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ENERGY AUDIT – FINAL REPORT
TANACROSS SCHOOL
1 Mile Tanacross Road
Tanacross, Alaska
Prepared for:
Mr. Randy Warren
PO Box 226
Tok, Alaska
Prepared by:
David C. Lanning PE, CEA
Steven Billa EIT, CEAIT
July 11, 2012
Acknowledgment: “This material is based upon work supported by the Department of
Energy under Award Number DE-EE0000095”
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 ....................................................................................................... 6
2.2.1 Total Energy Use and Cost of 2010 ........................................................... 7
2.2.2 Energy Utilization Index of 2010 ................................................................ 8
2.2.3 Cost Utilization Index of 2010 .................................................................... 9
2.2.4 Seasonal Energy Use Patterns ................................................................ 10
2.2.5 Future Energy Monitoring ........................................................................ 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 Tanacross School .......................... 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
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Tanacross, Alaska
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APPENDICES
Appendix A Recommended Energy Efficiency Measures ........................................... 19
Appendix B Energy Efficiency Measures that are NOT Recommended ..................... 25
Appendix C Significant Equipment List ....................................................................... 26
Appendix D Local Utility Rate Structure ...................................................................... 27
Appendix E Analysis Methodology .............................................................................. 29
Appendix F Audit Limitations ...................................................................................... 30
Appendix G References .............................................................................................. 31
Appendix H Typical Energy Use and Cost – Fairbanks and Anchorage ..................... 32
Appendix I Typical Energy Use and Cost – Continental U.S. .................................... 33
Appendix J List of Conversion Factors and Energy Units .......................................... 34
Appendix K List of Acronyms, Abbreviations, and Definitions .................................... 35
Appendix L Building Floor Plan .................................................................................. 36
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1.0 EXECUTIVE SUMMARY
NORTECH has completed an ASHRAE Level II Energy Audit of the Tanacross School, a 7,538
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 October 26, 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 and potential savings 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 Tanacross
School. 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.
PRIORITY LIST – ENERGY EFFICIENCY MEASURES (EEMs)
Rank Feature/
Location Improvement Description
Estimated
Annual
Energy
Savings
Estimated
Installed
Cost
Savings to
Investment
Ratio, SIR
Simple
Payback
(Years)
1
Setback
Thermostat:
Tanacross
School
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Tanacross School space.
$1,332 $350 52 0.3
2 Lighting: 2
Exterior Lights
Replace with 2 LED 20W
Module StdElectronic $110 $110 17 1.0
3
Setback
Thermostat:
Gymnasium
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Gymnasium space.
$412 $350 16 0.9
4
Lighting: Class
104, 107 Girls
Locker, 108 Boys
Locker, 113
Replace with 6 FLUOR CFL, A
Lamp 15W $26 $18 12 0.7
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PRIORITY LIST – ENERGY EFFICIENCY MEASURES (EEMs)
5
On- or Below-
Grade Floor,
Perimeter:
Crawlspace
Perimeter
Install R-19 Fiberglass Batts
on the Perimeter 4 feet of the
Crawl Space Floor.
$798 $2,441 7.7 3.1
6 Lighting: 109,
110, 111, 114
Replace with 10 LED (2) 17W
Module StdElectronic $415 $1,750 3.3 4.2
7 Lighting: Room
120
Replace with 9 LED (2) 17W
Module StdElectronic $270 $1,575 2.4 5.8
8 Lighting: Exterior Replace with 7 LED 35W
Module StdElectronic $548 $4,550 2.1 8.3
9 Lighting: Room
122
Replace with 16 LED (2) 17W
Module StdElectronic $385 $2,800 1.9 7.3
10 HVAC And DHW
replace furnace 1 motor with a
more efficient and furnace 2
motor with a smaller sized
motor, install vent damper,
apply mastic to ducts in
crawlspace
$1,086 $10,000 1.9 9.2
11
Lighting: Rooms
101, 107 Girls
Locker, 108 Boys
Locker, 119, 121
Replace with 46 LED (2) 17W
Module StdElectronic $841 $8,050 1.5 9.6
12
Window/Skylight:
Sinlge Pane
Wood Other
Replace existing window with
U-0.22 vinyl window $435 $5,721 1.3 13
13
Window/Skylight:
Single Pane
Wood South
Replace existing window with
U-0.22 vinyl window $234 $3,377 1.2 14
TOTAL, cost-effective measures $6,891 $41,092 2.7 6.0
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Modeled Building Energy Cost Breakdown
The charts are a graphical representation of the calculated Energy Cost Breakdown for the
Tanacross School and the calculated Savings from Energy Efficiency Measures that are
previously discussed.
On the existing building, the greatest portions of energy are in Envelope Air Losses and lighting.
This indicates that the greatest savings can probably be found in reducing air leakage up the
chimney and supply ducts and from upgrading lighting. Detailed improvements for ventilation,
air leakage, lighting and other cost effective measures can be found in Appendix A.
The charts breaks down energy cost into the following use categories:
Envelope Air Losses—the cost to provide heated fresh air to occupants, air leakage,
heat lost in air through the chimneys and exhaust fans, heat lost to wind and other
similar losses.
Envelope
o Ceiling—quantified heat loss transferred through the ceiling portion of the
envelope.
o Window—quantified heat loss through the window portion of the envelope.
o Wall/Door—quantified heat loss through the wall and door portions of the
envelope.
o Floor—quantified heat loss through the floor portion of the envelope.
Water Heating—energy cost to provide domestic hot water.
Fans—energy cost to run ventilation, and exhaust fans.
Lighting—energy cost to light the building.
Refrigeration—energy costs to provide refrigerated goods for the occupants.
Other Electrical—includes energy costs not listed above including cooking loads, laundry
loads, other plug loads and electronics.
Envelope
Air Losses
$6,784
22%
Ceiling
$2,885
9%
Window
$1,352
4%Wall/Door
$4,215
14%
Floor
$4,733
15%
Water
Heating
$905
3%
Lighting
$5,761
18%
Refriger-
ation
$2,740
9%
Other
Electrical
$1,831
6%
Clothes
Drying
$75
0%
Existing Building Energy Cost
Breakdown $ 31,281
Envelope
Air Losses
$6,194
20%Ceiling
$2,733
9%
Window
$159
0%
Wall/Door
$3,917
12%Floor
$3,143
10%Water
Heating
$905
3%
Lighting
$2,692
9%
Refrigerati
on
$2,740
9%
Other
Electrical
$1,831
6%
Clothes
Drying
$75
0%
Savings
$6,892
22%
Retrofit Building Energy Cost
Breakdown $ 24,390
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2.0 INTRODUCTION
NORTECH contracted with the Alaska Housing Finance Corporation to perform ASHRAE
Level II Energy Audits for publically owned buildings in Alaska. This report presents the findings
of the utility benchmarking, modeling analysis, and 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
Tanacross School is used as a K-8 school and is composed of classrooms, a gymnasium, and
offices.
2.1.2 Building Occupancy and Schedules
This building is occupied by 30 students and 2 teachers during the school year from the middle
of August to the end of May. Students primarily occupy the building from 8:00 am to 3:30 pm
Monday through Friday and faculty occupies the building from 7:30 am to 4:00 pm.
2.1.3 Building Description
Tanacross School is a one story wood framed building on a crawlspace, constructed in 1982.
Building Envelope
Building Envelope: Walls
Wall Type Description Insulation Notes
Above-grade walls Wood-framed with 2x10 studs
spaced 16-inches on center. R-30 fiberglass batt. No signs of insulation
damage.
Crawlspace walls Wood-framed with 2x6 studs
spaced 16-inches on center.
R-19 fiberglass batt
2-inches of foam
No signs of insulation
damage.
Building Envelope: Floors
Floor Type Description Insulation Notes
Below Grade Floor Closed crawl space with 6 mil
poly vapor barrier None -
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Heating and Ventilation Systems
The heat to this building is provided by two #2 oil fired furnaces:
Furnace-1 provides heat to classrooms and miscellaneous rooms
Furnace-2 provides heat to the gym area
The heat from these furnaces is controlled by one manual thermostat each. The thermostat for
Furnace-1 has a day and night setting.
A unit heater in the shop/craft room has been removed from the building.
Air Conditioning System
No air condition system is installed in the building.
Energy Management
This building does not have any formal energy management equipment.
Lighting Systems
Primary lighting in Tanacross School is provided by fluorescent ceiling mounted fixtures with
T12 lamps (1.5-inch diameter, 4-foot long). The gymnasium uses ceiling mounted fixtures with
175 watt metal halide lamps.
Domestic Hot Water
Domestic hot water is provided by an oil fired hot water heater.
Building Envelope: Roof
Roof Type Description Insulation Notes
All Roofs Cold roofs framed with wood
trusses.
R38 + R19 fiberglass
batt.
No signs of insulation
damage.
Building Envelope: Doors and Windows
Door and Window
Type Description Estimated
R-Value Notes
All Doors Metal 2-inch: Foam Core 5.0 -
Window Type 1 Wood: Double Pane 2.0
Window would benefit
from window film in
winter months
Window Type 2 Wood: Single Pane 1.1
Window would benefit
from window film in
winter months
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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.
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2.2.1 Total Energy Use and Cost of 2010
The energy use profiles below show the energy and cost breakdowns for the Tanacross School.
In 2010, the total annual energy cost for the building was $ 28,980 per year and consumption
was 747,000,000 BTUs including both Fuel Oil and Electricity kWh converted to BTU’s. These
charts show the portion of use for a fuel type and the portion of its cost.
The above charts indicate that the highest portion of energy use is for fuel oil and the highest
portion of cost is for electricity. Fuel oil consumption correlates directly to space heating and
domestic hot water while electrical use can correlate to lighting systems, plug loads, and HVAC
equipment. The energy type with the highest cost often provides the most opportunity for
savings.
Electric,
152
20%
Fuel Oil,
595
80%
Energy Use Total (mmBTU)
Electric,
$18,057
62%
Oil,
$10,923
38%
Energy Cost Total ($)
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2.2.2 Energy Utilization Index of 2010
The primary benchmarking statistic is the Energy Utilization 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 annual usage is then divided by the number of square
feet of the building. The EUI units are BTUs per square foot per year.
The benchmark analysis found that in 2010, the Tanacross School had an EUI of 99,000 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 Tanacross School relative to these values. These findings are discussed further in
Appendix H.
99,000
62,000
123,000
0
20000
40000
60000
80000
100000
120000
140000
Btu/ Sq. FtAnnual Energy Use Index (Total Energy/ SF)
Tanacross School Fairbanks Schools Anchorage Schools
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2.2.3 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 CUI for Tanacross School is about $3.84. This is based on utility costs from 2010 and the
following rates:
Electricity at $0.41/ kWh ($12.01 / Therm)
# 2 Fuel Oil at $2.63 / gallon ($1.88 / 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 Tanacross School relative to these values. More details are
included in Appendix H.
$3.84
$2.42
$2.11
$0.00
$0.50
$1.00
$1.50
$2.00
$2.50
$3.00
$3.50
$4.00
$4.50
Annual Energy Cost Index (Total Cost/ SF)
Tanacross School Fairbanks Schools Anchorage Schools
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2.2.4 Seasonal Energy Use Patterns
Energy consumption is often highly correlated with seasonal climate and usage variations. The
graphs below show the electric and fuel 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 clear relation of increased energy usage during periods of
cold weather can be seen in the months with higher usage.
The fuel deliveries at Tanacross School do not directly relate to the annual fuel consumption.
Analysis of deliveries indicates that tanks are kept partially filled throughout the year to ensure
that the school does not run out of fuel. Based on calculations with Tok heating degree days
(HDDs), the average fuel consumption is around 4,250 gallons/year. The AkWarm model was
modeled to match this value.
0
1,000
2,000
3,000
4,000
5,000
6,000
Jan-09Mar-09May-09Jul-09Sep-09Nov-09Jan-10Mar-10May-10Jul-10Sep-10Nov-10KWHElectrical Consumption
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-10GallonsFuel Oil Deliveries
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2.2.5 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.
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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..
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3.1 Understanding How AkWarm Models Energy Consumption
NORTECH used the AkWarm model for evaluating the overall energy consumption at
Tanacross School. 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.
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3.1.1 AkWarm Calculated Savings for the Tanacross School
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 on 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
Clothes
Drying Total
Existing
Building $19,969 $905 $5,761 $2,740 $1,831 $75 $31,281
With All
Proposed
Retrofits
$16,146 $905 $2,692 $2,740 $1,831 $75 $24,390
Savings $3,823 $0 $3,069 $0 $0 $0 $6,891
Savings in these categories do not reflect interaction with other categories. So, for example, the
savings in lighting does not affect the added space heating cost to make up for the heat saved
in replacing less-efficient lights with more-efficient lights that waste less heat.
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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 and
lighting. 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 directly
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
$5,000
$10,000
$15,000
$20,000
$25,000
$30,000
$35,000
Existing Retrofit
Space Heating
Refrigeration
Other Electrical
Lighting
Domestic Hot Water
Clothes Drying
Annual Energy Costs by End Use
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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 Tanacross School could be modeled well in AKWarm. Retrofits for the HVAC system were
adequately modeled in AkWarm and did not require additional calculations.
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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.
Operations and Maintenance staff implementing a properly designed O & M plan will:
Track and document
o Renovations and repairs,
o Utility bills and fuel consumption, and
o System performance.
Keep available for reference
o A current Building Operating Plan including an inventory of installed systems,
o The most recent available as-built drawings,
o Reference manuals for all installed parts and systems, and
o An up-to-date inventory of on-hand replacement parts.
Provide training and continuing education for maintenance personnel.
Plan for commissioning and re-commissioning at appropriate intervals.
Commissioning of a building is the verification that the HVAC systems perform within the design
or usage ranges of the Building Operating Plan. 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 occupants of Tanacross School report uneven heat distribution to the classrooms. The
heating system needs to be rebalanced. This can be done by having a balancing contractor
permanently adjusting air flow through the floor registers in order to distribute heated air as
necessary.
It is recommended that exposed heating ducts in the crawlspace be sealed with mastic in order
to reduce the amount of possible heat leakage.
Weather-stripping on the doors and windows should be regularly inspected and replaced as
needed.
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APPENDICES
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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
Two programmable thermostats should be installed in Tanacross School. Programmable
electronic thermostats allow for automatic temperature setback, which reduce usage more
reliably than manual setbacks. Reduction of the nighttime temperature set point in the
classrooms and gymnasium will decrease the energy usage.
Rank Building Space Recommendation
1 Tanacross School
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Tanacross School space.
Installation Cost $350 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $1,332
Breakeven Cost $18,061 Savings-to-Investment Ratio 52 Simple Payback yrs 0
Rank Building Space Recommendation
3 Gymnasium
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Gymnasium space.
Installation Cost $350 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $412
Breakeven Cost $5,580 Savings-to-Investment Ratio 16 Simple Payback yrs 1
Energy Audit – Final Report
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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.
The existing exterior lights use high amounts of wattage and should be replaced. A common
retrofit for exterior lighting is LED wall packs. These fixtures will allow or similar levels of light at
a much lower energy use.
All instances of incandescent lamps should be replaced with more efficient compact fluorescent
lamps (CFLs). CFLs offer similar lighting as much lower energy use.
Rank Location Existing Condition Recommendation
2 Exterior 2 INCAN A Lamp, Halogen 75W with
Manual Switching
Replace with 2 LED 20W Module
StdElectronic
Installation Cost $110 Estimated Life of Measure (yrs) 25 Energy Savings (/yr) $110
Breakeven Cost $1,882 Savings-to-Investment Ratio 17 Simple Payback yrs 1
Rank Location Existing Condition Recommendation
8 Exterior 7 HPS 100 Watt StdElectronic with Manual
Switching
Replace with 7 LED 35W
Module StdElectronic
Installation Cost $4,550 Estimated Life of Measure (yrs) 25 Energy Savings (/yr) $548
Breakeven Cost $9,346 Savings-to-Investment Ratio 2.1 Simple Payback yrs 8
Rank Location Existing Condition Recommendation
4
Class 104, 107 Girls
Locker, 108 Boys
Locker, 113
6 INCAN A Lamp, Halogen 75W with
Manual Switching
Replace with 6 FLUOR CFL, A
Lamp 15W
Installation Cost $18 Estimated Life of Measure (yrs) 10 Energy Savings (/yr) $26
Breakeven Cost $217 Savings-to-Investment Ratio 12 Simple Payback yrs 1
Energy Audit – Final Report
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The primary existing lighting in the majority of the school is ceiling mounted fluorescent fixtures
with T12 lamps. Tanacross School experiences high costs of electricity and these inefficient
lamps should be replaced. Along with the high energy usage, most of the rooms in the school
are over-lit. The existing 34 watt T12 lamps can easily be replaced with 17 watt LED lamps.
LED lamps result in a light difference of about 10 percent when compared to current 40 watt
T12 lamps, but this should not be an issue with the current lighting levels.
A.2.2 Other Electrical Loads
No EEMs are recommended in this area as there aren’t any significant plug loads in Tanacross
School.
Rank Location Existing Condition Recommendation
6 109, 110, 111, 114 10 FLUOR (2) T12 4' F40T12 40W
Standard Magnetic with Manual Switching
Replace with 10 LED (2) 17W
Module StdElectronic
Installation Cost $1,750 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $415
Breakeven Cost $5,781 Savings-to-Investment Ratio 3.3 Simple Payback yrs 4
Rank Location Existing Condition Recommendation
7 Room 120 9 FLUOR (2) T12 4' F40T12 34W Energy-
Saver EfficMagnetic with Manual Switching
Replace with 9 LED (2) 17W
Module StdElectronic
Installation Cost $1,575 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $270
Breakeven Cost $3,748 Savings-to-Investment Ratio 2.4 Simple Payback yrs 6
Rank Location Existing Condition Recommendation
9 Room 122 16 FLUOR (2) T12 4' F40T12 34W Energy-
Saver EfficMagnetic with Manual Switching
Replace with 16 LED (2) 17W
Module StdElectronic
Installation Cost $2,800 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $385
Breakeven Cost $5,352 Savings-to-Investment Ratio 1.9 Simple Payback yrs 7
Rank Location Existing Condition Recommendation
11
Rooms 101, 107
Girls Locker, 108
Boys Locker, 119,
121
46 FLUOR (2) T12 4' F40T12 34W Energy-
Saver EfficMagnetic with Manual Switching
Replace with 46 LED (2) 17W
Module StdElectronic
Installation Cost $8,050 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $841
Breakeven Cost $11,736 Savings-to-Investment Ratio 1.5 Simple Payback yrs 10
Energy Audit – Final Report
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A.3 Building Envelope: Recommendations for change
A.3.1 Exterior Walls
No EEMs are recommended in this area because additional insulation is not economical at this
time.
A.3.2 Foundation and/or Crawlspace
Tanacross School can save energy by insulating the perimeter of the crawlspace floor. This is a
method recently developed to save additional energy and keep the crawlspace warmer.
A.3.3 Roofing and Ceiling
No EEMs are recommended in this area because the existing roof already has a sufficient
amount of roof insulation and additional insulation is not economical at this time.
A.3.4 Windows
Window retrofits typically do not pay off as they are costly to install. However, Tanacross
School has a few single pane windows. These should be replaced as they off very little
insulation value and produce significant air leakage.
Rank Location Existing Condition Recommendation
5
On- or Below-Grade
Floor, Perimeter:
Crawlspace
Perimeter
Insulation for 0' to 2' Perimeter: None
Insulation for 2' to 4' Perimeter: None
Modeled R-Value: 12.4
Install R-19 Poly-Wrapped
Fiberglass Batts on the
Perimeter 4 feet of the Crawl
Space Floor.
Installation Cost $2,441 Estimated Life of Measure (yrs) 30 Energy Savings (/yr) $798
Breakeven Cost $18,899 Savings-to-Investment Ratio 7.7 Simple Payback yrs 3
Rank Location Existing Condition Recommendation
12
Window/Skylight:
Single Pane Wood
Other
Glass: Single, Glass
Frame: Wood\Vinyl
Spacing Between Layers: Half Inch
Gas Fill Type: Air
Modeled U-Value: 0.94
Solar Heat Gain Coefficient including
Window Coverings: 0.52
Replace existing window with U-
0.22 vinyl window
Installation Cost $5,721 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $435
Breakeven Cost $7,569 Savings-to-Investment Ratio 1.3 Simple Payback yrs 13
Energy Audit – Final Report
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A.3.5 Doors
No EEMs are recommended in this area because the existing doors already have a sufficient
amount of insulation value.
A.4 Building Heating System / Air Conditioning
A.4.1 Heating and Heat Distribution
Tanacross School’s heating system currently consists of two oil fired furnaces. These furnaces
are old and do not have the high efficiency that some new furnaces offer today. However, due
to Tanacross School’s low usage of oil and need for heat, replacing these furnaces will not be
cost effective at this time. The following measures are recommended:
The existing furnace fan motors have low efficiencies and should be replaced with high
efficiency motors with an efficiency of 84% or higher.
A vent damper should be installed in the chimney connector to reduce standby losses
from the furnaces.
Mastic should be installed on heating ducts in the crawlspace to increase heat
distribution efficiency.
The furnaces should be taken apart and cleaned.
Air exchangers in the furnaces should be inspected and replaced if necessary.
A.4.2 Air Conditioning
NO EEMs are recommended in this area because there are no air conditioning units present in
Tanacross School.
Rank Location Existing Condition Recommendation
13
Window/Skylight:
Single Pane Wood
South
Glass: Single, Glass
Frame: Wood\Vinyl
Spacing Between Layers: Half Inch
Gas Fill Type: Air
Modeled U-Value: 0.94
Solar Heat Gain Coefficient including
Window Coverings: 0.52
Replace existing window with U-
0.22 vinyl window
Installation Cost $3,377 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $234
Breakeven Cost $4,072 Savings-to-Investment Ratio 1.2 Simple Payback yrs 14
Rank Recommendation
10
replace furnace 1 motor with a more efficient and furnace 2 motor with a smaller sized motor, install
vent damper, seal ducts in crawlspace with mastic, take apart and clean furnaces, inspect air
exchanger and replace if necessary
Installation Cost $10,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $1,086
Breakeven Cost $18,728 Savings-to-Investment Ratio 1.9 Simple Payback yrs 9
Energy Audit – Final Report
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A.4.3 Ventilation
No EEMs are recommended in this area because the furnaces are currently using a minimum
amount of outside air for the amount of occupants.
A.4.4 Air Changes and Air Tightening
No EEMs are recommended in this area because of the difficultly of quantifying the amount of
leaking air and the savings. However, using a blower door test with an infra-red camera, the
location of significant leaks can be determined and repaired.
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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 in 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 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/Location Improvement Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio, SIR
Simple
Payback
(Years)
14 Window/Skylight:
Gym
Replace existing window with
U-0.22 vinyl window $5 $138 0.60 29
15 Window/Skylight: Dbl
Wd >3/8 Other
Replace existing window with
U-0.22 vinyl window $19 $536 0.60 29
16 Lighting: Rooms 112,
113, 116, 117, 118
Replace with 12 LED (2) 17W
Module StdElectronic $48 $2,100 0.32 44
17 Lighting: 102, 105,
106, 115
Replace with 8 LED (2) 17W
Module StdElectronic $11 $1,400 0.11 120
18 Lighting: Gym
Replace with 16 FLUOR T5
45.2" F54W/T5 HO Energy-
Saver HighEfficElectronic
$165 $16,000 0.08 97
Energy Audit – Final Report
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Appendix C Significant Equipment List
HVAC Equipment
Equipment Manufacturer Model No. Fuel Type Estimated
Efficiency Notes
Furnace 1 Jackson & Church SDF-20-02F #2 Oil 74% Input Rating:
315,000 BTU/hr
Furnace 2 Jackson & Church SDF-30 #2 Oil 74% Input Rating:
375,000 BTU/hr
Furnace 1 Motor n/a GR5KCR492G43AY Electric 75% 1.5 HP, 1725 RPM
Furnace 2 Motor Leland F XM-0038 Electric 74% 3 HP, 1740 RPM
Water Heater Bock 51E #2 Oil 80% 50 Gallon
Lighting
Location Lighting Type Bulb Type Quantity KWH/YR Cost/YR.
101, 107, 108, 119, 121 Fluorescent T12 46 4,727 $ 1,937
122 Fluorescent T12 16 2,192 899
Exterior HPS 100W 7 2,117 868
109, 110, 111, 114 Fluorescent T12 10 1,938 795
120 Fluorescent T12 9 1,553 637
Gym Metal Halide 175W 16 692 284
Energy Consumption calculated by AkWarm based on wattage, schedule, and an electricity rate of $0.41/kWh
Plug Loads
Equipment Location Manufacturer KWH/YR Cost/YR.
Refrigerators (qty: 6) School Varies 6,684 $ 2,740
Engine Block Heaters Exterior n/a 1,145 469
Laptops School Varies 925 379
Computer Towers School n/a 898 368
Computer Monitors School n/a 449 184
Smart Board Setups School Smart Board 528 216
Energy Consumption calculated by AkWarm based on wattage, schedule, and an electricity rate of $0.41/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.
Tanacross School classifies under Alaska Power Company’s A-1 General Service.
Alaska Power Company Rate Structure:
A-1 General Service
Base Rate $0.3391 / KWH
Customer Charge $12.46
Utility Charge $0.08712 / KWH
Energy Charge $0.3529 / KWH
RCC (Regulatory Charge) $0.000492 / KWH
Overall Rate $0.6925 / KWH
Alaska Power Company offers their customers in a series of different rates, depending on the
classification of the service provided. The rates start at the lowest level, A-1 and work up to A-
5. A-1 is the only classification that does not get charged for demand.
General Service rates break down as follows:
A-1 Service Services under 25,000 KWH of usage per billing cycle
A-2 – A-5 Services Services 25,000 KWH and higher of usage per billing cycle
Customer Charge
A flat fee that covers costs for meter reading, billing and customer service.
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.
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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 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.
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
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.
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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 plan drawn by NORTECH based on field measurements