HomeMy WebLinkAboutMTA Mentasta School 2012-EEENERGY AUDIT – FINAL REPORT
Mentasta Lake School
P.O. Box 6039
Mentasta Lake, Alaska
Prepared for:
Mr. Randy Warren
P.O. Box 226
Tok, Alaska
Prepared by:
Douglas S. Dusek, CEA
Steven H. Billa, EIT, CEAIT
July 11, 2012
Acknowledgment: “This material is based upon work supported by the Department of
Energy under Award Number DE-EE0000095
Managing Office
2400 College Road 3105 Lakeshore Dr. Suite 106A 4402 Thane Road
Fairbanks, Alaska 99709 Anchorage, Alaska 99517 Juneau, Alaska 99801
p. 907.452.5688 p. 907.222.2445 p: 907.586.6813
f. 907.452.5694 f. 907.222.0915 f: 907.586.6819
www.nortechengr.com
ENVIRONMENTAL ENGINEERING, HEALTH & SAFETY
Anch: 3105 Lakeshore Dr. Ste 106A, 99517 907.222.2445 Fax: 222.0915
Fairbanks: 2400 College Road, 99709 907.452.5688 Fax: 452.5694
Juneau: 4402 Thane Road, 99801 907.586.6813 Fax: 586.6819
info@nortechengr.com www.nortechengr.com
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY .................................................................................................. 1
2.0 INTRODUCTION ............................................................................................................... 3
2.1 Building Description, Use, Occupancy and Schedules.......................................... 3
2.1.1 Building Use ................................................................................................. 3
2.1.2 Occupancy and Schedules ........................................................................... 3
2.1.2 Building Description ...................................................................................... 3
2.2 Benchmarking ....................................................................................................... 6
2.2.1 Energy Utilization Index of 2010 ................................................................ 7
2.2.2 Cost Utilization Index of 2010 .................................................................... 8
2.2.3 Seasonal Energy Use Patterns .................................................................. 9
2.2.4 Future Energy Monitoring ........................................................................... 10
3.0 ENERGY CONSUMPTION AND MODELING RESULTS .............................................. 11
3.1 Understanding How AkWarm Models Energy Consumption ............................... 12
3.1.1 AkWarm Calculated Savings for the Mentasta Lake School ................... 13
3.1.2 AkWarm Projected Energy Costs after Modifications .............................. 14
3.2 Energy Efficiency Measures Calculated Outside AkWarm .................................. 15
4.0 BUILDING OPERATION AND MAINTENANCE (O & M) .............................................. 16
4.1 Operations and Maintenance .............................................................................. 16
4.2 Building Specific Recommendations ................................................................... 16
Energy Audit – Final Report
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Mentasta Lake, Alaska
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APPENDICES
Appendix A Recommended Energy Efficiency Measures ........................................... 18
Appendix B Energy Efficiency Measures that are NOT Recommended ..................... 24
Appendix C Significant Equipment List ....................................................................... 25
Appendix D Local Utility Rate Structure ...................................................................... 26
Appendix E Analysis Methods .................................................................................... 28
Appendix F Audit Limitations ...................................................................................... 29
Appendix G References .............................................................................................. 30
Appendix H Typical Energy Use and Cost – Fairbanks and Anchorage ..................... 31
Appendix I Typical Energy Use and Cost – Continental U.S. .................................... 32
Appendix J List of Conversion Factors and Energy Units .......................................... 33
Appendix K List of Acronyms, Abbreviations, and Definitions .................................... 34
Appendix L Building Floor Plan .................................................................................. 35
Energy Audit – Final Report
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Mentasta Lake, Alaska
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1.0 EXECUTIVE SUMMARY
NORTECH has completed an ASHRAE Level II Energy Audit of Mentasta Lake School, a
14,155 square foot building with a separate 320 square foot boiler shed. The audit began with
benchmarking which resulted in a calculation of the energy consumption per square foot. A site
inspection was completed on October 27, 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 Mentasta
Lake 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 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 Lighting: Rooms
122, 123 Add new Occupancy Sensor $208 $100 32 0.5
2
Setback
Thermostat:
Mentasta School
Implement a Heating
Temperature Unoccupied
Setback to 62.0 deg F for the
Mentasta School space.
$2,475 $2,000 18 0.8
3 Garage Door:
Garage OHD
Add R-5 insulating blanket to
garage door $103 $154 9.4 1.5
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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 Ventilation
Reduce fresh air into the
building by balancing the
system (reduce fresh air to 15
CFM per occupant), Reduce
time on for exhaust fans in
bathrooms, Reduce on time for
boiler room by installing room
fan thermostat
$5,392 $8,000 9.4 1.5
5 Lighting: Exterior
Lights
Replace with 5 LED 17W
Module StdElectronic and Add
new Daylight Sensor
$1,379 $1,310 9.2 0.9
6
Lighting: Rooms
107, 110, 111,
116,117, 118,
119, 125, 126,
127, Kitchen
Hallway
Replace with 109 LED (3) 17W
Module StdElectronic $8,030 $25,000 4.1 3.1
7
Lighting: Rooms
112, 113
Replace with 24 LED (3) 17W
Module StdElectronic $871 $5,500 2 6.3
8 HVAC And DHW
Replace AHU-1 motor with
premium eff motor, Replace
Grundfos 50-80 with Grundfos
magna or equivalent, remove
Grundfos 15-58 and replace
with ESBE thermic valve,
Replace boilers with a multi
pass boiler
$6,107 $56,000 2 9.2
9 Lighting: Rooms
122, 123
Replace with 6 LED (2) 17W
Module StdElectronic $85 $1,000 11 12
TOTAL, cost-effective measures $24,651 $99,064 3.5 4.0
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Mentasta Lake, Alaska
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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 Description, Use, Occupancy and Schedules
2.1.1 Building Use
The primary use of this building is K-12 education and the building is a composed of
classrooms, a gymnasium, and offices.
2.1.2 Occupancy and Schedules
Thirty students and seven employees occupy Mentasta Lake School Monday-Friday from 8 am -
5 pm. Staff occupies the building from August 1 – Jun 15, while students only occupy the
school from August 22 – May 31.
2.1.2 Building Description
The Mentasta Lake School Building in Mentasta Lake is a wood framed, one story building on a
crawlspace, constructed in 1975 with a later addition. There is a separate 320 square foot,
wood framed Boiler Building with a slab on grade foundation that is underlined in this report.
Various components of the construction are discussed below.
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Building Envelope
Heating and Ventilation Systems
The primary heat source for Mentasta Lake School is a pair of Weil McLain Boilers burning #1
fuel oil. The two boilers are located in the boiler shed, adjacent to the school. Heat is
distributed into the building by baseboard heaters, along with hydronic unit heaters in the shop
area and mechanical rooms. Heating is controlled by means of manual thermostats located in
each room.
Building Envelope: Walls
Wall Type Description Insulation Notes
Main Building
Above-grade Walls
2x8 stud wall with 5/8
gypsum, plywood sheeting,
and metal siding.
R-25 fiberglass
batt.
No signs of insulation
damage.
Main Building
Crawlspace Walls 2x6 Single stud R-19 fiberglass
batt None
Boiler Shed Walls 2x6 Single stud R-19 fiberglass
batt None
Building Envelope: Roof
Roof Type Description Insulation Notes
Main Building Roof Cold roofs framed with wood
trusses.
Two layers of R-
19 fiberglass batt.
No signs of insulation
damage.
Boiler Shed Roof Hot roof framed with wood
beams.
Estimated at R-25
fiberglass batt.
No signs of insulation
damage.
Building Envelope: Doors and Windows
Door and Window Type Description Effective
R-value Notes
Exterior Door type 1 Metal with foam insulation, ½ Lite 3 None
Exterior Door type 2 Flush Metal Door with foam
insulation 5 None
Garage Door 2”sectional door, EPS core, no
thermal break 3 None
Window type 1 Triple pane, wood frame, less than
3/8” air space 2.6 None
Window type 2 Double pane, wood frame, greater
than 3/8” air space 2 None
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Within Mentasta Lake School, there are three air handling units- AHU-1, AHU-2, and AHU-3
respectively.
AHU-1 provides ventilation to the gymnasium
AHU-2 provides ventilation to the library
AHU-3 provides ventilation to the kitchen
There is a heating coil located in each air handling unit.
Cooling System
This facility is not equipped with an air conditioning or a ventilation system that performs
economizer cooling.
Energy Management
Air handling units in Mentasta Lake School are operated on a time schedule to conserve
energy. The two main air handling units, AHU-1 and AHU-2, are operated on an 8 am – 5 pm
Monday-Friday schedule during the school year. AHU-2 was not operating during the audit.
The boilers are equipped with Weil-McLain BCP-3 (Boiler Control Panel) devices. These
devices are able to perform outdoor boiler resets which allow the boilers to use the outside air
temperature as the basis for determining the ideal boiler temperature.
Lighting Systems
A lighting retrofit at Mentasta Lake School was performed four years ago. The previously
existing T-12 (1 ½” diameter) bulbs were replaced with T-8 (1” diameter) bulbs, which are now
found throughout the building in troffer style fixtures. T-5 (5/8” diameter) bulb fixtures are found
in the gym, library, and cafeteria.
Domestic Hot Water
The domestic hot water storage tank is located in the boiler shed along with the boilers. The hot
water recirculates in order to ensure that the 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 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 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 Mentasta Lake School has an EUI of 74,000 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 Mentasta Lake School relative to these values. These findings are discussed further in
Appendix H.
74,000
62,000
123,000
0
20000
40000
60000
80000
100000
120000
140000
Btu/ Sq. FtAnnual Energy Use Index (Total Energy/ SF)
Mentasta Lake School Fairbanks Schools Anchorage Schools
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2.2.2 Cost Utilization Index of 2010
Another benchmarking statistic that is useful is the Cost Utilization Index (CUI), which is the cost
for energy used in the building on a square foot basis per year. The CUI is calculated from the
cost for utilities for a year period. The CUI permits comparison of buildings on total energy cost
even though they may be located in areas with differing energy costs and differing heating
and/or cooling climates. The cost of energy, including heating oil, natural gas, and electricity,
can vary greatly over time and geographic location and can be higher in Alaska than other parts
of the country.
The CUI for Mentasta Lake School is about $4.41. This is based on utility costs from
2010 and the following rates:
Electricity at $0.65 / kWh ($19.04 / Therm)
# 1 Fuel Oil at $2.90 / gallon ($2.16 / Therm)
Propane at $3.20 / gallon ($2.86 / 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 Mentasta Lake School relative to these values. More details are
included in Appendix H.
The CUI for Mentasta Lake School is much higher than that of Fairbanks and Anchorage
schools mainly due to the price difference in electrical cost. The average price of electricity in
2010 for Fairbanks was $0.18 per KW/hr, for Anchorage was $0.09 per KW/hr, compared to
Mentasta Lake’s price of $0.65 per KW/hr.
$4.41
$2.42
$2.11
$0.00
$0.50
$1.00
$1.50
$2.00
$2.50
$3.00
$3.50
$4.00
$4.50
$5.00
Annual Energy Cost Index (2010 Total Cost/ SF)
Mentasta Lake School Fairbanks Schools Anchorage Schools
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2.2.3 Seasonal Energy Use Patterns
Energy consumption is often highly correlated with seasonal climate and usage variations. The
graphs below show the electric and 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 winter months. Propane is used in this building only for
cooking, and its seasonal use is that of the school schedule.
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Aug-09Oct-09Dec-09Feb-10Apr-10Jun-10Aug-10Oct-10Dec-10Feb-11Apr-11KWHElectrical Consumption
0
200
400
600
800
1,000
1,200
1,400
Aug-09Oct-09Dec-09Feb-10Apr-10Jun-10Aug-10Oct-10Dec-10Feb-11Apr-11GallonsFuel Oil Consumption
0
20
40
60
80
100
120
140
160
180
Aug-09Oct-09Dec-09Feb-10Apr-10Jun-10Aug-10Oct-10Dec-10Feb-11Apr-11GallonsPropane Fills
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2.2.4 Future Energy Monitoring
Energy accounting is the process of tracking energy consumption and costs. It is important for
the building owner or manager to monitor and record both the energy usage and cost each
month. Comparing trends over time can assist in pinpointing major sources of energy usage and
aid in finding effective energy efficiency measures. There are two basic methods of energy
accounting: manual and automatic. Manual tracking of energy usage may already be performed
by an administrative assistant: however if the records are not scrutinized for energy use, then
the data is merely a financial accounting. Digital energy tracking systems can be installed. They
display and record real-time energy usage and accumulated energy use and cost. There are
several types which have all of the information accessible via Ethernet browser.
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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 Mentasta
Lake 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 Mentasta Lake 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
recommendation based the Savings/Investment Ratio (SIR), which is defined as ratio of the
savings generated over the life of the EEM divided by the installed cost. Higher SIR values are
better and any SIR above one is considered acceptable. If the SIR of an EEM is below one, the
energy savings will not pay for the cost of the EEM and the EEM is not recommended.
Preferred EEMs are listed by AkWarm in order of the highest SIR.
A summary of the savings from the recommended EEMs are listed in this table.
Description Space
Heating
Water
Heating Lighting Refrigeration Other
Electrical Cooking Clothes
Drying
Ventilation
Fans Total
Existing
Building $23,785 $3,754 $29,956 $4,140 $3,904 $1,200 $108 $826 $67,672
With All
Proposed
Retrofits
$12,549 $2,696 $18,328 $4,140 $3,904 $1,200 $108 $97 $43,021
SAVINGS $11,236 $1,058 $11,627 $0 $0 $0 $0 $729 $24,651
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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 direct
measured. The current energy costs are shown below on the left hand bar of the graph and the
projected energy costs, assuming use of the recommended EEMs, are shown on the right.
This graphical format allows easy visual comparison of the various energy requirements of the
facility. In the event that not all recommended retrofits are desired, the proposal energy savings
can be estimated from visual interpretation from this graph.
$0
$20,000
$40,000
$60,000
$80,000
Existing Retrofit
Ventilation and Fans
Space Heating
Refrigeration
Other Electrical
Lighting
Domestic Hot Water
Cooking
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 Mentasta Lake 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.
Commissioning of a building is the verification that the HVAC systems act within the design or
usage ranges. This process ideally, though seldom, occurs as the last phase in construction.
HVAC system operation parameters degrade from ideal over time due to incorrect maintenance,
improper replacement pumps, changes in facility tenants or usage, changes in schedules, and
changes in energy costs or loads. Ideally, re-commissioning of a building should occur every
five to ten years. This ensures that the HVAC system meets the potentially variable use with
the most efficient means.
4.2 Building Specific Recommendations
The boiler room has an exhaust fan that appears to run continuously. This fan blows air into the
room, which results in a higher pressure forcing more air into the boilers. The extra pressure
produces leaner air to fuel ratios and boiler inefficiencies. It is recommended that the exhaust
fan be reinstalled to exhaust outwards. This will produce a negative pressure in the room
therefore a relief vent will also need to be installed to keep the room pressure neutral. The
exhaust fan can then be put on a thermostat to only run when the boiler room is overheated; this
will prevent the fan from running continuously. Electric and fuel costs will be reduced.
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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
Programmable thermostats should be programmed and/or installed in the classrooms as well as
offices. Programmable thermostats allow for automatic temperature setback, which reduce
energy usage more reliably than manual setbacks. Reduction of the nighttime temperature set
point in the recommended areas will decrease the energy usage during non-occupied time,
reducing energy costs.
Thermostats in Mentasta Lake School are manual thermostats which any occupant can adjust.
By allowing occupants to adjust temperature settings, the heating demand changes day to day.
Keeping the temperature at a minimum common set point that’s within an acceptable comfort
level throughout the building will allow for the boilers to reduce heating loads. Observations of
others schools indicate that occupied set points of around 68 deg F are common.
Rank Building Space Recommendation
2 Mentasta School Implement a Heating Temperature Unoccupied Setback to 62.0 deg F for the
Mentasta School space.
Installation Cost $2,000 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $2,475
Breakeven Cost $35,073 Savings-to-Investment Ratio 18 Simple Payback yrs 1
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A.2 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.
A recent lighting retrofit was already performed in Mentasta Lake School with most T-12’s in the
building being replaced with T-8 bulbs. Although the existing T-8 bulbs are efficient, further
energy can be saved by switching the 32 watt T-8’s with new 17 watt LED bulbs. LED bulbs
result in a light difference of about 10 percent when compared to current 32 watt T-8 bulbs.
This decrease in light should not be an issue as the majority of rooms in the school all had
measured foot candles greater than that of recommended levels. Rooms with high lighting
levels that should be relamped, include rooms; 107, 110, 111, 112, 113, 114, 115, 116, 117,
118, 119, 126, 127, and all hallways.
Other observations that lead to energy savings:
The restrooms and hallways in Mentasta Lake School have lights that stay on for the
entire school day. Installing an occupancy sensor may potentially reduce the on time of
the lamp by 50% or greater.
The existing exterior lights consist of 100 watt high pressure sodium fixtures. These
fixtures may be replaced with 17 watt LED outdoor fixtures with comparable light output.
The following tables reflect the savings associated with replacing the existing bulbs
and/or replacing control method.
Rank Location Existing Condition Recommendation
1 Rooms 122, 123 6 FLUOR (2) T8 4' F32T8 32W Standard
Instant StdElectronic with Manual Switching Add new Occupancy Sensor
Installation Cost $100 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $208
Breakeven Cost $3,197 Savings-to-Investment Ratio 32 Simple Payback yrs 0
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A.3 Building Envelope: Recommendations for change
A.3.1 Exterior Walls
No EEMs are recommended in this area. An upgrade to the exterior walls by adding foam
insulation was considered but was not economic.
A.3.2 Foundation and/or Crawlspace
No EEMs are recommended in this area because be the perimeter of this building is already
insulated and additional insulation was not economic.
Rank Location Existing Condition Recommendation
5 Exterior Lights 5 HPS 100 Watt StdElectronic with
Manual Switching
Replace with 5 LED 17W Module
StdElectronic and Add new
Daylight Sensor
Installation Cost $1,310 Estimated Life of Measure (yrs) 10 Energy Savings (/yr) $1,379
Breakeven Cost $12,056 Savings-to-Investment Ratio 9.2 Simple Payback yrs 1
Rank Location Existing Condition Recommendation
6
Rooms 107, 110,
111, 116,117, 118,
119, 125, 126, 127,
Kitchen Hallway
109 FLUOR (3) T8 4' F32T8 32W Standard
Instant StdElectronic with Manual
Switching
Replace with 109 LED (3) 17W
Module StdElectronic
Installation Cost $25,000 Estimated Life of Measure (yrs) 16 Energy Savings (/yr) $8,030
Breakeven Cost $101,861 Savings-to-Investment Ratio 4.1 Simple Payback yrs 3
Rank Location Existing Condition Recommendation
7 Rooms 112, 113 24 FLUOR (3) T8 4' F32T8 32W Standard
Instant StdElectronic with Manual Switching
Replace with 24 LED (3) 17W
Module StdElectronic
Installation Cost $5,500 Estimated Life of Measure (yrs) 16 Energy Savings (/yr) $871
Breakeven Cost $11,031 Savings-to-Investment Ratio 2.0 Simple Payback yrs 6
Rank Location Existing Condition Recommendation
9 Rooms 122, 123
6 FLUOR (2) T8 4' F32T8 32W Standard
Instant StdElectronic with Manual
Switching
Replace with 6 LED (2) 17W
Module StdElectronic
Installation Cost $1,000 Estimated Life of Measure (yrs) 16 Energy Savings (/yr) $85
Breakeven Cost $1,098 Savings-to-Investment Ratio 1.1 Simple Payback yrs 12
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A.3.3 Roofing and Ceiling
No EEMs are recommended in this area. Adding cellulose insulation to the existing insulation in
the attic was evaluated but additional insulation was not economic.
A.3.4 Windows
No EEMs are recommended in this area. The majority of windows in Mentasta Lake School are
triple pane glass and replacement was not economic.
A.3.5 Doors
The heat loss through a door is proportional to the area of the door; therefore a garage door
loses a large amount of heat. The small increase in the resistance to heat transfer of the
garage door will result in high energy savings. By simply adding an insulation blanket to the
existing door, the R-value will be increased by 5, making it more comparable to the resistance of
industry leading garage doors.
A.4 Building Heating System / Air Conditioning
A.4.1 Heating and Heat Distribution
AHU-1 provides primary heat to the gymnasium. The existing motor in this air handling unit is a
Baldor Industrial motor with a low efficiency of 67%. This air handling unit would use less
electricity by using a more efficient motor.
Distribution pumps for the heating system consist of two Grundfos UPS-50-80/2F pumps.
These pumps may be replaced with “intelligent” pumps such as Grundfos Magnas. This pump
with new type magnets will produce approximately 50% savings.
The existing boiler systems use a Grundfos UPS 15-58 FC pump to recirculate supply water into
the boiler to eliminate thermal shock to the boiler. Replacing this pump with a thermic valve
does the same job without added pumps.
Rank Location Existing Condition Recommendation
3 Garage Door:
Garage OHD
Door Type: 2" sectional door,
EPS core, no thermal break
Insulating Blanket: None
Modeled R-Value: 3
Add R-5 insulating blanket to
garage door
Installation Cost $154 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $103
Breakeven Cost $1,456 Savings-to-Investment Ratio 9.4 Simple Payback yrs 2
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Boiler replacement is estimated at $50,000. If all other recommendations for a heating system
retrofit are considered, annual energy savings are lower but simple payback is shorter.
A.4.2 Air Conditioning
Mentasta Lake School does not currently have an air conditioning system. However, during
times of the year where there is a large number of Cooling Degree Days (CDD), the existing air
handling units can be used to implement economizer cooling. This cooling can be
accomplished by completely opening outside air dampers in the AHU’s, and mixing little to no
return air. This will cool the building using the colder outside air instead of recirculating the
higher temperature indoor air. Also, the air handling units can bring in colder night time air
during unoccupied times to cool the entire building mass before occupants enter the building.
A.4.3 Ventilation
As explained in section 4.2, the boiler room exhaust fan and relief vent should be reinstalled to
blow air outwards.
A.4.4 Air Changes and Air Tightening
The building currently receives more outside air than occupancy requires. It is recommended
that and that the fresh air flow is reevaluated based on current occupancy loads and new
ASHRAE standards of 15 CFM per person, and the existing system be rebalanced. This can be
accomplished by incorporating a variable frequency drive into the existing AHU’s to control the
speed at which the motor runs and the air that is pushed through the air handler. The table
below estimates the savings of reducing fresh air to 15 CFM per occupant by rebalancing.
Rank Recommendation
8
Replace AHU-1 motor with premium eff motor, Replace Grundfos 50-80 with Grundfos magna or
equivalent, remove Grundfos 15-58 and replace with ESBE thermic valve, Replace boilers with a multi
pass boiler
Installation Cost $56,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $6,107
Breakeven Cost $110,161 Savings-to-Investment Ratio 2.0 Simple Payback yrs 9
Rank Recommendation
n/a Replace AHU-1 motor with premium eff motor, Replace Grundfos 50-80 with Grundfos magna or
equivalent, remove Grundfos 15-58 and replace with ESBE thermic valve
Installation Cost $6,000 Estimated Life of Measure (yrs) 20 Energy Savings (/yr) $1,698
Breakeven Cost $25,358 Savings-to-Investment Ratio 4.2 Simple Payback yrs 4
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Air sealing is recommended to save 5% or more of building air leakage. This can be done by replacing old
weather stripping, spraying foam round leaky windows, etc.
Rank Recommendation
4 Reduce fresh air into the building (reduce fresh air to 15 CFM per occupant), Reduce time on for
exhaust fans in bathrooms, Reduce on time for boiler room fan by installing room thermostat
Installation Cost $8,000 Estimated Life of Measure (yrs) 15 Energy Savings (/yr) $5,392
Breakeven Cost $75,041 Savings-to-Investment Ratio 9.4 Simple Payback yrs 1
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Appendix B Energy Efficiency Measures that are NOT Recommended
As indicated in other sections of the report, a number of potential EEMs were identified that
were determined to be NOT cost effective by the AkWarm model. These EEMs are not
currently recommended on the basis of energy savings alone because each may only save a
small amount of energy, have a high capital cost, or be expensive to install. While each of
these EEMs is not cost effective at this time, future changes in building use such as longer
operating hours, higher energy prices, new fixtures or hardware on the market, and decreases
in installation effort may make any of these EEMs cost effective in the future. These potential
EEMs should be reviewed periodically to identify any changes to these factors that would
warrant re-evaluation.
Although these upgrades are not currently cost effective on an energy cost basis, the fixtures,
hardware, controls, or operational changes described these EEMs should be considered when
replacing an existing fixture or unit for other reasons. For example, replacing an existing
window with a triple-pane window may not be cost effective based only on energy use, but the if
a window is going to be replaced for some other reason, then the basis for a decision is only the
incremental cost of upgrading from a less efficient replacement window to a more efficient
replacement window. That incremental cost difference will have a significantly shorter payback,
especially since the installation costs are likely to be the same for both units.
The following measures were not found to be cost-effective:
Rank
Feature/Location
Improvement
Description
Annual
Energy
Savings
Installed
Cost
Savings to
Investment
Ratio, SIR
Simple
Payback
(Years)
10 Ceiling w/ Attic:
House
Add R-12 blown cellulose
insulation to attic with
Standard Truss.
$453 $15,993 0.74 35
11 Window/Skylight: Dbl
Wood >3/8 South
Remove existing glass and
install triple, 2 low-E, argon
glass.
$105 $3,780 0.52 36
12 Above-Grade Wall:
Above Grade Wall
Install R-30 rigid foam board
to exterior and cover with T1-
11 siding or equivalent.
$983 $58,878 0.44 60
13
Lighting: Rooms 102,
104, 120, 121, 124,
128, 200, 201, 202,
203, Boiler Shed
Replace with 28 LED (2) 17W
Module StdElectronic $81 $4,600 0.22 57
14
Lighting: Rooms 101,
105, 106, 108, 109,
114, 115
Replace with 14 LED (2) 17W
Module StdElectronic $40 $2,500 0.21 82
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Appendix C Significant Equipment List
HVAC Equipment
Equipment Manufacturer Model No.
Fuel
Type
Estimated
Efficiency Notes
Boiler 1 Weil McLain Model 480 #1 Oil 82% Input Rating 344,000
BTU/hr
Boiler 2 Weil McLain Model 480 #1 Oil 82% Input Rating 344,000
BTU/hr
Distribution Pump- CP-1 Grundfos UPS 50-
80/2F Electric n/a 3/4 HP, 20-150gpm
Distribution Pump- CP-2 Grundfos UPS 50-
80/2F Electric n/a 3/4 HP, 20-150gpm
Domestic Hot Water Circ.
Pump – CP-3 Grundfos UP-15-42B7 Electric n/a 0-17 gpm
Domestic Hot Water Circ.
Pump – CP-4 Grundfos UPS-15-
58FC Electric n/a 1/25 HP, 0-17 gpm
Domestic Hot Water Circ.
Pump – CP-5 Grundfos UPS-15-
58FC Electric n/a 1/25 HP, 0-17 gpm
Air Handling Unit 1 Motor Baldor
Industrial L1318T Electric 67% 1 HP, 1725 RPM
Air Handling Unit 2 Motor Baldor
Industrial L1319T Electric 68% 1 1/2 HP, 1725 RPM
Air Handling Unit 3 Motor Baldor
Industrial L1318T Electric 67% 1 HP, 1725 RPM
Lighting
Location Type Quantity KWH/YR Cost/YR
Rooms 107, 110, 111, 112, 113, 116, 117,
118, 119, 128, 126, 127, Kitchen Hallway Fluor (3) T8 4' 32W Std 133 36015 $ 23,410
Rooms 112, 113 Fluor (3) T5 45.2" F54W/T5 HO 10 3206 2,084
Exterior Lights HPS 100 Watt StdElectronic 5 2334 1,517
Room 101 Fluor (6) T5 45.2" F54W/T5 HO 12 853 554
Rooms 101, 102, 104, 105, 106, 108, 109,
114, 115, 120, 121, 122, 123, 124, 128, 200,
201, 20, 203, Boiler Shed
Fluor (2) T8 4' 32W Std 48 821 534
Power Consumption calculated by AkWarm based on Wattage, schedule and a $0.65 per KWH electric rate.
Plug Loads
Equipment Type Quantity KWH/YR Cost/YR
Refrigerators/Freezers 5 6,000 $ 3,900
Computer Towers 9 1,300 845
Laptops 26 3,400 2,200
Power Consumption calculated by AkWarm based on Wattage, schedule and a $0.65 per KWH electric rate.
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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.
Mentasta Lake 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 75,000 kilowatts (KW) of demand per billing cycle
A-2 – A-5 Services Services 75,000 KW and higher of demand 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.
For our example of the average residential bill, the Utility Charge is calculated:
700 x $.08791 = $61.537
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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 Methods
Analysis Methodology
Data collected was processed using AkWarm energy use software to estimate current energy
consumption by end usage and calculate energy savings for each of the proposed energy
efficiency measures (EEMs). In addition, separate analysis may have been conducted to
evaluate EEMs that AkWarm cannot effectively model to evaluate potential reductions in annual
energy consumption. Analyses were conducted under the direct supervision of a Certified
Energy Auditor, Certified Energy Manager, or a Professional Engineer.
EEMs are evaluated based on building use, maintenance and processes, local climate
conditions, building construction type, function, operational schedule and existing conditions.
Energy savings are calculated based on industry standard methods and engineering
estimations. Each model created in AkWarm is carefully compared to existing utility usage
obtained from utility bills. The AkWarm analysis provides a number of tools for assessing the
cost effectiveness of various improvement options. The primary assessment value used in this
audit report is the Savings/Investment Ratio (SIR). The SIR is a method of cost analysis that
compares the total cost savings through reduced energy consumption to the total cost of a
project over its assumed lifespan, including both the construction cost and ongoing maintenance
and operating costs. Other measurement methods include Simple Payback, which is defined as
the length of time it takes for the savings to equal the total installed cost and Breakeven Cost,
which is defined as the highest cost that would yield a Savings/Investment Ratio of one.
EEMs are recommended by AkWarm in order of cost-effectiveness. AkWarm first calculates
individual SIRs for each EEM, and then ranks the EEMs by SIR, with higher SIRs at the top of
the list. An individual EEM must have a SIR greater than or equal to one in order to be
recommended by AkWarm. Next AkWarm modifies the building model to include the installation
of the first EEM and then re-simulates the energy use. Then the remaining EEMs are re-
evaluated and ranked again. AkWarm goes through this iterative process until all suggested
EEMs have been evaluated.
Under this iterative review process, the savings for each recommended EEM is calculated
based on the implementation of the other, more cost effective EEMs first. Therefore, the
implementation of one EEM affects the savings of other EEMs that are recommended later.
The savings from any one individual EEM may be relatively higher if the individual EEM is
implemented without the other recommended EEMs. For example, implementing a reduced
operating schedule for inefficient lighting may result in relatively higher savings than
implementing the same reduced operating schedule for newly installed lighting that is more
efficient. If multiple EEMs are recommended, AkWarm calculates a combined savings.
Inclusion of recommendations for energy savings outside the capability of AkWarm will impact
the actual savings from the AkWarm projections. This will almost certainly result in lower
energy savings and monetary savings from AkWarm recommendations. The reality is that only
so much energy is consumed in a building. Energy savings from one EEM reduces the amount
of energy that can be saved from additional EEMs. For example, installation of a lower wattage
light bulb does not save energy or money if the bulb is never turned on because of a schedule
or operational change at the facility.
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Appendix F Audit Limitations
The results of this audit are dependent on the input data provided and can only act as an
approximation. In some instances, several EEMs or installation methods may achieve the
identified potential savings. Actual savings will depend on the EEM selected, the price of
energy, and the final installation and implementation methodology. Competent tradesmen and
professional engineers may be required to design, install, or otherwise implement some of the
recommended EEMs. This document is an energy use audit report and is not intended as a
final design document, operation, and maintenance manual, or to take the place of any
document provided by a manufacturer or installer of any device described in this report.
Cost savings are calculated based on estimated initial costs for each EEM. Estimated costs
include labor and equipment for the full up-front investment required to implement the EEM.
The listed installation costs within the report are conceptual budgetary estimates and should not
be used as design estimates. The estimated costs are derived from Means Cost Data, industry
publications, local contractors and equipment suppliers, and the professional judgment of the
CEA writing the report and based on the conditions at the time of the audit.
Cost and energy savings are approximations and are not guaranteed.
Additional significant energy savings can usually be found with more detailed auditing
techniques that include actual measurements of electrical use, temperatures in the building and
HVAC ductwork, intake and exhaust temperatures, motor runtime and scheduling, and infrared,
air leakage to name just a few. Implementation of these techniques is the difference between a
Level III Energy Audit and the Level II Audit that has been conducted.
Disclaimer: "This report was prepared as an account of work sponsored by an agency of the
United States Government. Neither the United States Government nor any agency thereof, nor
any of their employees, makes any warranty, express or implied, or assumes any legal liability
or responsibility for the accuracy, completeness, or usefulness of any information, apparatus,
product, or process disclosed, or represents that its use would not infringe privately owned
rights. Reference herein to any specific commercial product, process, or service by trade name,
trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,
recommendation, or favoring by the United States Government or any agency thereof. The
views and opinions of authors expressed herein do not necessarily state or reflect those of the
United States Government or any agency thereof."
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Appendix G References
Although not all documents listed below are specifically referenced in this report, each contains
information and insights considered valuable to most buildings.
Alaska Department of Education and Early Development; Education Support Services/Facilities.
(1999). Alaska School Facilities Preventative Maintenance Handbook. Juneau, AK:
Alaska Department of Education and Early Development.
Alaska Housing Finance Corportation. (2010). Retrofit Energy Assessment for Loans. AHFC.
ASHRAE. (1997). 1997 ASHRAE Handbook: Fundamentals. Atlanta, GA: ASHRAE.
ASHRAE. (2007). ASHRAE Standard 105-2007 Expressing and Comparing Building Energy
Performance. Retrieved from ASHRAE: www.ashrae.org
ASHRAE. (2007). ASHRAE Standard 90.1-2007 Energy Standards for buildings Except Low-
Rise Residential Buildings. Retrieved from ASHRAE: www.ashrae.org
ASHRAE. (2010). ASHRAE Standard 62.1-2010 Ventilaton for Acceptable Indoor Air Quality.
Retrieved from ASHRAE: www.ashrae.org
ASHRAE. (2010). ASHRAE Standard 62.2-2010 Ventilation and Acceptable Indoor Air Quality in
Low Rise Residential Buildings. Retrieved from ASHRAE: www.ashrae.org
ASHRAE RP-669 and SP-56. (2004). Procedures for Commercial Building Energy Audits.
Atlanta, GA: ASHRAE.
Coad, W. J. (1982). Energy Engineering and Management for Building Systems. Scarborough,
Ontario, Canada: Van Nostrand Reinhold Company.
Daley, D. T. (2008). The Little Black Book of Reliability Management. New York, NY: Industrial
Press, Inc.
Federal Energy Management Program. (2004, March 3). Demand Controlled Ventilation Using
CO2 Sensors. Retrieved 2011, from US DOE Energy Efficiency and Renewable Energy:
http://www.eere.energy.gov/femp/pdfs/fta_co2.pdf
Federal Energy Management Program. (2006, April 26). Low-Energy Building Design
Guidelines. Retrieved 2011, from Department of Energy; Federal Energy Management
Program: http://www.eren.doe.gov/femp/
Institute, E. a. (2004). Variable Speed Pumping: A Guide to Successful Applications. Oxford,
UK: Elsevier Advanced Technology.
International Code Council. (2009). International Energy Efficiency 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 C. This study acquired actual utility data for municipal buildings and schools in
Alaska for the two recent full years. The utility data included costs and quantities including fuel
oil, electricity, propane, wood, steam, and all other energy source usage. This resulted in a
database of approximately 900 buildings. During the course of the benchmarking study, the
comparisons made to the CBECS data appeared to be inappropriate for various reasons.
Therefore, this energy use audit report references the average energy use and energy cost of
Anchorage and Fairbanks buildings as described below.
The Alaska benchmarking data was evaluated in order to find valid comparison data. Buildings
with major energy use information missing were eliminated from the data pool. After detailed
scrutiny of the data, the most complete information was provided to NORTECH by the
Fairbanks North Star Borough School District (FNSBSD) and the Anchorage School District
(ASD). The data sets from these two sources included both the actual educational facilities as
well as the district administrative buildings and these are grouped together in this report as
Fairbanks and Anchorage schools. These two sources of information, being the most complete
and reasonable in-state information, have been used to identify an average annual energy
usage for Fairbanks and for Anchorage in order to provide a comparison for other facilities in
Alaska.
Several factors may limit the comparison of a specific facility to these regional indicators. In
Fairbanks, the FNSBSD generally uses number two fuel oil for heating needs and electricity is
provided by Golden Valley Electric Association (GVEA). GVEA produces electricity from a coal
fired generation plant with additional oil generation upon demand. A few of the FNSBSD
buildings in this selection utilize district steam and hot water. The FNSBSD has recently (the
last ten years) invested significantly in envelope and other efficiency upgrades to reduce their
operating costs. Therefore a reader should be aware that this selection of Fairbanks buildings
has energy use at or below average for the entire Alaska benchmarking database.
Heating in Anchorage is through natural gas from the nearby natural gas fields. Electricity is
also provided using natural gas. As the source is nearby and the infrastructure for delivery is in
place, energy costs are relatively low in the area. As a result, the ASD buildings have lower
energy costs, but higher energy use, than the average for the entire benchmarking database.
These special circumstances should be considered when comparing the typical annual energy
use for particular buildings.
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Appendix I Typical Energy Use and Cost – Continental U.S.
This report references the Commercial Buildings Energy Consumption Survey (CBECS),
published by the U.S. Energy Information Administration in 2006. Initially this report was
expected to compare the annual energy consumption of the building to average national energy
usage as documented below. However, a direct comparison between one specific building and
the groups of buildings outlined below yielded confusing results. Instead, this report uses a
comparative analysis on Fairbanks and Anchorage data as described in Appendix F. An
abbreviated excerpt from CBECS on commercial buildings in the Continental U.S. is below.
Released: Dec 2006
Next CBECS will be conducted in 2007
Table C3. Consumption and Gross Energy Intensity for Sum of Major Fuels for Non-Mall Buildings, 2003
All Buildings* Sum of Major Fuel Consumption
Number of
Buildings
(thousand)
Floor space
(million
square feet)
Floor space
per Building
(thousand
square feet)
Total
(trillion
BTU)
per
Building
(million
BTU)
per
Square
Foot
(thousand
BTU)
per
Worker
(million
BTU)
All Buildings* 4,645 64,783 13.9 5,820 1,253 89.8 79.9
Building Floor space (Square Feet)
1,001 to 5,000 2,552 6,789 2.7 672 263 98.9 67.6
5,001 to 10,000 889 6,585 7.4 516 580 78.3 68.7
10,001 to 25,000 738 11,535 15.6 776 1,052 67.3 72.0
25,001 to 50,000 241 8,668 35.9 673 2,790 77.6 75.8
50,001 to 100,000 129 9,057 70.4 759 5,901 83.8 90.0
100,001 to 200,000 65 9,064 138.8 934 14,300 103.0 80.3
200,001 to 500,000 25 7,176 289.0 725 29,189 101.0 105.3
Over 500,000 7 5,908 896.1 766 116,216 129.7 87.6
Principal Building Activity
Education 386 9,874 25.6 820 2,125 83.1 65.7
Food Sales 226 1,255 5.6 251 1,110 199.7 175.2
Food Service 297 1,654 5.6 427 1,436 258.3 136.5
Health Care 129 3,163 24.6 594 4,612 187.7 94.0
Inpatient 8 1,905 241.4 475 60,152 249.2 127.7
Outpatient 121 1,258 10.4 119 985 94.6 45.8
Lodging 142 5,096 35.8 510 3,578 100.0 207.5
Retail (Other Than Mall) 443 4,317 9.7 319 720 73.9 92.1
Office 824 12,208 14.8 1,134 1,376 92.9 40.3
Public Assembly 277 3,939 14.2 370 1,338 93.9 154.5
Public Order and Safety 71 1,090 15.5 126 1,791 115.8 93.7
Religious Worship 370 3,754 10.1 163 440 43.5 95.6
Service 622 4,050 6.5 312 501 77.0 85.0
Warehouse and Storage 597 10,078 16.9 456 764 45.2 104.3
Other 79 1,738 21.9 286 3,600 164.4 157.1
Vacant 182 2,567 14.1 54 294 20.9 832.1
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Appendix J List of Conversion Factors and Energy Units
1 British Thermal Unit is the energy required to raise one pound of water one degree F°
1 Watt is approximately 3.412 BTU/hr.
1 horsepower is approximately 2,544 BTU/hr.
1 horsepower is approximately 746 Watts
1 "ton of cooling” is approximately 12,000 BTU/hr., the amount of power required
to melt one short ton of ice in 24 hours
1 Therm = 100,000 BTU
1 KBTU = 1,000 BTU
1 KWH = 3413 BTU
1 KW = 3413 BTU/Hr.
1 Boiler HP = 33,400 BTU/Hr.
1 Pound Steam = approximately 1000 BTU
1 CCF of natural gas = approximately 1 Therm
1 inch H2O = 250 Pascal (Pa) = 0.443 pounds/square inch (psi)
1 atmosphere (atm) = 10,1000 Pascal (Pa)
BTU British Thermal Unit
CCF 100 Cubic Feet
CFM Cubic Feet per Minute
GPM Gallons per minute
HP Horsepower
Hz Hertz
kg Kilogram (1,000 grams)
kV Kilovolt (1,000 volts)
kVA Kilovolt-Amp
kVAR Kilovolt-Amp Reactive
KW Kilowatt (1,000 watts)
KWH Kilowatt Hour
V Volt
W Watt
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Appendix K List of Acronyms, Abbreviations, and Definitions
ACH Air Changes per Hour
AFUE Annual Fuel Utilization Efficiency
Air Economizer A duct, damper, and automatic control system that
allows a cooling system to supply outside air to reduce
or eliminate the need for mechanical cooling.
Ambient Temperature Average temperature of the surrounding air
Ballast A device used with an electric discharge lamp to cause
the lamp to start and operate under the proper circuit
conditions of voltage, current, electrode heat, etc.
CO2 Carbon Dioxide
CUI Cost Utilization Index
CDD Cooling Degree Days
DDC Direct Digital Control
EEM Energy Efficiency Measure
EER Energy Efficient Ratio
EUI Energy Utilization Index
FLUOR Fluorescent
Grade The finished ground level adjoining a building at the
exterior walls
HDD Heating Degree Days
HVAC Heating, Ventilation, and Air-Conditioning
INCAN Incandescent
NPV Net Present Value
R-value Thermal resistance measured in BTU/Hr.-SF-̊F (Higher
value means better insulation)
SCFM Standard Cubic Feet per Minute
Savings to Investment Ratio (SIR) Savings over the life of the EEM divided by Investment
capital cost. Savings includes the total discounted dollar
savings considered over the life of the improvement.
Investment in the SIR calculation includes the labor and
materials required to install the measure.
Set Point Target temperature that a control system operates the
heating and cooling system
Simple payback A cost analysis method whereby the investment cost of
an EEM is divided by the first year’s savings of the EEM
to give the number of years required to recover the cost
of the investment.
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Appendix L Building Floor Plan
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As-Built 2nd Floor Plan by NORTECH, Inc.
As-Built Boiler Shed Plan by NORTECH, Inc.