)
per
Building
(million
BTU)
per
Square
Foot
(thousand
BTU)
per
Worker
(million
BTU)
All Buildings* 4,645 64,783 13.9 5,820 1,253 89.8 79.9
Building Floor space (Square Feet)
1,001 to 5,000 2,552 6,789 2.7 672 263 98.9 67.6
5,001 to 10,000 889 6,585 7.4 516 580 78.3 68.7
10,001 to 25,000 738 11,535 15.6 776 1,052 67.3 72.0
25,001 to 50,000 241 8,668 35.9 673 2,790 77.6 75.8
50,001 to 100,000 129 9,057 70.4 759 5,901 83.8 90.0
100,001 to 200,000 65 9,064 138.8 934 14,300 103.0 80.3
200,001 to 500,000 25 7,176 289.0 725 29,189 101.0 105.3
Over 500,000 7 5,908 896.1 766 116,216 129.7 87.6
Principal Building Activity
Education 386 9,874 25.6 820 2,125 83.1 65.7
Food Sales 226 1,255 5.6 251 1,110 199.7 175.2
Food Service 297 1,654 5.6 427 1,436 258.3 136.5
Health Care 129 3,163 24.6 594 4,612 187.7 94.0
Inpatient 8 1,905 241.4 475 60,152 249.2 127.7
Outpatient 121 1,258 10.4 119 985 94.6 45.8
Lodging 142 5,096 35.8 510 3,578 100.0 207.5
Retail (Other Than Mall) 443 4,317 9.7 319 720 73.9 92.1
Office 824 12,208 14.8 1,134 1,376 92.9 40.3
Public Assembly 277 3,939 14.2 370 1,338 93.9 154.5
Public Order and Safety 71 1,090 15.5 126 1,791 115.8 93.7
Religious Worship 370 3,754 10.1 163 440 43.5 95.6
Service 622 4,050 6.5 312 501 77.0 85.0
Warehouse and Storage 597 10,078 16.9 456 764 45.2 104.3
Other 79 1,738 21.9 286 3,600 164.4 157.1
Vacant 182 2,567 14.1 54 294 20.9 832.1
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Appendix J List of Conversion Factors and Energy Units
1 British Thermal Unit is the energy required to raise one pound of water one degree F°
1 Watt is approximately 3.412 BTU/hr
1 horsepower is approximately 2,544 BTU/hr
1 horsepower is approximately 746 Watts
1 "ton of cooling” is approximately 12,000 BTU/hr, the amount of power required to
melt one short ton of ice in 24 hours
1 Therm = 100,000 BTU
1 KBTU = 1,000 BTU
1 KWH = 3413 BTU
1 KW = 3413 BTU/Hr
1 Boiler HP = 33,400 BTU/Hr
1 Pound Steam = approximately 1000 BTU
1 CCF of natural gas = approximately 1 Therm
1 inch H2O = 250 Pascal (Pa) = 0.443 pounds/square inch (psi)
1 atmosphere (atm) = 10,1000 Pascal (Pa)
BTU British Thermal Unit
CCF 100 Cubic Feet
CFM Cubic Feet per Minute
GPM Gallons per minute
HP Horsepower
Hz Hertz
kg Kilogram (1,000 grams)
kV Kilovolt (1,000 volts)
kVA Kilovolt-Amp
kVAR Kilovolt-Amp Reactive
KW Kilowatt (1,000 watts)
KWH Kilowatt Hour
V Volt
W Watt
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Appendix K List of Acronyms, Abbreviations, and Definitions
ACH Air Changes per Hour
AFUE Annual Fuel Utilization Efficiency
Air Economizer A duct, damper, and automatic control system that
allows a cooling system to supply outside air to reduce
or eliminate the need for mechanical cooling.
Ambient Temperature Average temperature of the surrounding air
Ballast A device used with an electric discharge lamp to cause
the lamp to start and operate under the proper circuit
conditions of voltage, current, electrode heat, etc.
CO2 Carbon Dioxide
CUI Cost Utilization Index
CDD Cooling Degree Days
DDC Direct Digital Control
EEM Energy Efficiency Measure
EER Energy Efficient Ratio
EUI Energy Utilization Index
FLUOR Fluorescent
Grade The finished ground level adjoining a building at the
exterior walls
HDD Heating Degree Days
HVAC Heating, Ventilation, and Air-Conditioning
INCAN Incandescent
NPV Net Present Value
R-value Thermal resistance measured in BTU/Hr-SF-̊F (Higher
value means better insulation)
SCFM Standard Cubic Feet per Minute
Savings to Investment Ratio (SIR) Savings over the life of the EEM divided by Investment
capital cost. Savings includes the total discounted dollar
savings considered over the life of the improvement.
Investment in the SIR calculation includes the labor and
materials required to install the measure.
Set Point Target temperature that a control system operates the
heating and cooling system
Simple payback A cost analysis method whereby the investment cost of
an EEM is divided by the first year’s savings of the EEM
to give the number of years required to recover the cost
of the investment.
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Appendix L Building Floor Plan
Floor plans by NORTECH based on drawings provided by City of St. Paul. N