HomeMy WebLinkAboutFAI FNSB Two Rivers School 2012-EEManaging Office
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Fairbanks, Alaska 99709 Anchorage, Alaska 99517 Juneau, Alaska 99801
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ENERGY AUDIT – FINAL REPORT
TWO RIVERS SCHOOL
400 Two Rivers Road
Fairbanks, AK 99712
Prepared for:
Mr. Larry Morris
Fairbanks North Star Borough School District
Prepared by:
David C. Lanning PE, CEA
Douglas Dusek CEA
Stephanie Young EIT, CEAIT
Steven Billa EIT, CEAIT
July 18, 2012
Acknowledgment: "This material is based upon work supported by the Department of
Energy under Award Number DE-EE0000095.”
ENVIRONMENTAL ENGINEERING, HEALTH & SAFETY
Anch: 3105 Lakeshore Dr. Ste 106A, 99517 907.222.2445 Fax: 222.0915
Fairbanks: 2400 College Road, 99709 907.452.5688 Fax: 452.5694
Juneau: 4402 Thane Road, 99801 907.586.6813 Fax: 586.6819
info@nortechengr.com www.nortechengr.com
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY .................................................................................................. 1
2.0 INTRODUCTION ............................................................................................................... 3
2.1 Building Use .......................................................................................................... 3
2.2 Building Occupancy and Schedules ...................................................................... 3
2.3 Building Description ............................................................................................... 3
3.0 BENCHMARKING 2010 UTILITY DATA .......................................................................... 5
3.1 Total Energy Use and Cost of 2010 ...................................................................... 6
3.2 Energy Utilization Index of 2010 ............................................................................ 7
3.3 Cost Utilization Index of 2010 ................................................................................ 8
3.4 Seasonal Energy Use Patterns ............................................................................. 9
3.5 Future Energy Monitoring .................................................................................... 10
4.0 MODELING ENERGY CONSUMPTION ......................................................................... 11
4.1 Understanding How AkWarm Models Energy Consumption ............................... 12
4.2 AkWarm Calculated Savings for the Two Rivers School ..................................... 13
4.3 Additional Modeling Methods .............................................................................. 14
5.0 BUILDING OPERATION AND MAINTENANCE (O & M) .............................................. 15
5.1 Operations and Maintenance .............................................................................. 15
5.2 Commissioning .................................................................................................... 15
5.3 Building Specific Recommendations ................................................................... 15
6.0 CARBON DIOXIDE MONITORING ................................................................................ 16
6.1 Data Analysis ...................................................................................................... 16
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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APPENDICES
Appendix A Recommended Energy Efficiency Measures ........................................... 18
Appendix B Energy Efficiency Measures that are NOT Recommended ..................... 21
Appendix C Significant Equipment List ....................................................................... 22
Appendix D Local Utility Rate Structure ...................................................................... 23
Appendix E Analysis Methodology .............................................................................. 25
Appendix F Audit Limitations ...................................................................................... 26
Appendix G References .............................................................................................. 27
Appendix H Typical Energy Use and Cost – Fairbanks and Anchorage ..................... 28
Appendix I Typical Energy Use and Cost – Continental U.S. .................................... 29
Appendix J List of Conversion Factors and Energy Units .......................................... 30
Appendix K List of Acronyms, Abbreviations, and Definitions .................................... 31
Appendix L Building Floor Plan .................................................................................. 32
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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1.0 EXECUTIVE SUMMARY
NORTECH has completed an ASHRAE Level II Energy Audit of the Two Rivers School, a
26,475 square foot facility in the Fairbanks North Star Borough School District. The audit began
with benchmarking which resulted in a calculation of the energy consumption per square foot. A
site inspection was completed on September 11, 2012 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 recommended EEMs for the Two Rivers School are summarized in the table below.
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 Lighting: Exterior
Lights
Replace with 13 LED 25W
Module StdElectronic $1,080 $9,000 1.6 8.3
2 Lighting: Exterior
Lights
Replace with 9 LED 20W
Module StdElectronic $779 $7,000 1.4 9.0
3 HVAC And DHW
Replace hot water maker with
an indirect water heater, install
alternate summer source of
hot water, add vent dampers to
the boilers
$1,990 $25,000 1.4 13
TOTAL, cost-effective measures $3,849 $41,000 1.4 11
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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Modeled Building Energy Cost Breakdown
The above charts are a graphical representation of the modeled energy usage for the Two
Rivers School. The greatest portion of energy cost for the building is lighting, followed by
envelope air losses and other electrical. Detailed improvements can be found in Appendix A.
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 above on the left hand pie graph and the projected energy
costs, assuming use of the recommended EEMs, are shown on the right.
The chart breaks down energy usage by cost into the following categories:
Envelope Air Losses—the cost to provide heated fresh air to occupants, air leakage, heat lost in
air through the chimneys and exhaust fans, heat lost to wind and other similar losses.
Envelope
o Ceiling—quantified heat loss transferred through the ceiling portion of the envelope.
o Window—quantified heat loss through the window portion of the envelope.
o Wall/Door—quantified heat loss through the wall and door portions of the envelope.
o Floor—quantified heat loss through the floor portion of the envelope.
Water Heating—energy cost to provide domestic hot water.
Fans—energy cost to run ventilation, and exhaust fans.
Lighting—energy cost to light the building.
Refrigeration—energy costs to provide refrigerated goods for the occupants.
Other Electrical—includes energy costs not listed above including cooking loads, laundry loads,
other plug loads and electronics.
Envelope
Air Losses
$8,192
18%
Ceiling
$2,407
5%
Window
$922
2%
Wall/Door
$2,560
6%Floor
$4,403
10%
Water
Heating
$3,548
8%
Lighting
$11,387
26%
Refriger-
ation
$4,560
10%
Other
Electrical
$6,714
15%
Existing Building Energy Cost
$44,693
Envelope
Air Losses
$8,055
18%
Ceiling
$2,301
5%
Window
$785
2%
Wall/Door
$2,406
5%
Floor
$4,341
10%Water
Heating
$2,153
5%
Lighting
$9,529
21%
Refriger-
ation
$4,560
10%
Other
Electrical
$6,713
15%
EEM
Savings
$3,849
9%
Retrofit Building Energy Cost
$40,843
Energy Audit – Final Report
Two Rivers School
Fairbanks, 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 Use
Two Rivers School serves as the elementary education facility for the Two Rivers area near
Fairbanks, Alaska.
2.2 Building Occupancy and Schedules
The building is occupied from 7:30 am to 4:30 pm, Monday through Friday, during the school
year from September to mid-May. Occasionally faculty and staff utilize the building after hours.
Approximately 90 students attend the school with about 20 faculty and support staff.
2.3 Building Description
The school is a two-story, wood framed building, with the lower story partially below ground. The
school has an on-grade slab foundation.
Building Envelope
Building Envelope: Walls
Wall Type Description Insulation Notes
Above-grade walls Wood-framed with 2x8 studs
spaced 16-inches on center. R-25 fiberglass batt. ---
Below-grade walls 8” concrete blocks (CMU) with a
strapped stud wall
Exterior layer of 2inch
Expanded Polystyrene
(EPS).
Along north wall
Building Envelope: Floors
Floor Type Description Insulation Notes
Main Floor Concrete slab 4-inches of expanded
polystyrene along edge ---
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Fairbanks, Alaska
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Heating and Ventilation Systems
Heat is provided to the building by two oil-fired boilers and distributed through three Air Handling
Units (AHUs), a baseboard system and some unit heaters.
Baseboard heat is controlled by pneumatic thermostats with a single setpoint. Ventilation is
demand controlled with CO2 sensors and a small Infinity Direct Digital Control (DDC) system.
Air Conditioning System
No cooling system is installed in the building however economizer cooling using the AHUs is
provided during the spring and fall.
Energy Management
The demand based ventilation, DDC and economizer cooling are the main energy management
systems in the building. The DDC system is available on and off-site to FNSBSD maintenance
staff.
Lighting Systems
Lighting in the building consists of mainly fluorescent, ceiling-mounted fixtures with T8 (1-inch
diameter, four foot) bulbs. Lighting in the gym and library is high-bay fixtures with T5 (5/8-inch
diameter, four foot) bulbs. Occupancy sensors control lighting in the bathrooms and some
offices.
Domestic Hot Water
Domestic hot water is provided by an oil-fired hot water heater. Hot water is not recirculated.
Building Envelope: Roof
Roof Type Description Insulation Notes
All Roofs Hot roof with wood framed
trusses
18- inches fiberglass
batt insulation R-50 ---
Building Envelope: Doors and Windows
Door and Window
Type Description Estimated
R-Value Notes
All Doors Metal doors with insulated cores
(some with double-paned glass) 2.2 ---
Windows Triple-paned, vinyl-framed 3.0 ---
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Two Rivers School
Fairbanks, Alaska
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3.0 BENCHMARKING 2010 UTILITY DATA
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.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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3.1 Total Energy Use and Cost of 2010
The energy use profiles below show the energy and cost breakdowns for the Two Rivers
School. The total 2010 energy use for the building was 1,617 mmBTU and the total cost was
$47,933. These charts show the portion of use for a fuel type and the portion of its cost.
The above charts indicate that the highest portion of energy use is for fuel oil and the highest
portion of cost is for electricity. Fuel oil consumption correlates directly to space heating and
domestic hot water while electrical use can correlate to lighting systems, plug loads, and HVAC
equipment. The energy type with the highest cost often provides the most opportunity for
savings.
Electric
475
29%
Oil
1,142
71%
Energy Use Total
(mmBTU)
Electric
$25,906
54%Oil
$22,027
46%
Energy Cost Total ($)
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Two Rivers School
Fairbanks, Alaska
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3.2 Energy Utilization Index of 2010
The primary benchmarking statistic is the Energy Utilization Index (EUI). The EUI is calculated
from the utility bills and provides a 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 Two Rivers School has an EUI of 61,100 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 Two Rivers School relative to these values. These findings are discussed further in
Appendix H.
61,100 62,000
123,000
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
Btu/ Sq. FtAnnual Energy Use Index (Total Energy/ SF)
Two Rivers Elementary Fairbanks Schools Anchorage Schools
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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3.3 Cost Utilization Index of 2010
Another useful benchmarking statistic 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 Two Rivers School is about $1.81 per square foot per year. This is based on utility
costs from 2010 and the following rates:
Electricity at $ 0.19 / kWh ($ 5.57 / Therm)
# 2 Fuel Oil at $ 2.75 / gallon ($ 1.96 / 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 Two Rivers School relative to these values. More details are
included in Appendix H.
$1.81
$2.42
$2.11
$0.00
$0.50
$1.00
$1.50
$2.00
$2.50
$3.00
$/Sq. FtAnnual Energy Cost Index (Total Cost/ SF)
Two Rivers Elementary Fairbanks Schools Anchorage Schools
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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3.4 Seasonal Energy Use Patterns
Energy consumption is often highly correlated with seasonal climate and usage variations. The
graphs below show the electric and fuel consumption of this building over the course of two
years. The lowest monthly use is called the baseline use. The electric baseline often reflects
year round lighting consumption. The clear relation of increased energy usage during periods of
cold weather can be seen in the months with higher usage.
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
Jan-09Mar-09May-09Jul-09Sep-09Nov-09Jan-10Mar-10May-10Jul-10Sep-10Nov-10KWHElectrical Consumption
Two Rivers Elementary
0
500
1,000
1,500
2,000
2,500
3,000
Jan-09Mar-09May-09Jul-09Sep-09Nov-09Jan-10Mar-10May-10Jul-10Sep-10Nov-10GallonsFuel Oil Deliveries
Two Rivers Elementary
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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3.5 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.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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4.0 MODELING ENERGY CONSUMPTION
After benchmarking of a building is complete and the site visit has identified the specific systems
in the building, a number of different methods are available for quantifying the overall energy
consumption and to model the energy use. These range from relatively simple spreadsheets to
commercially available modeling software capable of handling complex building systems.
NORTECH has used several of these programs and uses the worksheets and software that
best matches the complexity of the building and specific energy use that is being evaluated.
Modeling of an energy efficiency measure (EEM) requires an estimate of the current energy
used by the specific feature, the estimated energy use of the proposed EEM and its installed
cost. EEMs can range from a single simple upgrade, such as light bulb type or type of motor, to
reprogramming of the controls on more complex systems. While the need for a major retrofit
can typically be identified by an energy audit, the specific system upgrades often require
collecting additional data and engineering and design efforts that are beyond the scope of the
Level II energy audit.
Based on the field inspection results and discussions with the building owners/operators,
auditors developed potential EEMs for the facility. Common EEMs that could apply to almost
every older building include:
Reduce the envelope heat losses through:
o increased building insulation, and
o better windows and doors
Reduce temperature difference between inside and outside using setback thermostats
Upgrade inefficient:
o lights,
o motors,
o refrigeration units, and
o other appliances
Reduce running time of lights/appliances through:
o motion sensors,
o on/off timers,
o light sensors, and
o other automatic/programmable systems
The objective of the following sections is to describe how the overall energy use of the building
was modeled and the potential for energy savings. The specific EEMs that provide these overall
energy savings are detailed in Appendix A of this report. While the energy savings of an EEM is
unlikely to change significantly over time, the cost savings of an EEM is highly dependent on the
current energy price and can vary significantly over time. An EEM that is not currently
recommended based on price may be more attractive at a later date or with higher energy
prices.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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4.1 Understanding How AkWarm Models Energy Consumption
NORTECH used the AkWarm model for evaluating the overall energy consumption at Two
Rivers 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.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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4.2 AkWarm Calculated Savings for the Two Rivers School
Based on the field inspection results and discussions with the building owners/operators,
auditors developed potential EEMs for the facility. These EEMs are then entered into AkWarm
to determine if the EEM saves energy and is cost effective (i.e. will pay for itself). AkWarm
calculates the energy and money saved by each EEM and calculates the length of time for the
savings in reduced energy consumption to pay for the installation of the EEM. AkWarm makes
recommendations based on the Savings/Investment Ratio (SIR), which is defined as ratio of the
savings generated over the life of the EEM divided by the installed cost. Higher SIR values are
better and any SIR above one is considered acceptable. If the SIR of an EEM is below one, the
energy savings will not pay for the cost of the EEM and the EEM is not recommended.
Preferred EEMs are listed by AkWarm in order of the highest SIR.
A summary of the savings from the recommended EEMs are listed in this table.
Description Space
Heating
Water
Heating Lighting Refrigeration Other
Electrical Cooking Clothes
Drying Total
Existing
Building $18,484 $3,548 $11,387 $4,560 $5,111 $1,558 $45 $44,693
With All
Proposed
Retrofits
$17,888 $2,154 $9,529 $4,560 $5,111 $1,558 $45 $40,843
Savings $597 $1,394 $1,859 $0 $0 $0 $0 $3,849
Savings in these categories represent the overall savings for the building, and reflect any added
cost that might occur because of a retrofit. For example, installing more efficient lights will
increase the heating load and creating or lowering an unoccupied setback temperature will
increase hot water heat losses and cost.
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Fairbanks, Alaska
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4.3 Additional Modeling Methods
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.
Two Rivers School was calibrated within NORTECH standards in AKWarm. Retrofits for the
HVAC system were adequately modeled in AkWarm and did not require additional outside
calculations.
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5.0 BUILDING OPERATION AND MAINTENANCE (O & M)
5.1 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.
5.2 Commissioning
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.
5.3 Building Specific Recommendations
The Two Rivers School is well maintained. Mechanical areas are orderly and all equipment
seems to be in good repair. Some general recommendations for improvements to the FNSBSD
maintenance program will be made in a separate report.
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6.0 CARBON DIOXIDE MONITORING
6.1 Data Analysis
Carbon dioxide concentration in a few areas of school was monitored for one day, April 19,
2012 as a check on whether significant savings could be found by improving the Demand
Controlled Ventilation (DCV).
The chart above shows the CO2 data collected from the gym return air, the classroom return,
the mixed air plenum and one of the classrooms. In addition the outside air damper position was
plotted to illustrate the system response.
In general, the existing DCV provides both adequate ventilation and good energy savings.
However small to moderate savings could be found through a Level III Energy Audit which
would evaluate the ventilation system and make recommendations in the following areas:
Trend reporting for the control for the outside air damper operation, economizer cooling
or ventilation, for better determination of how and when the system should switch
between the two modes
Better calibration of the classroom return air CO2 levels to return duct air CO2 level
Evaluation of the outside air damper response time to CO2 levels
Evaluation of variable frequency controls for ventilation fan motors
0
10
20
30
40
50
60
70
80
90
100
0
200
400
600
800
1000
1200
1400
1600
1800
2000
4:48 AM7:12 AM9:36 AM12:00 PM2:24 PM4:48 PM7:12 PM9:36 PM12:00 AM2:24 AM4:48 AM7:12 AM9:36 AM12:00 PMCO2Two Rivers CO2
Gym Return
Return from
classrooms
mixed air plenum
Classroom
Outside Air
Damper % open
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APPENDICES
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Fairbanks, 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
Reasonable temperature set backs are already in place in the Two Rivers School. The
baseboards are kept at a lower temperature setting and the increase to 70 degrees is provided
by the ventilation. The ventilation fans stop providing heat promptly at the end of school hours.
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 exterior lights are all high pressure sodium bulbs that should be replaced with much lower
energy use LED lights. The current use of outdoor lighting is a large portion of the electric load.
Rank Location Existing Condition Recommendation
2 Exterior Lights 9 HPS 150 Watt StdElectronic with Manual
Switching
Replace with 9 LED 20W
Module StdElectronic
Installation Cost $7,000 Estimated Life of Measure (yr) 17 Energy Savings (/yr) $779
Breakeven Cost $10,083 Savings-to-Investment Ratio 1.4 Simple Payback (yr) 9
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Copies of bills were not provided by FNSBSD, so it is difficult to determine if Two Rivers
Elementary is subject to demand charges, however if demand charges are included these
retrofits will provide additional savings not predicted here.
A.2.2 Other Electrical Loads
The head bolt heaters in the parking lot for the staff and visitors currently are on a temperature
controlled timing device. Ensuring that this device is functioning according to FNSBSD plans will
help save energy and will generate demand savings.
A.3 Building Envelope: Recommendations for change
A.3.1 Exterior Walls
The existing walls are in good condition, adding insulation is not cost-effective.
A.3.2 Foundation and/or Crawlspace
The foundation is already insulated along the edge. Adding insulation is not practical or cost-
effective.
A.3.3 Roofing and Ceiling
The roof is well insulated, and because of the construction type, adding insulation is cost-
prohibitive.
A.3.4 Windows
The existing windows are energy efficient. Modifications to the windows are not cost-effective.
A.3.5 Doors
The existing doors are commercial grade and in good condition. Replacing the doors is not cost-
effective.
Rank Location Existing Condition Recommendation
1 Exterior Lights 13 HPS 150 Watt StdElectronic with
Manual Switching
Replace with 13 LED 25W
Module StdElectronic
Installation Cost $9,000 Estimated Life of Measure (yr) 17 Energy Savings (/yr) $1,080
Breakeven Cost $13,986 Savings-to-Investment Ratio 1.6 Simple Payback (yr) 8
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A.4 Building Heating System / Air Conditioning
A.4.1 Heating and Heat Distribution
The existing hot water heater is oil-fired, which adds idle and stack losses to the system.
Replacing the unit with an indirect hot water maker connected to the boilers will save a
significant amount of energy. To provide hot water for cleaning during the summers when the
boilers are shut down, a small (ten gallon) electric water heater could be installed in one of the
janitor spaces. The boilers should have vent dampers installed to close the stacks whenever the
boiler is not firing. This will reduce idle losses from the boilers.
A.4.2 Air Conditioning
No air conditioning system is installed in the building.
A.4.3 Ventilation
During the audit CO2 monitoring was conducted. The results indicate that some smaller savings
can be achieved through a Level III energy audit of the DCV system.
A.4.4 Air Changes and Air Tightening
The building shell is in good condition. No EEMs are recommended in this area.
Rank Recommendation
3 Replace hot water maker with an indirect water heater, install alternate summer source of hot water,
add vent dampers to the boilers
Installation Cost $25,000 Estimated Life of Measure (yr) 20 Energy Savings (/yr) $1,990
Breakeven Cost $34,715 Savings-to-Investment Ratio 1.4 Simple Payback (yr) 13
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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
Estimated
Annual
Energy
Savings
Estimated
Installed
Cost
Savings to
Investment
Ratio, SIR
Simple
Payback
(Years)
4 Above-Grade
Wall: All Walls
Install R-30 rigid foam board to
exterior and cover with T1-11
siding or equivalent.
$1,258 $73,491 0.40 58
5 Cathedral
Ceiling: House
Install R-5 rigid board
insulation. No cost included for
covering insulation.
$254 $275,619 0.02 1,085
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Appendix C Significant Equipment List
HVAC Equipment
Equipment Manufacturer Model No. Fuel Type Estimated
Efficiency Notes
Boiler Burnham PF 505 #2 Fuel Oil 78% Two Units
Pumps Grundfos UP 65-160E Electric --- Two units
Pumps Grundfos UPS 20-42 Electric --- Secondary Loop
AHU-1 Gould (motor) --- Electric --- Demand
Controlled
AHU-2 Mangnatek (motor) --- Electric --- Demand
Controlled
AHU-3 Mangnatek (motor) --- Electric --- Demand
Controlled
Water Heater Bock 136E #2 Fuel Oil 78% Single Unit
Lighting
Location Lighting Type Bulb Type Quantity KWH/YR Cost/YR
Classrooms Fluorescent T8 84 12521 $ 2379
Exterior Lights High Pressure
Sodium 150W 22 11731 2229
Gym Fluorescent T5 15 4978 946
Offices Fluorescent T8 34 3427 651
Music+Computer Lab Fluorescent T8 32 1296 246
Library Fluorescent T5 4 1269 241
Bathrooms Fluorescent T8 6 894 170
Library Loft Fluorescent T8 6 894 170
Exit Lights LED 4W 12 668 127
Mechanical, Janitor,
Storage Fluorescent T8 60 62 12
Energy Consumption calculated by AkWarm based on wattage, schedule and an electric rate of $ 0.19 kWh
Plug Loads
Equipment Location Manufacturer KWH/YR Cost/YR
Server Server Rooms Varies 13149 $ 2498
Commercial Freezer Kitchen --- 13000 2470
Commercial Refrigerator Kitchen ---- 10000 1900
Head Bolt Heaters Outdoors --- 8205 1559
Computers Classrooms Varies 3898 741
Classroom Equipment Classrooms Varies 1649 313
Mini Refrigerators Classrooms Varies 1000 190
Energy Consumption calculated by AkWarm based on wattage, schedule and an electric rate of $ 0.19 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.
Golden Valley Electrical Association Rate Structure:
GS-2 Large General Service Rate Structure (GVEA)
Rate Component Unit Charge
Customer Charge $30.00
Utility Charge $0.04843 per kWh
Demand Charge $11.06 per KW
Cost of Fuel $0.12527 per kWh
Regulatory Cost Charge (RCC) $0.000492 per kWh
2010 Average Rate
(Two Rivers School) $0.19 per kWh
GVEA offers five different rates to its members, depending on the classification of the service
provided. The rates are divided into two categories: Residential and General Service (GS).
Eighty-five percent of the electric services on GVEA's system are single-family dwellings,
classified under the Residential rate. The four General Service rates apply to small and large
power users that do not qualify for the Residential rate.
The General Service rates break down as follows:
GS-1 General Service Services under 50 kilowatts (kW) of demand per billing cycle
GS-2(S) Large General Service
Secondary Services 50 kW and higher of demand per billing cycle
GS-2(P) Large General Service
Primary Services at primary voltage
GS-3 Industrial Service Services at transmission voltage
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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Fuel and Purchased Power
This charge is based on a combination of forecasted and actual power costs. The monthly
charge allows Golden Valley to pass on increases and decreases in fuel and energy purchases
to our members. It is calculated quarterly and multiplied by the kilowatt-hours used each month.
Demand Charge
GS2 and GS3 rates for business and industry include a demand charge per kilowatt. Demand is
the maximum rate of delivery of electric energy during the month, measured in kilowatts and
registered as the highest average rate of energy used over and fifteen-minute period during the
month.
Copies of bills were not provided by FNSBSD, so it is difficult to determine how large demand
charges are.
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.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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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)
Floorspace
(million
square feet)
Floorspace
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 Floorspace (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.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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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
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 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 = 1000 BTU
1 CCF of natural gas = about 1 Therm
1 Pascal (Pa) = 1 inch H2O = 0.363 pounds/square inch (psi)
1 Pascal (Pa) = 0.0025 atmospheres (atm)
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
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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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.
CO carbon monoxide
CUI Cost Utilization Index
CDD Cooling Degree Days
CMU Concrete Masonry Unit
DDC Direct Digital Control
EEM Energy Efficiency Measure
EER Energy Efficient Ratio
EUI Energy Utilization Index
FLOUR Fluorescent
Grade The finished ground level adjoining a building at the
exterior walls
HDD Heating Degree Days
HVAC Heating Ventilation 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 Reduction of heating or cooling by changing the set point
during hours when the building or space is unoccupied
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.
Energy Audit – Final Report
Two Rivers School
Fairbanks, Alaska
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Appendix L Building Floor Plan
Floor plan provided by Two Rivers School.