HomeMy WebLinkAboutORT Walter Northway School 2012-EEManaging Office
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ENERGY AUDIT – FINAL REPORT
WALTER NORTHWAY SCHOOL
7 Mile Village Road
Northway, Alaska
Prepared for:
Mr. Randy Warren
PO Box 226
Tok, Alaska
Prepared by:
Douglas Dusek 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 .................................................................................................. 2
2.0 INTRODUCTION ............................................................................................................... 5
2.1 Building Use, Occupancy, Schedules and Description .......................................... 5
2.1.1 Building Use............................................................................................... 5
2.1.2 Building Occupancy and Schedules .......................................................... 5
2.1.3 Building Description ................................................................................... 6
2.2 Benchmarking ....................................................................................................... 8
2.2.1 Total Energy Use and Cost of 2010 ........................................................... 9
2.2.2 Energy Utilization Index of 2012 .............................................................. 10
2.2.3 Cost Utilization Index ............................................................................... 11
2.2.4 Seasonal Energy Use Patterns ................................................................ 12
2.2.5 Future Energy Monitoring ........................................................................ 13
3.0 ENERGY CONSUMPTION AND MODELING RESULTS .............................................. 14
3.1 Understanding How AkWarm Models Energy Consumption ............................... 15
3.1.1 AkWarm Calculated Savings for the Walter Northway School ................ 16
3.1.2 AkWarm Projected Energy Costs after Modifications .............................. 17
3.2 Energy Efficiency Measures Calculated Outside AkWarm .................................. 18
4.0 BUILDING OPERATION AND MAINTENANCE (O & M) .............................................. 19
4.1 Operations and Maintenance .............................................................................. 19
4.2 Building Specific Recommendations ................................................................... 19
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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APPENDICES
Appendix A Recommended Energy Efficiency Measures ........................................... 21
Appendix B Energy Efficiency Measures that are NOT Recommended ..................... 28
Appendix C Significant Equipment List ....................................................................... 29
Appendix D Local Utility Rate Structure ...................................................................... 30
Appendix E Analysis Methodology .............................................................................. 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
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Northway, Alaska
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1.0 EXECUTIVE SUMMARY
NORTECH has completed an ASHRAE Level II Energy Audit of the Walter Northway School, a
29,104 square foot facility which includes a separate 450 square foot Sewage Treatment Plant.
The audit began with benchmarking which resulted in a calculation of the energy consumption
per square foot. A site inspection was completed on October 22, 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 Walter
Northway 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: Gym
(AHU 3)
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Gym (AHU 3) space.
$750 $200 50 0.3
2 Ventilation
1) Put exhaust fans on timer
switches to come on with
lights.
2) Fix controls on AHU3 to
minimize outside air when
CO2 level is met.
$28,232 $10,000 38 0.4
3 Other Electrical:
Head Bolt Heater
Remove Manual Switching and
Add new Clock Timer or Other
Scheduling Control
$883 $250 29 0.3
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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)
4 Lighting: Exterior Replace with 4 LED 25W Module
StdElectronic $423 $250 25 0.6
5 Lighting: Rooms
12, 13
Replace with 2 LED (2) 17W
Module StdElectronic $591 $350 25 0.6
6
10 Setback
Thermostats:
Classrooms
(AHU-1 + AHU-2
+ Baseboard)
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for the
Classrooms (AHU-1 + AHU-2 +
Baseboard) space.
$5,698 $4,000 19 0.7
7 HVAC And DHW
Replace motors with more
efficient motors; replace Baldor
circ pump motor 85.5% eff motor
with 91.7% or higher eff ,
replace Grundfos UMC 50-80
with a variable speed pump
equivalent to a Grundfos Magna,
replaced Grundfos UPS 15-42
with Grundfos Alpha, install Vent
dampers to reduce idle loss.
$5,737 $9,500 10 1.7
8 Lighting: Rooms
107
Replace with 3 LED (2) 17W
Module StdElectronic $352 $525 9.8 1.5
9 Lighting: Rooms
2
Replace with LED (2) 17W
Module StdElectronic $101 $175 8.2 1.7
10 Lighting: Rooms
102
Replace with 25 LED (2) 17W
Module StdElectronic $2,528 $4,375 8.2 1.7
11 Lighting: Rooms
8, 12, 13, 22, 23
Replace with 9 LED (2) 17W
Module StdElectronic $772 $1,575 7.2 2.0
12 Lighting: Rooms
111
Replace with 20 LED (4) 17W
Module (2) StdElectronic $2,949 $6,500 6.5 2.2
13 Lighting: Rooms
110
Replace with 20 LED (2) 17W
Module StdElectronic $1,474 $3,500 6.0 2.4
14 Lighting: L1, L2 Replace with 36 LED (3) 17W
Module (2) StdElectronic $3,705 $9,000 5.9 2.4
15
Lighting: Rooms
1, 2, 3, 5, 24, 25,
30, 104, Misc.
Cafeteria Rooms,
Cafeteria
Corridor
Replace with 106 LED (2)17W
Module StdElectronic $6,245 $18,550 4.8 3.0
16 Lighting: Kitchen Replace with 12 LED (3) 17W
Module (2) StdElectronic $756 $3,000 3.6 4.0
17 Lighting: Room
17
Replace with 18 LED 115W
Module StdElectronic $3,662 $18,000 2.9 4.9
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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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)
18 Lighting: Exterior Replace with 2 LED 50W Module
StdElectronic $387 $2,000 2.8 5.2
19 Lighting: Exterior Replace with 6 LED 50W Module
StdElectronic $962 $6,000 2.3 6.2
20 Ceiling w/ Attic:
Original Ceiling
Add R-33 blown cellulose
insulation to attic with Standard
Truss.
$3,861 $41,938 2.1 11
21 Ceiling w/ Attic:
Addition Ceiling
Add R-21 blown cellulose
insulation to attic with Standard
Truss.
$1,625 $30,810 1.2 19
TOTAL, cost-effective measures $71,692 $170,498 6.1 2.4
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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
Walter Northway School is used as a K-12 school and is composed of classrooms, a
gymnasium and offices. Adjacent to the building is a sewage treatment plant that is heated by
the school boiler.
2.1.2 Building Occupancy and Schedules
Walter Northway School has an average of 33 students and 6 faculty members and is open
from the beginning of September 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 6:00 am to
6:00 pm.
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2.1.3 Building Description
Walter Northway School is a wood framed, one-story building on pilings, originally constructed
in 1978. A 14,004 square foot addition in 1981 added on a library, shop, and classrooms.
Building Envelope
Sewage Treatment Plant
This is a one story wood framed building on pilings housing the water treatment tanks.
Building Envelope: Walls
Wall Type Description Insulation Notes
Above-grade walls Wood-framed with 2x8 studs
spaced 16-inches on center.
7.25-inches fiberglass
batt.
No signs of insulation
damage.
Building Envelope: Floors
Floor Type Description Insulation Notes
Original Structure Wood-framed floor joists spaced
16-inches on center.
6-inches fiberglass
batt. -
Additions Wood-framed floor joists spaced
16-inches on center.
12-inches fiberglass
batt. -
Building Envelope: Roof
Roof Type Description Insulation Notes
Original Structure Cold roofs framed with wood
trusses.
6-inches fiberglass
batt. -
Additions Cold roofs framed with wood
trusses.
12-inches fiberglass
batt. -
Building Envelope: Doors and Windows
Door and Window
Type Description Estimated
R-Value Notes
Door Type- 1 Metal: EPS core: ¼ lite glass 3.6 171 square feet
Door Type- 2 Metal Flush: EPS core 5.0 98 square feet
All Windows Wood: Double Pane:
<3/8” glass spacing 2 904 square feet
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Heating and Ventilation Systems
The heat in this building is provided by a pair of oil-fired boilers. Circulation pumps distribute
heat throughout the building to:
Baseboard heaters in classrooms and controlled by 10 manual thermostats placed
throughout the building
Heat coils in Air Handling Units (AHUs)
Unit heaters
Within Walter Northway School, there are four AHUs:
AHU-1 functions as a supply fan and provides ventilation and heat to the classrooms.
AHU-2 returns air back to AHU-1.
AHU-3 provides ventilation and heat to the gymnasium (room 17).
AHU-4 provides make up air to the kitchen.
AHU-1 and AHU-2 are operated from 6:00 am to 6:00 pm during the school year. AHU-3
operates from 6:00 am to 6:00 pm and enters a night setback mode in order to still provide heat
to the gymnasium. AHU-4 is run only when the kitchen exhaust hood is operating.
The Sewage Treatment Plant is heated by two unit heaters.
Air Conditioning System
No air conditioning system is installed in the building; however, economizer cooling is possible
with the existing ventilation system.
Energy Management
A DDC system is installed in Walter Northway School and is able to control the temperature
settings of the AHUs and can be used as an energy management system.
Lighting Systems
Primary lighting in Walter Northway School and the Sewage Treatment Plant is provided by
ceiling mounted fluorescent fixtures with T12 lamps (1.5-inch diameter, 4-foot long). The
gymnasium uses 250 watt metal halide lamps in ceiling mounted fixtures.
Domestic Hot Water
An oil-fired 400 gallon hot water heater is used to provide domestic hot water for the building.
The hot water circulates to ensure that hot water is continuously available throughout the
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.
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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 Walter Northway
School and the Sewage Treatment Plant. The total annual energy use for the building is 4,014
million BTUs (MMBTUs) at a cost of $214,839 per year. 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 oil and the highest portion
of cost is for electric. 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 fuel type with the highest cost often provides the most opportunity for savings.
Electric
757
19%
Oil
3,225
80%
Propane
32
1%
Energy Use Total (MMBTU)
Electric,
$149,157
69%
Oil,
$64,567,
30%
Propane
$1,115
1%
Energy Cost Total
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2.2.2 Energy Utilization Index of 2012
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 the Walter Northway School and the Sewage Treatment
Plant has an EUI of 140,000 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 Walter Northway School relative to these values. These findings are discussed
further in Appendix H.
140,000
62,000
123,000
0
20000
40000
60000
80000
100000
120000
140000
160000
Btu/ Sq. FtAnnual Energy Use Index (Total Energy/ SF)
Northway School Fairbanks Schools Anchorage Schools
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2.2.3 Cost Utilization Index
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 Walter Northway School is about $2.17. This is based on utility costs from 2010 and
the following rates:
Electricity at $0.69 / kWh ($20.22/ Therm)
# Fuel Oil at $2.81 / gallon ($2.10 / Therm)
Propane at $3.15 / gallon ($3.45 / 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 Walter Northway School relative to these values. More details
are included in Appendix H.
$7.50
$2.42 $2.11
$0.00
$1.00
$2.00
$3.00
$4.00
$5.00
$6.00
$7.00
$8.00
Annual Energy Cost Index (Total Cost/ SF)
Northway 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 while the heating fuel baseline often reflects year round heating
loads. 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 Walter Northway School do not directly relate to actual fuel consumption.
Analysis of deliveries indicates that tanks are partially filled throughout the year to ensure that
the school does not run out of fuel. Based on calculations with Northway heating degree days
(HDDs), the average fuel consumption is around 23,000 gallons/year. The AkWarm model was
modeled to match this value.
0
5000
10000
15000
20000
25000
30000
Jun-09Aug-09Oct-09Dec-09Feb-10Apr-10Jun-10Aug-10Oct-10Dec-10Feb-11Apr-11Jun-11KWHElectrical Consumption
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Aug-09Oct-09Dec-09Feb-10Apr-10Jun-10Aug-10Oct-10Dec-10Feb-11Apr-11Jun-11GallonsFuel 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-C model for evaluating the overall energy consumption at Walter
Northway 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, referred to AkWarm-C. Although this report and commercial energy
auditors often refer to AkWarm, the actual model program used for this project is AkWarm-C.
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
Walter Northway School
Northway, Alaska
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3.1.1 AkWarm Calculated Savings for the Walter Northway 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 Refrige
ration
Other
Electrical Cooking Ventilation
Fans
Service
Fees Total Cost
Existing
Building $197,815 $5,570 $48,435 $11,963 $3,833 $4,641 $1,875 $1,690 $275,824
With All
Proposed
Retrofits
$155,379 $5,231 $21,592 $11,819 $2,854 $4,606 $960 $1,690 $204,131
Savings $42,436 $339 $26,843 $144 $979 $36 $915 $0 $71,692
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.
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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3.1.2 AkWarm Projected Energy Costs after Modifications
The AkWarm recommended EEMs appear to result in significant savings in lighting and space
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 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
$50,000
$100,000
$150,000
$200,000
$250,000
$300,000
Existing Retrofit
Service Fees
Ventilation and Fans
Space Heating
Refrigeration
Other Electrical
Lighting
Domestic Hot Water
Cooking
Annual Energy Costs by End Use
Energy Audit – Final Report
Walter Northway School
Northway, 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 Walter Northway School 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
Walter Northway School
Northway, Alaska
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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
Walter Northway School uses a Direct Digital Controller, DDC system, to control AHU
temperatures and run times. During the visit it appeared as if AHU-3 was not properly utilizing
the CO2 sensor as it was taking a large amount of outside air into the building at a low level of
CO2 ppm. The DDC system can save the school money if it is maintained regularly and errors
in operation are found and fixed appropriately.
Weather stripping on the doors and windows should be regularly inspected and replaced as
needed.
Alaska Gateway School District should continue to routinely perform maintenance on the school
as operating costs will be kept at a minimum.
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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APPENDICES
Energy Audit – Final Report
Walter Northway School
Northway, 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
Approximately 10 programmable thermostats should be installed to replace all the existing
thermostats. Programmable thermostats allow for automatic temperature setback, which
reduce usage more reliably than manual setbacks. Reduction of the nighttime temperature set
point in the entire building will decrease the energy usage.
AHU-3 currently sets back the temperature of the gym to 64.0 deg F. Further reducing this
temperature to 60.0 deg F is economical and will produce savings.
Rank Building Space Recommendation
1 Gym (AHU 3)
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Gym (AHU 3) space.
Installation Cost $200 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $750
Breakeven Cost $9,970 Savings-to-Investment Ratio 50 Simple Payback yrs 0
Rank Building Space Recommendation
6 Classrooms (AHU-1 + AHU-2 + Baseboard)
Implement a Heating Temperature
Unoccupied Setback to 60.0 deg F for the
Classrooms (AHU-1 + AHU-2 +
Baseboard) space.
Installation Cost $4,000 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $5,698
Breakeven Cost $75,457 Savings-to-Investment Ratio 19 Simple Payback yrs 1
Energy Audit – Final Report
Walter Northway School
Northway, 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.
The price of electricity in Northway is high in comparison to other cities in Alaska, therefore
switching from the existing 34 watt T12s to more efficient 17 watt LED lamps will produce
significant savings.
Rank Location Existing Condition Recommendation
5 Rooms 12, 13 2 FLUOR (2) T12 4' F40T12 34W Energy-
Saver Magnetic with Manual Switching
Replace with 2 LED (2) 17W
Module StdElectronic
Installation Cost $350 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $591
Breakeven Cost $8,631 Savings-to-Investment Ratio 25 Simple Payback yrs 1
Rank Location Existing Condition Recommendation
8 Rooms 107 3 FLUOR (2) T12 4' F40T12 40W Standard
Magnetic with Manual Switching
Replace with 3 LED (2) 17W
Module StdElectronic
Installation Cost $525 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $352
Breakeven Cost $5,147 Savings-to-Investment Ratio 9.8 Simple Payback yrs 1
Rank Location Existing Condition Recommendation
9 Rooms 2 FLUOR (2) T12 F40T12 40W U-Tube
Standard Magnetic with Manual Switching
Replace with LED (2) 17W
Module StdElectronic
Installation Cost $175 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $101
Breakeven Cost $1,441 Savings-to-Investment Ratio 8.2 Simple Payback yrs 2
Rank Location Existing Condition Recommendation
10 Rooms 102 25 FLUOR (2) T12 4' F40T12 40W
Standard Magnetic with Manual Switching
Replace with 25 LED (2) 17W
Module StdElectronic
Installation Cost $4,375 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $2,528
Breakeven Cost $35,939 Savings-to-Investment Ratio 8.2 Simple Payback yrs 2
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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Rank Location Existing Condition Recommendation
11 Rooms 8, 12, 13,
22, 23
9 FLUOR (2) T12 4' F40T12 34W Energy-
Saver Magnetic with Manual Switching
Replace with 9 LED (2) 17W
Module StdElectronic
Installation Cost $1,575 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $772
Breakeven Cost $11,273 Savings-to-Investment Ratio 7.2 Simple Payback yrs 2
Rank Location Existing Condition Recommendation
12 Rooms 111 20 FLUOR (4) T12 4' F40T12 34W Energy-
Saver (2) Magnetic with Manual Switching
Replace with 20 LED (4) 17W
Module (2) StdElectronic
Installation Cost $6,500 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $2,949
Breakeven Cost $41,922 Savings-to-Investment Ratio 6.4 Simple Payback yrs 2
Rank Location Existing Condition Recommendation
13 Rooms 110 20 FLUOR (2) T12 4' F40T12 34W Energy-
Saver Magnetic with Manual Switching
Replace with 20 LED (2) 17W
Module StdElectronic
Installation Cost $3,500 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $1,474
Breakeven Cost $20,951 Savings-to-Investment Ratio 6.0 Simple Payback yrs 2
Rank Location Existing Condition Recommendation
14 L1, L2 36 FLUOR (3) T12 4' F40T12 34W Energy-
Saver (2) Magnetic with Manual Switching
Replace with 36 LED (3) 17W
Module (2) StdElectronic
Installation Cost $9,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $3,705
Breakeven Cost $52,658 Savings-to-Investment Ratio 5.9 Simple Payback yrs 2
Rank Location Existing Condition Recommendation
15
Rooms 1, 2, 3, 5,
24, 25, 30, 104,
Misc. Cafeteria
Rooms, Cafeteria
Corridor
106 FLUOR (2) T12 4' F40T12 34W
Energy-Saver Magnetic with Manual
Switching
Replace with 106 LED (2)17W
Module StdElectronic
Installation Cost $18,550 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $6,245
Breakeven Cost $88,761 Savings-to-Investment Ratio 4.8 Simple Payback yrs 3
Rank Location Existing Condition Recommendation
16 Kitchen 12 FLUOR (3) T12 4' F40T12 34W Energy-
Saver (2) Magnetic with Manual Switching
Replace with 12 LED (3) 17W
Module (2) StdElectronic
Installation Cost $3,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $756
Breakeven Cost $10,825 Savings-to-Investment Ratio 3.6 Simple Payback yrs 4
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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The existing 250 watt metal halide lamps in the gym use a considerable amount of energy and
should be replaced. LED pendant replacement lamps can be installed which will improve color
rendering and provide significant energy savings.
The existing exterior lights use high amounts of wattage and should be replaced. A common
retrofit for exterior metal halides and high pressure sodium lamps is LED wall packs. These
fixtures will allow for similar levels of light at a much lower energy use.
Rank Location Existing Condition Recommendation
17 Room 17 18 MH 250 Watt StdElectronic with Manual
Switching
Replace with 18 LED 115W
Module StdElectronic
Installation Cost $18,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $3,662
Breakeven Cost $52,028 Savings-to-Investment Ratio 2.9 Simple Payback yrs 5
Rank Location Existing Condition Recommendation
4 Exterior 4 INCAN Reflector, Std 65W BR30 with
Manual Switching
Replace with 4 LED 25W
Module StdElectronic
Installation Cost $250 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $423
Breakeven Cost $6,184 Savings-to-Investment Ratio 25 Simple Payback yrs 1
Rank Location Existing Condition Recommendation
18 Exterior 2 HPS 100 Watt StdElectronic with Manual
Switching
Replace with 2 LED 50W
Module StdElectronic
Installation Cost $2,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $387
Breakeven Cost $5,647 Savings-to-Investment Ratio 2.8 Simple Payback yrs 5
Rank Location Existing Condition Recommendation
19 Exterior 6 MH 150 Watt StdElectronic with Manual
Switching
Replace with 6 LED 50W
Module StdElectronic
Installation Cost $6,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $962
Breakeven Cost $14,062 Savings-to-Investment Ratio 2.3 Simple Payback yrs 6
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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A.2.2 Other Electrical Loads
Head bolt heaters use a considerable amount of energy when vehicles are left plugged in
continuously. Putting the head bolt heaters on clock timers and temperature controls will allow
the vehicles to stay warm enough to start and also save energy.
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
The existing amount of insulation in the exposed floors is insufficient in the original section of
the building. Although adding additional insulation in these areas would result in savings, it is
not recommended at this time due to the risk of creating a second vapor barrier.
A.3.3 Roofing and Ceiling
The existing insulation in the original section of the building is insufficient. Adding cellulose
building to the entire roof to obtain close to an effective R-Value of 50 is economical.
Rank Location Existing Condition Recommendation
3 Head Bolt Heater 3 cars plugged in with Manual Switching
Remove Manual Switching and
Add new Clock Timer or Other
Scheduling Control
Installation Cost $250 Estimated Life of Measure (yrs) 10 Energy Savings (/yr) $39
Breakeven Cost $7,298 Savings-to-Investment Ratio 0.6 Simple Payback (yr) 13
Auditors Notes: Typical strategies for head bolts are:
Above 20 F, turn head bolts off
Temperature lower than 20 F but higher than -20 F, turn head bolts to cycle ½ time on
Temperature lower than -20 F, turn head bolts on full time
Rank Location Existing Condition Recommendation
20 Ceiling w/ Attic:
Original Ceiling
Framing Type: Standard
Framing Spacing: 24 inches
Insulated Sheathing: None
Bottom Insulation Layer: R-22 Batt: FG or
RW, 6.75 inches
Top Insulation Layer: None
Modeled R-Value: 23.8
Add R-33 blown cellulose
insulation to attic with Standard
Truss.
Installation Cost $41,938 Estimated Life of Measure (yrs) 30 Energy Savings (/yr) $3,861
Breakeven Cost $89,148 Savings-to-Investment Ratio 2.1 Simple Payback yrs 11
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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A.3.4 Windows
No EEMs are recommended in this area. An upgrade to the existing windows to better
insulated fiberglass windows was considered but was not economical.
A.3.5 Doors
No EEMs are recommended in this area. An upgrade to the existing doors to better insulated
doors was considered but was not economical.
A.4 Building Heating System / Air Conditioning
A.4.1 Heating and Heat Distribution
Walter Northway School’s heating system currently uses single speed pumps. These pumps
should be replaced with more efficient variable speed pumps comparable to Grundfos Magnas.
These pumps have been shown to save a minimum of 50% of electrical energy over
conventional pumps due to the motor design. Variable speed pumps work well in systems that
experience flow variation, as the pumps are capable of changing speeds and reduced speeds
save energy.
Installing vent dampers in the chimney connectors will reduce boiler standby losses.
A.4.2 Air Conditioning
No EEMs are recommended in this area because there are no air conditioning units present in
Walter Northway School.
Rank Location Existing Condition Recommendation
21 Ceiling w/ Attic:
Addition Ceiling
Framing Type: Standard
Framing Spacing: 24 inches
Insulated Sheathing: None
Bottom Insulation Layer: R-38 Batt: FG or
RW, 12 inches
Top Insulation Layer: None
Modeled R-Value: 36.9
Add R-21 blown cellulose
insulation to attic with Standard
Truss.
Installation Cost $30,810 Estimated Life of Measure (yrs) 30 Energy Savings (/yr) $1,625
Breakeven Cost $37,526 Savings-to-Investment Ratio 1.2 Simple Payback yrs 19
Rank Recommendation
7
Replace motors with more efficient motors; replace Baldor circ. pump motor 85.5% eff motor with
91.7% or higher eff , replace Grundfos UMC 50-80 with a variable speed pump equivalent to a
Grundfos Magna, replaced Grundfos UPS 15-42 with Grundfos Alpha, install Vent dampers to reduce
idle loss.
Installation Cost $9,500 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $5,737
Breakeven Cost $95,613 Savings-to-Investment Ratio 10 Simple Payback yrs 2
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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A.4.3 Ventilation
Exhaust fans in Walter Northway School currently run 24 hours a day. Every amount of air that
is exhausted from the building has to be replaced with outside air that needs to be heated.
Putting these exhaust fans on timer switches and wiring the fans in with the lights reduces
reheat loads and is economical.
Based on field observations, the AHUs in Walter Northway School bring in more air than current
ASHRAE standards require. Outside air that is brought into the building during the winter
months has to be heated to avoid cooling down the building. The outside air should be set to a
level that meets minimum ASHRAE standards to avoid heating unnecessary air. Installing a
CO2 sensor in AHU-2’s ductwork can help control the amount of outside air being brought by
AHU-1 into the building and significant reduce costs. AHU-3 currently has a CO2 sensor;
however, the controls need to be evaluated as they are not operating properly.
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, using a blower door test with an infra-red camera, the
location of significant air leaks can be determined and repaired.
Rank Recommendation
2 Put exhaust fans on timer switches to come on with lights. Fix controls on AHU3 to minimize OSA
when CO2 level is met. Install CO2 sensor in AHU-2 ductwork to control amount of OSA.
Installation Cost $10,000 Estimated Life of Measure (yr) 15 Energy Savings (/yr) $28,232
Breakeven Cost $375,156 Savings-to-Investment Ratio 38 Simple Payback yrs 0
Energy Audit – Final Report
Walter Northway School
Northway, 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 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)
22 Lighting: Room 10, 18 Replace with 3 FLUOR CFL,
A Lamp 20W $2 $15 0.97 6
23
Lighting: Rooms
105A, 108, 109, Adj.
to Concession, Boys
Locker, Concession
Room
Replace with 32 LED (2) 17W
Module StdElectronic $290 $5,600 0.76 19
24 Window/Skylight: Dbl
Wd/Vin >3/8 South
Replace existing window with
U-0.22 vinyl window $858 $22,616 0.65 26
25 Window/Skylight: Dbl
Wd/Vin >3/8 Other
Replace existing window with
U-0.22 vinyl window $1,599 $42,268 0.65 26
26 Lighting: Shop,
Concession Area
Replace with 52 LED (2) 17W
Module StdElectronic $292 $9,100 0.45 31
27
Lighting: Rooms 9,
11, 14, 15, 16, 21,
AHU Rooms
Replace with 28 LED (2) 17W
Module StdElectronic $34 $4,900 0.10 140
28 Lighting: Rooms 6,
Art Room
Replace with 25 LED (2) 17W
Module StdElectronic $25 $4,375 0.08 170
Energy Audit – Final Report
Walter Northway School
Northway, Alaska
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Appendix C Significant Equipment List
HVAC Equipment
Equipment Manufacturer Model No. Fuel Type Estimated
Efficiency Notes
Boiler 1- B1 Burnham V1108 #1 fuel oil 80.0% Estimated input rating:
1,517,000 BTU/hr
Boiler 2- B2 Burnham V1109 #1 fuel oil 80.0% Estimated input rating:
1,517,000 BTU/hr
Circ. Pump 1 Baldore n/a Electric 85.5% 7.5 HP
Circ. Pump 2 Grundfos UMC 50-80 Electric n/a 0.5 HP
Unit Heater Type 1 Trane n/a Electric n/a 1 unit located in
cafeteria
Unit Heater Type 2 Durnham Bush n/a Electric n/a 3 units
Water Heater A.O. Smith COF 400-11 #1 fuel oil 75.0% Estimated input rating:
1,000,000 BTU/hr
AHU-1 Motor n/a n/a Electric n/a 15 HP
AHU-2 Motor A.O. Smith E203 Electric 76.5% 5 HP, 1745 RPM
AHU-3 Motor A.O. Smith E454 Electric 91.0% 15 HP, 1750 RPM
AHU-4 Motor A.O. Smith E103 Electric 82.5% 1 HP, 1745 RPM
Lighting
Equipment Location Manufacturer KWH/YR Cost/YR
Full Size Refrigerators (7) varies varies 11,289 $ 7,8789
Head bolt Heaters exterior n/a 2,435 1,680
Water Coolers (4) varies varies 2,280 1,573
Smart Board Units varies varies 2,435 1,680
Energy Consumption calculated by AkWarm based on wattage, schedule, and an electricity rate of $0.69/kWh
Plug Loads
Location Lighting Type Bulb Type Quantity KWH/YR Cost/Yr.
Rooms 1, 2, 3, 5, 24,
25, 30, 104, Misc.
Cafeteria Rooms,
Cafeteria Corridor
Fluorescent T12 106 15,222 $ 10,503
L1, L2 Fluorescent T12 36 10,182 7,026
Room 17 (Gym) Metal Halide 250W 18 9,560 6,596
Room 111 Fluorescent T12 20 7,180 4,954
Room 102 Fluorescent T12 25 5,447 3,758
Room 110 Fluorescent T12 20 3,590 2,477
Exterior Metal Halide 150W 6 2,301 1,588
Rooms 8, 12, 13, 22, 23 Fluorescent T12 9 1,616 1,115
Rooms 12, 13 Fluorescent T12 2 1,413 975
Exterior Incandescent 65W 4 1,140 787
Energy Consumption calculated by AkWarm based on wattage, schedule, and an electricity rate of $0.69/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.
Walter Northway School classifies under Alaska Power Company’s A-2 General Service
Alaska Power Company Rate Structure:
A-2 General Service
Base Rate $0.3320 / KWH
Customer Charge $84.52
Demand Charge $27.83
Energy Charge $0.3425 / KWH
RCC (Regulatory Charge) $0.000492 / KWH
Overall Rate $0.6749 / 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 kilowatt hours (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
Plan Provided by Alaska Gateway School District