HomeMy WebLinkAboutBBNC-A63-CAEC Twin Hills School 2012-EEENERGY AUDIT FINAL REPORT
Twin Hills K-12 School
100 Twin Hills School Lane
Twin Hills, AK 99576
p (907) 842-5280
AkWarm ID No. BBNC-A63-CAEC-01
800 F Street
Anchorage, AK 99501
p (907) 276-6664 f (907) 276-5042
Contact: Walter Heins, PE, CCP, CxA, CEA
32215 Lakefront Dr.
Soldotna, Alaska 99669
p (907) 260-5311
Contact: Jerry P. Herring, PE, CEA
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 i AkWarm No. BBNC-A63-CAEC-01
Contents
I. Executive Summary .................................................................................................................. 1
II. Introduction .............................................................................................................................. 5
III. Energy Audit Process ............................................................................................................. 6
IV. Method of Analysis ................................................................................................................. 7
V. Building Description ................................................................................................................ 8
V.I SCHOOL ARCHITECTURAL DESCRIPTION ................................................................................ 8
V.II MECHANICAL DESCRIPTION .................................................................................................. 8
V.III ELECTRICAL DESCRIPTION .................................................................................................. 9
V.IV OUTBUILDINGS DESCRIPTION .............................................................................................. 9
VI. Historic Energy Consumption and Cost............................................................................. 11
VI.I ELECTRICAL CONSUMPTION DATA ..................................................................................... 11
VI.II FUEL OIL CONSUMPTION DATA ......................................................................................... 11
VI.III OVERALL ENERGY CONSUMPTION DATA ......................................................................... 11
VII. Equipment Inventory and Photo Survey .......................................................................... 13
VIII. Energy Conservation Measures ....................................................................................... 14
VIII.I TWIN HILLS SCHOOL ........................................................................................................ 14
VIII.II PORTABLE BUILDING ...................................................................................................... 18
VIII.III ADMINISTRATIVE CONTROLS FOR ENERGY CONSERVATION AND OPTIMIZATION .......... 20
Appendices
Appendix A – Energy Benchmark Data
Appendix B – AkWarm Commercial Reports
Appendix C – Major Equipment List
Appendix D – Energy Conservation Measures
Appendix E – Site Visit Photos
Appendix F - AkWarm Model of Portable Building
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REPORT DISCLAIMER
Privacy
The information contained within this report, including any attachment(s), was produced under contract to Alaska
Housing Finance Corporation (AHFC). IGAs are the property of the State of Alaska, and may be incorporated into
AkWarm-C, the Alaska Retrofit Information System (ARIS), or other state and/or public information systems.
AkWarm-C is a building energy modeling software developed under contract by AHFC.
Limitations of Study
This energy audit is intended to identify and recommend potential areas of energy savings, estimate the value of the
savings, and provide an opinion of the costs to implement the recommendations. This audit meets the criteria of a
Level 2 Investment Grade Audit (IGA) per the American Society of Heating, Refrigeration, Air-conditioning
Engineers (ASHRAE) and the Association of Energy Engineers (AEE), and is valid for one year. The life of the IGA
may be extended on a case-by-case basis, at the discretion of AHFC. In preparing this report, the preparers acted
with the standard of care prevalent in this region for this type of work. All results are dependent on the quality of
input data provided. Not all data could be verified and no destructive testing or investigations were undertaken.
Some data may have been incomplete.
This report is not intended to be a final design document. Any modifications or changes made to a building to realize
the savings must be designed and implemented by licensed, experienced professionals in their fields. Lighting
upgrades should undergo a thorough lighting analysis to assure that the upgrades will comply with State of Alaska
Statutes as well as Illuminating Engineering Society (IES) recommendations. All liabilities for upgrades, including
but not limited to safety, design, and performance are incumbent upon the professional(s) who prepare the design.
Coffman Engineers, Inc (CEI) and Central Alaska Engineering Company (CAEC) bear no responsibility for work
performed as a result of this report.
Financial ratios may vary from those forecasted due to the uncertainty of the final installed design, configuration,
equipment selected, installation costs, related additional work, or the operating schedules and maintenance provided
by the owner. Furthermore, many ECMs are interactive, so implementation of one ECM may impact the
performance of another ECM. CEI and CAEC accept no liability for financial loss due to ECMs that fail to meet the
forecasted financial ratios.
The economic analyses for the ECMs relating to lighting improvements are based solely on energy savings.
Additional benefits may be realized in reduced maintenance cost, deferred maintenance, and improved lighting
quality. The new generation lighting systems have significantly longer life leading to long term labor savings,
especially in high areas like Gyms and exterior parking lots. Lighting upgrades displace re-lamping costs for any
fixtures whose lamps would otherwise be nearing the end of their lifecycle. This reduces maintenance costs for 3-7
years after the upgrade. An overall improvement in lighting quality, quantified by numerous studies, improves the
performance of students and workers in the built environment. New lighting systems can be designed to address all
of the above benefits.
US Government Disclaimer:
This material is based upon work supported by the Department of Energy under Award Number DE-EE0000095.
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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I. Executive Summary
This report presents the findings of an energy audit conducted at Twin Hills K-12 School as part of a
contract for:
Alaska Housing Finance Corporation
Contact: Rebekah Luhrs
4300 Boniface Parkway
Anchorage, AK 99510
Email: rluhrs@ahfc.us
SW Region School District
Contact: Rick Dallmann
P.O. Box 90
Dillingham, AK 99576
Email: rdallmann@swrsd.org
This audit was performed using American Recovery and Reinvestment Act (ARRA) funds to promote the
use of innovation and technology to solve energy and environmental problems in a way that improves the
State of Alaska’s economy. This can be achieved through the wiser and more efficient use of energy.
The average January 2009-December 2010 documented annual utility costs at this facility are as follows:
Electricity $8,260
Fuel Oil #1 $58,192
Total $66,452
January 2009-December 2010 Energy Utilization Index (EUI) = 232.47 kBTU/sf
January 2009-December 2010 Energy Cost Index = 9.03 $/sf
Energy Conservation Measures (ECMs) calculated to be cost effective are shown below in the Executive
Summary Table with the energy analyst’s best opinion of probable cost, savings, and investment returns.
Be aware that the measures are not additive because of the interrelation of several of the measures. The
cost of each measure for this level of auditing is ± 30% until detailed engineering, specifications, and hard
proposals are obtained. See section VIII for detailed descriptions of all cost effective ECMs.
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Executive Summary – Recommended ECMs
Twin Hills K-12 School (THS)
Rank Feature Recommendation Annual
Energy
Savings
Installed
Cost
SIR Paybac
k
(Years)
THS -0a Refrigerators Replace residential & light
commercial
refrigerators/freezers older
than 5 years old
-- - <10
THS -1 Setback
Thermostat:
Gym
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Gym space.
$1,762 $400 66.09 0.2
THS -2 Setback
Thermostat:
Classroom,
Library,
Hallway
Space
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Classroom, Library,
and Hallway Space.
$4,877 $1,400 52.28 0.3
THS -3 Bathroom
Lighting
Control
Install Occupancy Sensors $840 $400 29.74 0.5
THS -4 Maintenance
Closet
Lighting
Relamp with CFL $46 $10 12.94 0.2
THS -5 Setback
Thermostat:
Storage/Inter
mittent Use
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Storage & Intermittent
Use Spaces.
$339 $400 12.70 1.2
THS -6 Classroom
Lighting
Replace with 2-lamp T8
fluorescent; Add bi-level
switching with motion
controls.
$1,030 $3,150 4.60 3.1
THS -7 Exterior
Lighting
Replace with LED; Add
photo switch controls
$1,670 $6,000 2.66 3.6
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Executive Summary – Recommended ECMs
Twin Hills K-12 School (THS)
Rank Feature Recommendation Annual
Energy
Savings
Installed
Cost
SIR Paybac
k
(Years)
THS -8 Gym
Lighting
Replace with T5HO
fluorescent; Add bi-level
switching with motion
controls.
$1,210 $6,500 2.60 5.4
THS -9 Replace
Exterior
Doors
Remove existing door and
install standard pre-hung
U-0.16 insulated door,
including hardware.
$325 $3,500 2.55 10.8
THS -10 Hallway
Lighting
Replace with ballasts with
high-efficiency electronic;
Add bi-level switching
with motion controls.
$440 $2,600 2.40 5.9
THS -11 Windows Replace existing window
with U-0.28 wood window
$687 $10,100 1.26 15.32
THS -12 Air
Tightening
Perform air sealing to
reduce air leakage by 20%.
$2,373 $22,000 1.11 9.3
Notes:
a Due to advances in refrigerators in the previous 5 years, new Energy Star refrigerators are much more efficient and
result in viable energy savings.
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Portable Building ECMs
All ECMs shown in the Portable Building Executive Summary, below, are based on the AkWarm model
for the teacher housing portable building.
Executive Summary – Recommended Energy Conservation Measures (ECMs)
Portable Building (PB)
Rank Feature Recommendation
Annual
Energy
Savings
Installed
Cost SIR Payback
(years)
PB-1 Setback
Thermostat:
Portable Building
Implement a Heating
Temperature Unoccupied
Setback to 65.0 deg F for
the Portable Building
space.
$343 $400 12.86 1.2
PB-2 Exterior Door:
Portable Building
- Doors
Remove existing door
and install standard pre-
hung U-0.16 insulated
door, including hardware.
$239 $1, 500 4.42 6.1
PB-3 Exposed Floor:
Portable Building
- Floor
Install R-14 rigid board
insulation.
$294 $2,900 2.73 9.9
PB-4 Above-Grade
Wall: Portable
Building - 2x4
Stud Wall
Install R-10 rigid foam
board to exterior and
cover with T1-11 siding
or equivalent to increase
wall insulation to R-21.
$705 $12,200 1.57 17.2
PB-5 Window/Skylight:
Portable Building
- Double Pane
Windows
Replace existing window
with U-0.22 vinyl
window
$359 $6,800 1.03 18.8
PB-6 Air Tightening Perform air sealing to
reduce air leakage by
30%.
$691 $7,000 1.02 10.1
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II. Introduction
This energy audit was conducted at Twin Hills K-12 School (THS) for AHFC and the SW Regional
School District. The 7,360 square foot (sf) campus includes a 6,499 sf school and an 861 sf teacher
housing unit. The school consists of classrooms, restrooms, administrative offices, a library, and a
gymnasium. The location of the school is shown in the following regional and overhead images. The
energy audit was conducted in order to evaluate areas and equipment where energy savings can be
realized. The savings are then compared to a baseline and evaluated for reasonable project financial ratios
and payback.
Twin Hills, Alaska – Google Maps
Twin Hills K-12 School – Google Earth
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III. Energy Audit Process
Prior to visiting the school, the first task was to collect and review two years of utility data for electricity
and fuel oil usage. This information was used to analyze operational characteristics, calculate energy
benchmarks for comparison to industry averages, estimate savings potential and establish a baseline to
monitor the effectiveness of implemented energy conservation measures. A spreadsheet was used to enter,
sum, and calculate benchmarks and to graph energy use information (see Appendix A). The primary
benchmark calculation used for comparison and baseline data is the Energy Utilization Index, or EUI (see
Section VI).
After gathering the utility data and calculating the EUI, the next step in the audit process was to review
the architectural and engineering drawings to develop a building profile which documented building age,
type, usage, and major energy consuming equipment or systems such as lighting, Heating, Ventilating,
and Air Conditioning (HVAC), water heating, refrigeration, snow-melt, and etc. The building profile is
utilized to generate, and answer, all possible questions regarding the facility’s energy usage. These
questions were then compared to the energy usage profiles developed during the utility data gathering
step. After this information was gathered, the next step in the process was the site survey.
A site survey was completed on August 8, 2011. We spent our time inspecting the building systems that
impact energy consumption and answering questions from the preliminary review of the school. The on-
site contact during the investigation was Mr. Rick Dallmann of the Southwest Region School District
(SWRSD)1. The following information was collected while on site: occupancy schedules, O&M practices,
building energy management program, and other information that has an impact on energy consumption.
The following energy audit includes an evaluation of the information gathered, researching of possible
conservation opportunities, organizing the energy audit into a comprehensive report, and making ECM
recommendations for mechanical, electrical, and building envelope improvements.
1 Mr. Rick Dallmann, (907) 842-5280 (office)
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IV. Method of Analysis
Having completed the preliminary energy audit tasks, Coffman Engineers, Inc., (CEI) conducted a site
survey. The site survey provides critical input in deciphering where energy savings opportunities exist
within a facility. The audit team from CEI walked the entire site to inventory and investigate the building
envelope and major equipment, including: HVAC, water heating, lighting, and equipment located in
shops, kitchens, offices, and classrooms. An understanding of how the equipment is used is determined
during the site survey.
The collected data was entered into AkWarm Commercial™ software, an energy calculating program for
buildings. The data was processed by AkWarm to model a baseline from which ECMs could be
considered. The model was compared to actual utility costs to ensure the quality of the baseline and
proposed energy modeling performed by AkWarm. The recommended ECMs focus on the building
envelope, HVAC, lighting, water heating, and other electrical measures that will reduce annual energy
consumption.
ECMs are evaluated based on building use and processes, local climate conditions, building construction
type, function, operational schedule, existing conditions, and foreseen future plans. When new equipment
is proposed, energy consumption is calculated based on the manufacturer’s cataloged information. Energy
savings are calculated by AkWarm.
Implementation of more than one ECM often affects the savings of other ECMs. The savings may in
some cases be relatively higher for an ECM implemented individually than when that ECM is just one of
multiple recommended ECMs. For example, implementing reduced operating schedules of inefficient
lighting systems may result in a given savings. Also implementing a more efficient lighting system will
add to the savings, but less than the efficient lighting would alone because there is less energy to be saved
when the lights are on a reduced operating schedule. Thus, if multiple ECM’s are recommended, the
combined savings are calculated and identified appropriately in groups.
In Appendix D, Energy Conservation Measures, the simple lifetime calculation is shown for each ECM,
which is based on the typical life of the equipment being replaced or altered. The energy savings are
extrapolated throughout the simple lifetime of the ECM. The total energy savings is calculated as the total
lifetime multiplied by the yearly energy savings.
The cost savings and installation costs are used to calculate simple payback2 and the Savings to
Investment Ratio3 (SIR). These are listed in Appendix D and summarized in the Executive Summary
Table of this report. The SIR is calculated as a ratio by dividing the break even cost by the initial installed
cost. Cost savings is calculated based on the historical energy costs for the building. Installation costs
include labor and equipment to evaluate the initial investment required to implement an ECM. These are
applied to each recommendation with simple paybacks calculated. The energy analyst’s opinions of
probable cost are garnered from RS Means Cost Data, other industry publications, and local contractors
and suppliers. In addition, where applicable, maintenance cost savings are estimated and applied to the net
savings.
2 The simple payback is based on the years that it takes for the net savings to payback the net installation cost (Cost
divided by Savings).
3 Savings to Investment Ratio (SIR): Break Even Cost divided by initial installed cost, where Break-Even Cost is
how much can be spent and still have the measure be cost effective; it equals the Present Value (PV) of Savings over
the life of the measure minus PV of maintenance costs.
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V. Building Description
Twin Hills K-12 School is a two story facility with classrooms, offices, a kitchen, library, and a gym.
The school is occupied by 24 people, and is normally operated from 7am-3pm on weekdays from August
through May. The gym operates with slightly extended hours from 8:30am-4pm. During the summer
months, late May through early August, the school is used by the community for a limited number of
hours per week. For modeling purposes, we assumed that the school is occupied an average of five hours
per week during the summer months.
There are three additional buildings on the property. One building provides housing for the teachers and is
occupied 24 hours per day year round while the other two buildings consist of storage and utility areas
with no regular occupancy. A detailed description of each outbuilding can be found in section V.V of this
report.
V.I School Architectural Description
Wall, floor, and roof construction details were obtained from the architectural drawings. The school’s
exterior walls are primarily constructed of 2x6 wood studs on 16” centers with R-19 fiberglass batts,
plywood sheathing, and metal siding for an effective R-value of R-16.7. The exterior walls of the four
foot high crawlspace are also an insulated wood construction but are wrapped with asphalt emulsion
damproofing and two layers of 1.5” R-11 rigid insulation. The rigid insulation extends from the concrete
footers, buried 8’-2” below grade, to within one foot of the finished grade and yields an effective R-value
of R-20. The total exterior wall area for the school is 8,423 sf,
The school has an insulated cold roof with 6” of R-19 fiberglass batt insulation covered by 3.5” of R-13
fiberglass batt insulation, plywood sheathing and metal roof panels. The composite R-value for this roof
assembly is R-33.
The school windows all consist of double paned glass with a ½” air space and wood frames. All of the
windows are operable using crank handles and, upon inspection, it was observed that the seals around the
window are aged beyond their useful life and no longer perform their weather stripping function. The
windows were installed during original construction and are approximately 33 years old. The total
window area for the school building is 158 sf with 30 sf facing south.
The majority of the school’s exterior doors are insulated, hollow metal doors with an R-value of R-1.7.
The building has one solid core, metal door (R-2.2) and one insulated, hollow metal door with a half lite
window (R-2.1). All of the doors were installed during original construction and are now approximately
33 years old.
V.II Mechanical Description
The school is heated by three Burnham PV77WC-TBWN2S fuel oil boilers that were installed
approximately 10 years ago. Each boiler handles approximately 30% of the heating load and has an
output of 213 MBH. They are equipped with Carlin burners rated at 2-3 GPH. The hydronic fluid is 60%
propylene glycol and 40% water. The boilers, located in the utility outbuilding, are typically shut down
during summer break and are restarted in August for the school year. Heat is supplied to the school via
100 ft of buried arctic (pre-insulated) piping.
Ventilation for the school is provided by two forced air furnaces with hydronic heating coils. One furnace,
FUR-1, provides tempered air to the gym area of the school while the other furnace, FUR-2, serves the
classrooms and office spaces. The heating coils are supplied with heat from the boilers to temper the
outside air. The CEI site survey revealed an additional furnace that was installed to provide redundancy
for FUR-1. This furnace has never been used and is isolated from the ventilation system by manually
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operated dampers. The furnaces are turned off during the summer break and are restarted in August for
the school year.
The heating and ventilation systems are controlled using line voltage thermostats. There is no Direct
Digital Control (DDC) management system in the building which would offer vast improvements in
monitoring, control, and operating efficiencies.
Building hot water is provided by an Amtrol 41 gallon indirect water heater, which is heated by a heating
loop from the boiler. Domestic hot water use is estimated at 90 gallons per day, based on occupancy.
V.III Electrical Description
The school is served by a 400 Amp (A), 120/208 Volt (V), 3-phase, 4-wire, overhead service. The service
entrance is at the generator building. A 225A underground feeder from the generator serves the school
building. A 100A feeder from the generator serves the teacher housing building. The there is also a 100A
feeder from generator building that goes to an unknown location. The electric utility is the Twin Hills
Village Council. The school has two standby, reciprocating diesel generators.
Interior lighting for the Twin Hills School is primarily provided by fluorescent light fixtures controlled by
manual wall switches. These light fixtures were originally installed with T12 lamps and magnetic ballasts,
however most have been converted to use T8 lamps with electronic ballasts. The lighting levels in the
classrooms were measured at 100 foot-candles. This is double that level recommended by current
Illumination Engineering Society of North American (IESNA) standards.
The Gym lighting is composed of T12 fluorescent strip fixtures and high wattage incandescent fixtures on
dimmers. The lighting levels in the gym were measured at 20 foot-candles. This is lower the 30-50 foot-
candles recommended by current IESNA standards.
Exterior lighting is provided by high pressure sodium (HPS) wall packs and incandescent fixtures over
entrances. The wall packs were observed to be controlled by an on/off photo switch while the
incandescent fixtures appeared inoperable.
Other electricity-using equipment not previously described in the mechanical or electrical sections include
an upright 22 cubic foot (cf) light-commercial freezer manufactured in1994, an upright 19.7cf light-
commercial freezer manufactured in 2001, a residential chest freezer manufactured in 1992, an upright
light commercial refrigerator (which could be shut down in the summer to save energy), a microwave and
other various kitchen equipment, and various user equipment such as projectors, computers, and printers.
During the CEI site survey, two electrical safety hazards were observed. A circuit breaker panel in the
generator building is missing covers over its spare circuit breaker slots which exposes live bus work.
Additionally, an exterior lighting fixture near the main entrance has exposed conductors. It is outside the
scope of the energy audit to identify and evaluate electrical hazards or provide recommendations for
repair, however these were mentioned in this report in the interest of safety.
V.IV Outbuildings Description
The teacher housing building is constructed of 2x4 studs at 16”O.C. with R-11 fiberglass batt insulation,
plywood sheathing, and metal siding. The building has a crawlspace/utilidor area beneath it that is skirted
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with plywood and insulated with R-11 fiberglass batts. An attic space with fiberglass batt insulation
provides for a cold roof composed of conventional roof trusses. There are six double-paned windows,
with an R-value of R-1.8, and two R-1.7 exterior metal doors. A buried arctic pipe from the school’s
heating water system supplies heat to the baseboard heaters, the 40 gallon indirect hot water heater, and to
the unit heater located in the crawlspace.
The cold storage building is an abandoned double wide trailer that has been disconnected from the
school’s heating system as well as any electrical services.
The utility outbuilding houses the boilers, the heating circulation pumps, and the two backup generators.
It is a 12’x48’ portable unit with the same building construction as the teacher housing unit. The building
is not heated and as such was not included in the energy models.
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VI. Historic Energy Consumption and Cost
Tables provided in Appendix A, Energy Benchmark Data Report, represent the electric and fuel oil
energy usage for the school. Twin Hills Village Council (THVC) provides the electricity and Delta
Western, Inc. provides the fuel oil to the building. Both utility companies bill the school using a
commercial rate schedule.
VI.I Electrical Consumption Data
The electric utility costs consist of several components: a fixed monthly customer charge, an energy usage
charge, fuel surcharge, taxes, and a demand charge. The energy usage and fuel surcharge are based on the
customer's usage as measured in kilowatt-hours (kWh). The usage (kWh) is determined by load wattage
divided by 1,000, times hours running. For example, a 1,000 watt space heater operating for one hour will
use 1 kWh of electricity as would ten, 100 watt lamps operating for one hour or one, 100W lamp
operating for 10 hours. One kWh is equivalent to 3,413 BTU. Utility data used in this report reflects the
historical data provided for the building in a summarized format. The actual utility bills were not provided
to be able to verify the data received to assure 100 percent accuracy of the data.
Upon review of the historical electrical consumption data, anomalies were discovered. Reasonable,
conservative calculations of annual consumption of documented lighting and equipment from the site visit
exceeded the documented consumption data provided to CEI for analysis. The modeled usage was
approximately 250% of the 'actual' usage. This could be explained by faulty metering equipment or
excessive generator usage. Recovering or documenting such lost data is outside of the scope of the energy
audit, therefore the electrical consumption calculations were used as the input data for the electrical
model. However, it may be of interest to the School District to determine the reason for the anomalies.
VI.II Fuel Oil Consumption Data
The fuel oil utility measures consumption and bills in gallons of fuel oil. Oil is delivered and invoiced
once annually. Ideally, the storage tanks are "topped off" but in reality the amount purchased can be
influenced by school district budgets. Correlation to the invoices assumes that the annual expenditure is
equal to one year's usage. The average heat value of fuel oil #1 is 132,000 BTUs per gallon. Fuel oil is
sold to the customer in units of gallons which is equal to approximately 1.32 Therms of energy, or
132,000 Btu’s of heating power.
Upon review of the historic fuel oil consumption data, anomalies were discovered. Reasonable,
conservative calculations of annual consumption of documented mechanical equipment from the site visit
were much less than the documented consumption data provided to CEI for analysis. The modeled usage
was approximately 85% of the ‘actual’ usage. This could be explained by faulty fuel oil metering
equipment or excessive generator usage, resulting in higher amounts of fuel oil being burned. Recovering
or documenting such lost data is outside of the scope of the energy audit, therefore the mechanical
consumption calculations were used as the input data for the energy model. However, it may be of interest
to the School District to determine the reason for the anomalies.
VI.III Overall Energy Consumption Data
The overall cost for energy use is calculated by dividing the total cost by the total usage. Based on the
electric and fuel oil utility data provided, the average cost for the energy and consumption calculations at
the surveyed facility are summarized in the table below. See Appendix A for actual data and averaging
methodology.
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Energy Cost and Consumption Data
2009 2010 Average
Electric $0.55 /kWh $0.55/kWh $0.55 /kWh
#1 Fuel Oil $5.44 /Gal $3.85 /CCF $4.65 /Gal
Total Cost $75,073 $57,832 $66,452
ECI $10.20 /sf $7.86 /sf $9.03 /sf
Electric EUI 6.9 kBTU/sf 7.0 kBTU/sf 6.9 kBTU/sf
#1 Fuel Oil EUI 220.6 kBTU/sf 230.5 kBTU/sf 225.5 kBTU/sf
Building EUI 227.5 kBTU/sf 237.5 kBTU/sf 232.5 kBTU/sf
The Energy Cost Index (ECI) is derived by dividing the annual cost by the building square footage. The
building square footage was calculated to be approximately 7,360 square feet. This area includes the
6,499 sf school and the 861 sf teacher housing unit.
The annual EUI is expressed in Thousands of British Thermal Units per Square Foot (kBTU/sf) and can
be used to compare energy consumption of similar building types or to track consumption from year to
year in the same building. The EUI is calculated by converting annual consumption of all fuels used to
Btu’s and then dividing by the area (gross conditioned square footage) of the building. EUI is a good
indicator of the relative potential for energy savings. A comparatively low EUI indicates less potential for
large energy savings. Building architectural, mechanical, and electrical drawings were obtained and
utilized to calculate and verify the gross area of the facility. The gross area was confirmed on the physical
site investigation.
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VII. Equipment Inventory and Photo Survey
Following the completion of the field survey a detailed equipment list was created and is attached as
Appendix C. The major equipment listed are considered to be the major energy consuming equipment in
the building whose replacement could yield substantial energy savings.
An approximate age was assigned to the equipment if a manufactured date was not shown on the
equipment’s nameplate. As listed in the 2011 ASHRAE Handbook for HVAC Applications, Chapter 37,
Table 4, the service life for the equipment along with the remaining useful life in accordance to the
ASHRAE standard are also noted in the equipment list.
Where there are zero (0) years remaining in the estimated useful life of a piece of equipment, this is an
indication that maintenance costs are likely on the rise and more efficient replacement equipment is
available which will lower the operating costs of the unit. Maintenance costs should also fall with the
replacement.
Additionally, photos of various equipment and the building construction were taken during the site visit.
Several photos are included in Appendix E.
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VIII. Energy Conservation Measures
VIII.I Twin Hills School
ECM# THS-0 – Replace residential & light commercial refrigerators/freezers older than 5 years old
Annual Energy Savings Installed Cost SIR Payback (years)
---<10 years
Due to advances in refrigerators in the previous five years, new Energy Star residential-type and light
commercial-type refrigerators and freezers are much more efficient and result in viable energy savings.
Built-in refrigerators and freezers should be evaluated independently. Replacing existing refrigerators,
which are older than five years old, with new energy star models will typically have paybacks of less than
10 years.
ECM #THS-1 – Setback Thermostat for Gym
Annual Energy Savings Installed Cost SIR Payback (years)
$1,762 $400 66.09 0.2
Significant energy savings exist by reducing the room temperature of the gym area during unoccupied
times. By reducing the temperature of the gymnasium space to 60F during unoccupied times, the heating
load required from the boiler and the amount of heating oil burned will be reduced. See item 2 in
Appendix D for more information.
ECM #THS-2 – Setback Thermostat for Classroom and Hallway Spaces
Annual Energy Savings Installed Cost SIR Payback (years)
$4,877 $1,400 52.28 0.3
Significant energy savings exist by reducing the room temperature of the classrooms and hallway spaces
during unoccupied times. By reducing the temperature of the classroom and hallway spaces to 60F during
unoccupied times, the heating load required from the boiler will be reduced. This will in turn reduce the
amount of heating oil burned. See item 3 in Appendix D for more information.
ECM #THS-3– Install Occupancy Sensors in Restrooms
Annual Energy Savings Installed Cost SIR Payback (years)
$840 $400 29.74 0.5
The lighting in the restrooms is currently controlled by a keyed switch. The lights were on continuously
during the CEI site visit. This measure consists of installing two ceiling mounted occupancy sensors, one
in each restroom. This description is for a compilation of several ECM’s that are intended to be
implemented at the same time, however due to constraints with the AkWarm modeling software the
different lighting configurations were modeled separately. See items 4 and 5 in Appendix D for details of
individual measures.
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ECM #THS-4– Relamp Maintenance Closet Light Fixture
Annual Energy Savings Installed Cost SIR Payback (years)
$46 $10 12.94 0.2
There is a light fixture in the 1st floor maintenance closet that uses two 60W incandescent lamps. This
improvement consists of replacing the lamps with 20W CFL lamps. See item 6 in Appendix D.
ECM #THS-5 – Setback Thermostat for Storage and Intermittent Use Spaces
Annual Energy Savings Installed Cost SIR Payback (years)
$339 $400 12.70 1.2
Significant energy savings exist by reducing the room temperature of the storage and intermittent use
areas during unoccupied times. By reducing the temperature of these spaces to 60F during unoccupied
times, the heating load required from the boiler will be reduced. This will in turn reduce the amount of
heating oil burned. See item 7 in Appendix D for more information.
ECM #THS-6– Upgrade Classroom Lighting
Annual Energy Savings Installed Cost SIR Payback (years)
$1,030 $3,150 4.60 3.1
Currently, the classroom lighting consists of manually switched, recessed troffer, four lamp, T8
fluorescent, wrap fixtures. The fixtures are equipped with a mix of electronic and magnetic ballasts. The
lighting levels were measured at 100 foot-candles. This is double the level currently recommended by the
Illuminating Engineering Society of North America (IESNA). The level can safely be reduced to 50 foot-
candles without negatively impacting occupant safety, productivity, or comfort.
This improvement consists of installing retrofit kits in all (18) existing light fixtures. The kits will convert
the fixtures to (2) lamp T8 volumetric fixtures with bi-level switching capability. This ECM will also add
a ceiling mounted occupancy sensor to each classroom. The occupancy sensors will turn off the lights
when no motion is sensed and would turn on to 50% level when motion was sensed. The lights would
have to be manually turned on to full brightness. See item 8 in Appendix D.
Note that similar retrofit kits are available to convert the light fixtures to a 50W LED source with
continuous dimming. This results in greater energy savings, but has a higher installed cost. The LED
retrofit scenario was modeled. It resulted in an annual energy savings of $1,134, an installed cost of
$6,660, a SIR of 2.43, and a payback of 5.9 years.
ECM #THS-7– Upgrade Exterior Lighting
Annual Energy Savings Installed Cost SIR Payback (years)
$1,670 $6,000 2.66 3.6
Currently, the exterior lighting consists of HPS and incandescent fixtures which are in poor condition.
This improvement consists of replacing all existing exterior light fixtures with LED fixtures. The (6)
incandescent fixtures near doors would be replaced with (6) 20W LED fixtures, the (6) HPS wall packs
would be replaced with (6) 30W LED fixtures. All fixtures would be controlled by photocell via
centralized contactor. All fixtures would have integral motion sensors to reduce lighting levels to 30%
when no motion is sensed.
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This description is for a compilation of several ECM’s that are intended to be implemented at the same
time, however due to constraints with the AkWarm modeling software the different lighting
configurations were modeled separately. See items 11 and 13 in Appendix D for details of individual
measures.
ECM #THS-8– Replace Gym Lighting
Annual Energy Savings Installed Cost SIR Payback (years)
$1,210 $6,500 2.60 5.4
Currently, the gym lighting consists of single lamp, T12 fluorescent strip fixtures and exposed
incandescent lamps with wire guards. The lighting levels are approximately 20 foot candles, below the
IESNA recommended levels of 30-50 fc.
This improvement consists of replacing all existing gym light fixtures with six, (6) lamp, T5HO
fluorescent high-bay fixtures. This improvement would also add bi-level switching and occupancy sensor
control. The lighting levels would be approximately 60 foot-candles at the high setting and 20 foot-
candles at the low setting. Four wall-mounted occupancy sensors with wire-guards would be installed.
The occupancy sensors will turn off the lights when no motion is sensed and would turn on the lower
lighting level when motion was sensed. The lights would have to be manually turned on to full brightness.
This description is for a compilation of several ECM’s that are intended to be implemented at the same
time, however due to constraints with the AkWarm modeling software the different lighting
configurations were modeled separately. See items 1 & 13 in Appendix D for details of individual
measures.
ECM #THS-9– Replace Exterior Doors
Annual Energy Savings Installed Cost SIR Payback (years)
$325 $3,500 2.55 10.8
The school's exterior doors are all original installation and have low R-values compared with current
insulation technologies available for exterior doors. Energy savings can be achieved by replacing all of
the exterior doors with new, better insulated doors with a minimum R-value of R-6.25. See items 10, 14,
and 16 in Appendix D for more information. This also has a positive impact on ECM #THS-13.
ECM #THS-10– Upgrade Hallway Lighting
Annual Energy Savings Installed Cost SIR Payback (years)
$440 $2,600 2.40 5.9
Currently, the hallway lighting consists of manually switched, surface mounted T8 fluorescent wrap
fixtures. The fixtures have a mix of electronic and magnetic ballasts.
This improvement consists of replacing all existing ballasts with high-efficiency electronic ballasts with
bi-level switching capability and occupancy sensor control. The occupancy sensors would reduce the light
level (and energy use) to 50% when no motion is sensed, and turn the lights to 100% when motion is
sensed. The lights would have to be manually turned off when the school is closed. This ECM would
require the replacement of (8) ballasts, the installation of approximately (4) occupancy sensors, and minor
rewiring.
This description is for a compilation of several ECM’s that are intended to be implemented at the same
time, however due to constraints with the AkWarm modeling software the different lighting
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configurations were modeled separately. See items 9 & 15 in Appendix D for details of individual
measures.
ECM #THS-11– Replace Exterior Windows
Annual Energy Savings Installed Cost SIR Payback (years)
$687 $10,100 1.26 15.32
Currently, the windows for the school are double paned, wood framed glass with an estimated R-1.1
insulating value. It is recommended that these windows be removed and replaced with new R-3 minimum
(U-0.30) vinyl framed, double paned windows. See items 18 and 19 in Appendix D for more information.
ECM #THS-12 – Air Tightening
Annual Energy Savings Installed Cost SIR Payback (years)
$2,373 $22,000 1.11 9.3
By tightening the building envelope with air sealing improvements, infiltration into the building will be
reduced. This in turn will reduce the heating load required by the building and reduce the amount of fuel
oil being burned by the boilers. While a blower door test was not completed, it is anticipated that air
leakage is occurring though weather stripping around doors, window frames, and wall and roof
penetrations. Leakage is also expected to be occurring through the outdoor air vents in the crawlspace
areas. Methods to decrease the infiltration into the building include: sealing around the windows and
doors with caulking and insulation, adding new weather stripping to doors, providing gaskets to all
exterior cover plates and sealing all roof and wall penetrations. To achieve a viable economic benefit,
$22,000 can be invested and still achieve an SIR ≥ 1by reducing air leakage by 20%. See item 20 in
Appendix D for more information.
ECM #THS-13– Replace Furnaces
Annual Energy Savings Installed Cost SIR Payback (years)
$1,430 $20,000 0.93 14
Although this ECM does not have an SIR above one according to the AkWarm model, it should still be
considered as an energy conservation measure. The existing furnaces installed in the school are not
energy efficient and have exceeded their useful life. By installing new energy efficient furnaces with a
variable speed blower motor, the amount of electricity and fuel oil used by the furnaces will decrease.
See item 22 in Appendix D for more information.
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VIII.II Portable Building
There are three portable buildings that exist on site. The teacher housing building is connected to the
school’s heating water system and is the only portable building that is heated. The remaining two
portables, the cold storage building and the utility outbuilding, are not heated. The cold storage building
has also been disconnected from any electrical services. The following ECM savings and installed costs
are for the teacher housing portable building.
ECM #PB-1 – Setback Thermostat
Annual Energy Savings Installed Cost SIR Payback (years)
$343 $400 12.86 1.2
Significant energy savings exist by reducing the room temperature of the teacher housing portable during
unoccupied times. By reducing the temperature of the space to 65F during unoccupied times, the heating
load required from the boiler will be reduced. This will in turn reduce the amount of heating oil burned.
ECM #PB-2 – Replace Exterior Doors
Annual Energy Savings Installed Cost SIR Payback (years)
$239 $1,500 4.42 6.1
The building has two poorly insulated (R-1.7) metal doors. It is recommended that both doors be removed
and replaced with a new R-6.25 minimum (U-0.16) insulated door. This also has a positive impact on
ECM #PB-6.
ECM #PB-3 – Install Floor Insulation
Annual Energy Savings Installed Cost SIR Payback (years)
$294 $2,900 2.73 9.9
The teacher housing portable has poorly insulated floors above the crawlspace area. This allows heat loss
through the floor and the crawlspace. It is recommended that the underside of the floor be insulated with
R-14 rigid insulation, on top of the existing insulation, to reduce this heat loss.
ECM #PB-4 – Install Additional Insulation to Exterior Walls
Annual Energy Savings Installed Cost SIR Payback (years)
$705 $12,200 1.57 17.2
The teacher housing portable building has poorly insulated exterior walls, with R-values of 11.4. It is
recommended that R-10 rigid foam board be added to the exterior, along with T-11 siding, to increase the
R-value of the wall to an R-20 and to tighten the building envelope.
ECM #PB-5 – Replace Exterior Windows
Annual Energy Savings Installed Cost SIR Payback (years)
$359 $6,800 1.03 18.8
The existing windows in the teacher housing portable building are double pane, wood framed windows
with an R-value of R-1.8. By replacing these windows with a better insulated window, thermal loss
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through the windows will be reduced. It is recommended that these doors be removed and replaced with
new R-4.5 minimum (U-0.22) insulated vinyl windows.
ECM #PB-6 – Seal Building Envelope and Reduce Infiltration by 30%
Annual Energy Savings Installed Cost SIR Payback (years)
$691 $7,000 1.02 10.1
By tightening the building envelope with air sealing improvements, infiltration into the building will be
reduced. This in turn will reduce the heating load required by the building and reduce the amount of fuel
oil being used by the boiler. Reducing infiltration by air sealing the building envelope will produce
energy savings. While a blower door test was not completed, it is anticipated that air leakage is occurring
around old weather stripping around doors, window frames, through the crawlspace, and wall and roof
penetrations. Methods to decrease the infiltration into the building include: sealing around the windows
and doors with caulking and insulation, adding new weather stripping to doors, providing gaskets to all
exterior cover plates and sealing all roof, floor, and wall penetrations. To achieve a viable economic
benefit, $7,000 can be invested and still achieve an SIR ≥ 1by reducing air leakage by 30%.
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VIII.III Administrative Controls for Energy Conservation and Optimization
While the intent of many energy conservation measures is to increase the efficiency of fuel-burning and
electrical equipment, an important factor of energy consumption lies in the operational profiles which
control the equipment usage. Such profiles can be managed by administrative controls and departmental
leadership. They determine how and when fuel-burning and electrical equipment are used, and therefore
have a greater impact on energy savings potential than simply equipment upgrades alone. Significant
energy cost savings can be realized when ECMs are combined with efficient-minded operational profiles.
Operational profiles may be outlined by organization policy or developed naturally or historically. These
profiles include, but are not limited to: operating schedules, equipment setpoints and control strategies,
maintenance schedules, and site and equipment selection.
Optimization of operational profiles can be accomplished by numerous methods so long as the intent is
reduction in energy-using equipment runtime. Due to the numerous methods of optimization, energy cost
savings solely as a result of operational optimization are difficult to predict. Quantification, however, is
easy to accomplish by metering energy usage during and/or after implementation of energy-saving
operational profiles and ECMs. Shown below are some examples which have proven successful for other
organizations.
Optimization of site selection includes scheduling and location of events. If several buildings in a given
neighborhood are all lightly used after regularly occupied hours, energy savings can be found when after-
hours events are consolidated and held within the most energy efficient buildings available for use. As a
result, unoccupied buildings could be shut down to the greatest extent possible to reduce energy
consumption.
Two operational behaviors which can be combined with equipment upgrades are operating schedules and
equipment control strategies including setpoints. Occupancy and daylight sensors can be programmed to
automatically shut off or dim lighting when rooms are unoccupied or sufficiently lit from the sun.
Operating schedules can be optimized to run equipment only during regular or high-occupancy periods.
Also, through a central control system, or with digital programmable thermostats, temperature setpoints
can be reduced during low-occupancy hours to maximize savings. In addition, sporadically used
equipment can be shut down during unoccupied hours to further save energy. In general, having
equipment operating in areas where no occupants are present is inefficient, and presents an opportunity
for energy savings.
Operational profiles can also be implemented to take advantage of no- or low-cost ECMs. Examples
include heating plant optimizations (boiler section cleaning, boiler flush-through cleaning) and tighter
controls of equipment setbacks and shutdowns (unoccupied zones equipment shutdown, easier access to
and finer control of equipment for after-hours control). In a large facility management program,
implementation of these measures across many or all sites will realize dramatic savings due to the
quantity of equipment involved.
Changes to building operational profiles can only be realized while simultaneously addressing health,
safety, user comfort, and user requirements first. It is impractical to expect users to occupy a building or
implement operational behaviors which do not meet such considerations. That said, it is quite practical for
management groups to implement administrative controls which reduce losses brought about by excess
and sub-optimum usage.
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Appendix A
Energy Benchmark Data
Twin Hills K-12 School Draft Energy Audit Report
SW Region School District Regional Education Attendance 05/09/11
REAL Preliminary Benchmark Data Form
PART I – FACILITY INFORMATION
Facility Owner Facility Owned By Date
Building Name/ Identifier Building Usage Building Square Footage
Twin Hills School 7,360
Building Type Community Population Year Built
First Name Last Name Middle Name Phone
Rick Dallmann 842‐5280
Building Type Community Population Year Built
Mixed 75 1979
Facility Address Facility City Facility Zip
Twin Hills 99576
Contact Person
Email
rdallmann@swrsd.org
l dd State Zip
AK 99576
Monday‐
Friday
Saturday Sunday Holidays
8 to 50 0 0
Average # of
Mailing Address City
P.O. Box 90 Dillingham
Primary
Operating
Hours
Occupants
During
Operating
Hours
24
Renovations/Notes
Date
None
Note: Specific information on drawings is unavailable from facility owner.
Details
What drawings may be available are maintained at the school for maintenance.
PART II – ENERGY SOURCES
1. Please check every energy source you use in the table below. If known, please enter the base rate you
2 Pidtiliti bill f th t t t idf h
Heating Oil Electricity Natural Gas Propane Wood Coal
$ /gallon $ / kWh $ / CCF $ / gal $ / cord $ / ton
Other energy
sources?
2. Provide utilities bills for the most recent two‐year period for each energy source you use.
Describe
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Twin Hills K-12 School Draft Energy Audit Report
Twin Hills
Buiding Size Input (sf) =7,360
2009 Natural Gas Consumption (Therms)p( )
2009 Natural Gas Cost ($)
2009 Electric Consumption (kWh)14,790
2009 Electric Cost ($)8,161
2009 Oil Consumption (Therms)16,236
2009 Oil Cost ($)66,912
2009 Total Energy Use (kBtu)1,674,078
2009 T t l E C t ($)75 0732009 Total Energy Cost ($)75,073
Annual Energy Use Intensity (EUI)
2009 Natural Gas (kBtu/sf)
2009 Electricity (kBtu/sf)6.9
2009 Oil (kBtu/sf) 220.6
2009 Energy Utilization Index (kBtu/sf)227.5
Annual Energy Cost Index (ECI)gy ( )
2009 Natural Gas Cost Index ($/sf)
2009 Electric Cost Index ($/sf)1.11
2009 Oil Cost Index ($/sf)9.09
2009 Energy Cost Index ($/sf)10.20
2010 Natural Gas Consumption (Therms)
2010 N t l G C t ($)2010 Natural Gas Cost ($)
2010 Electric Consumption (kWh)15,150
2010 Electric Cost ($)8,359
2010 Oil Consumption (Therms)16,962
2010 Oil Cost ($)49,473
2010 Total Energy Use (kBtu)1,747,907
2010 Total Energy Cost ($)57,8320 0 ota e gy Cost ($)5,83
Annual Energy Use Intensity (EUI)
2010 Natural Gas (kBtu/sf)
2010 Electricity (kBtu/sf)7.0
2010 Oil (kBtu/sf)230.5
2010 Energy Utilization Index (kBtu/sf)237.5
Annual Energy Cost Index (ECI)
2010 N t l G C t I d ($/ f)2010 Natural Gas Cost Index ($/sf)
2010 Electric Cost Index ($/sf)1.14
2010 Oil Cost Index ($/sf)6.72
20010 Energy Cost Index ($/sf)7.86
Note:
1kWh=3,413 Btu's1 kWh 3,413 Btus
1 Therm = 100,000 Btu's
1 CF ≈ 1,000 Btu's
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Twiudit Report Twin HillsElectricityBtus/kWh =3,413Provider Customer #Month Start Date End Date Billing Days Consumption (kWh) Consumption (Therms) Demand Use Electric Cost ($) Unit Cost ($/kWh) Demand Cost ($)THVC Jan‐09 1/1/2009 1/31/2009 311,450 49 $800 $0.55THVC Feb‐09 2/1/2009 2/28/2009 281,220 42 $673 $0.55////$$THVCMar‐09 3/1/2009 3/31/2009311,58054$871$0.55THVC Apr‐09 4/1/2009 4/30/2009 301,450 49 $800 $0.55THVC May‐09 5/1/2009 5/31/2009 311,160 40 $640 $0.55THVC Jun‐09 6/1/2009 6/30/2009 30 980 33 $541 $0.55THVC Jul‐09 7/1/2009 7/31/2009 31 800 27 $442 $0.55THVC Aug‐09 8/1/2009 8/31/2009 31 940 32 $519 $0.55THVC Sep‐09 9/1/2009 9/30/2009 30 1,200 41 $662 $0.55THVC Oct‐09 10/1/2009 10/31/2009 31 1,450 49 $800 $0.55THVCNov0911/1/200911/30/2009302 37081$1 306$0 55THVCNov‐0911/1/200911/30/2009302,37081$1,306$0.55THVCDec‐09 12/1/2009 12/31/2009311906$107$0.56THVCJan‐10 1/1/2010 1/31/2010311,45049$800$0.55THVCFeb‐10 2/1/2010 2/28/2010281,22042$673$0.55THVCMar‐10 3/1/2010 3/31/2010311,58054$871$0.55THVCApr‐10 4/1/2010 4/30/2010301,45049$800$0.55THVCMay‐10 5/1/2010 5/31/2010311,16040$640$0.55THVCJun‐106/1/20106/30/20103052018$288$0.55THVCJun 106/1/20106/30/20103052018$288$0.55THVCJul‐10 7/1/2010 7/31/20103155019$305$0.55THVCAug‐10 8/1/2010 8/31/2010311,02035$563$0.55THVCSep‐10 9/1/2010 9/30/2010301,38047$761$0.55THVCOct‐10 10/1/2010 10/31/2010311,42048$783$0.55THVCNov‐10 11/1/2010 11/30/2010301,63056$899$0.55THVCDec‐10 12/1/2010 12/31/2010311,77060$976$0.55Jan ‐ 09 to Dec ‐ 09 total:14,7905050$8,161$0Jan ‐ 10 to Dec ‐ 10 total:15,1505170$8,359$0$0.55$0.55Note:Missing electrical data , colored red in this table, from January to May 2009 was estimated in order to arrive at the averages in this table. To estimate the missing data, values from similar months in other years was used.Jan ‐ 10 to Dec ‐ 10 avg:Jan ‐ 09 to Dec ‐ 09 avg:Coffman Engineers, Inc.AkWarm No. BBNC-A63-CAEC-01Coffman Engineers, Inc. AkWarm No. BBNC-A63-CAEC-01 Coffman Engineers, Inc. AkWarm No. BBNC-A63-CAEC-01 Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Twin Hills K-12 SchoolDraft Energy Audit Report $1,4002,500Twin Hills ‐Electric Consumption (kWh) vs. Electric Cost ($)$1,000$1,2002,000)$600$8001,0001,500Electric Cost ($)ric Consumption (kWh)Electric Consumption (kWh)Electric Cost ($)$0$200$4000500Electr$00Date (Mon ‐Yr)Coffman Engineers, Inc.AkWarm No. BBNC-A63-CAEC-01Coffman Engineers, Inc. AkWarm No. BBNC-A63-CAEC-01 Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Twin Hills K-12 SchoolDraft Energy Audit Report Twin HillsOilBtus/Gal =132,000Provider Customer #Month Start Date End Date Billing Days Consumption (Gal) Consumption (Therms) Demand Use Oil Cost ($) Unit Cost ($/Therm) Demand Cost ($)Jul‐08 7/1/2008 7/31/20083100$00.00Aug‐08 8/1/2008 8/31/20083100$00.00Sep‐08 9/1/2008 9/30/20083000$00.00Oct‐08 10/1/2008 10/31/20083100$00.00Nov‐08 11/1/2008 11/30/20083000$00.00Dec‐08 12/1/2008 12/31/20083100$00.00Jan‐09 1/1/2009 1/31/20093100$00.00Feb‐09 2/1/2009 2/28/20092800$00.00Mar‐09 3/1/2009 3/31/2009 31 0 0 $0 0.00Apr‐09 4/1/2009 4/30/2009 30 0 0 $0 0.00May‐09 5/1/2009 5/31/2009 31 0 0 $0 0.00Jun‐09 6/1/2009 6/30/2009 3012,300 16,236 $66,912 4.12Jul‐09 7/1/2009 7/31/20093100$00.00Aug‐09 8/1/2009 8/31/20093100$00.00Sep‐09 9/1/2009 9/30/20093000$00.00Ot0910/1/200910/31/20093100$0000Oct‐0910/1/200910/31/20093100$00.00Nov‐09 11/1/2009 11/30/2009 30 0 0 $0 0.00Dec‐09 12/1/2009 12/31/2009 31 0 0 $0 0.00Jan‐10 1/1/2010 1/31/20103100$00.00Feb‐10 2/1/2010 2/28/20102800$00.00Mar‐10 3/1/2010 3/31/20103100$00.00Apr‐10 4/1/2010 4/30/20103000$00.00May‐10 5/1/2010 5/31/20103100$00.00Jun‐106/1/20106/30/20103012 85016 962$49 473292Jun‐106/1/20106/30/20103012,85016,962$49,4732.92Jul ‐ 08 to Jun ‐ 09 total:12,300 16,236 0$66,912 $0Jul ‐ 09 to Jun ‐ 10 total:12,850 16,962 0$49,473 $0Jul ‐ 08 to Jun ‐ 09 avg:4.12Jul ‐ 09 to Jun ‐ 10 avg:2.92Coffman Engineers, Inc.AkWarm No. BBNC-A63-CAEC-01Coffman Engineers, Inc. AkWarm No. BBNC-A63-CAEC-01 Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Twin Hills K-12 SchoolDraft Energy Audit Report $70 000 00$80,000.00 1600018000Twin Hills ‐Oil Consumption (Therms) vs. Oil Cost ($)$50,000.00 $60,000.00 $70,000.00 1200014000ms)$30,000.00 $40,000.00 6000800010000Oil Cost ($)Oil Consumption (ThermOil Consumption (Therms)Oil Cost ($)$10,000.00 $20,000.00 200040006000O$0.00 0Date (Mon ‐Yr)Coffman Engineers, Inc.AkWarm No. BBNC-A63-CAEC-01Coffman Engineers, Inc. AkWarm No. BBNC-A63-CAEC-01 Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Appendix B
AkWarm Commercial Reports
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
ENERGY AUDIT REPORT – PROJECT SUMMARY – Created 1/30/2012 1:26
PM
General Project Information
PROJECT INFORMATION AUDITOR INFORMATION
Building: Twin Hills K-12 Auditor Company: Coffman Engineers, Inc.
Address: Twin Hills Auditor Name: Walter Heins, PE, CCP, CxA, CEA
City: Twin Hills Auditor Address: 800 F Street
Anchorage, AK 99501 Client Name: Rick Dallmann
Client Address: P.O. Box 90
Dillingham, AK 99576
Auditor Phone: (907) 276-6664
Auditor FAX: (907) 276-5042
Client Phone: (907) 842-5280 Auditor Comment:
Client FAX:
Design Data
Building Area: 6,499 square feet Design Heating Load: Design Loss at Space: 316,243
Btu/hour
with Distribution Losses: 451,776 Btu/hour
Plant Input Rating assuming 82.0% Plant Efficiency
and 25% Safety Margin: 688,683 Btu/hour
Note: Additional Capacity should be added for DHW
load, if served.
Typical Occupancy: 24 people Design Indoor Temperature: 70 deg F (building
average)
Actual City: Twin Hills Design Outdoor Temperature: -19.3 deg F
Weather/Fuel City: Twin Hills Heating Degree Days: 11,306 deg F-days
Utility Information
Electric Utility: Twin Hills Village Council -
Commercial - Sm
Natural Gas Provider: None
Average Annual Cost/kWh: $0.550/kWh Average Annual Cost/ccf: $0.000/ccf
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 Annual Energy Cost Estimate Description Space Heating Space Cooling Water Heating Lighting Other Electrical Cooking Clothes Drying Vent Fans Service Fees Total Cost Existing Building $43,797 $0 $2,720 $14,782 $3,548 $4,415 $0 $3,611 $0 $72,874 With Proposed Retrofits $33,503 $0 $3,232 $7,819 $3,548 $4,415 $0 $2,596 $0 $55,114 SAVINGS $10,294 $0 -$512 $6,963 $0 $0 $0 $1,015 $0 $17,760
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 $0$20,000$40,000$60,000$80,000Existing RetrofitVentilation and FansSpace HeatingOther ElectricalLightingDomestic Hot WaterCookingAnnual Energy Costs by End Use
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 Annual Electrical Usage By Month
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 Annual Fuel Oil #1 Usage By Month
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Appendix C
Major Equipment List
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 MAJOR EQUIPMENT INVENTORY TAG LOCATION FUNCTION MAKE MODEL TYPE CAPACITY EFFICIENCY MOTOR SIZE ASHRAE SERVICE LIFE (YEARS) ESTIMATED REMAINING USEFUL LIFE (YEARS) B-1 UTILITY BUILDING BUILDING HEATING BURNHAM PV77WC-TBWN2S CAST IRON #1 FUEL OIL 213 MBH ≈ 73% 30 ≈ 19 B-2 UTILITY BUILDING BUILDING HEATING BURNHAM PV77WC-TBWN2S CAST IRON #1 FUEL OIL 213 MBH ≈ 73% 30 ≈ 20 B-3 UTILITY BUILDING BUILDING HEATING BURNHAM PV77WC-TBWN2S CAST IRON #1 FUEL OIL 213 MBH ≈ 73% 30 ≈ 20 CP-1 UTILITY BUILDING HEATING WATER CIRC GRUNDFOS UPC 65-160 MODEL A INLINE 40GPM 60' ≈ 75% 1.25 HP 10 ≈5 CP-2 UTILITY BUILDING HEATING WATER CIRC GRUNDFOS - INLINE 40GPM 60' ≈ 75% 1.25 HP 10 0 CP-3 BOILER RM HEATING WATER CIRC BALDOR - INLINE 40GPM ≈ 75% 1.25 HP 10 ≈5 CP-4 BOILER RM HEATING WATER CIRC GRUNDFOS - INLINE 40GPM ≈ 75% 1.25 HP 10 0 HWCP-1 BOILER RM DOMESTIC HOT WATER RECIRC GRUNDFOS - INLINE 20GPM ≈ 75% 0.25 HP 10 0 FUR-1 FURNACE ROOM GYM FURNACE LENNOX - - 3400CFM ≈ 75% - 18 0 FUR-2 FURNACE ROOM CLASSROOM FURNACE LENNOX - - 3400CFM ≈ 75% - 18 0 FUR-3 FURNACE ROOM SPARE – NEVER USED LENNOX - - 3400CFM ≈ 75% - 18 18 EF-1 FURNACE ROOM CLASSROOM TOILET EXHAUST PENN - INLINE 300CFM ≈ 75% 1/12 25 0
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Appendix D
Energy Conservation Measures
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
PRIORITY LIST – RECOMMENDED ENERGY CONSERVATION MEASURES
Rank Feature Recommendation Annual Energy
Savings
Installed
Cost
SIR Payback
(Years)
0 a Refrigerators Replace residential & light
commercial
refrigerators/freezers older
than 5 years old
-- -<10
1 Lighting: Gym
250W incandescent
Remove Manual Dimmer
and Improve Manual
Switching
$169 $1 2304.50 0
2 Setback Thermostat:
Gym
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Gym space.
$1,762 $400 66.09 0.2
3 Setback Thermostat:
Classroom, Library,
Hallway Space
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Classroom, Library, and
Hallway space.
$4,877 $1,400 52.28 0.3
4 Lighting: Restroom
(2) 32W T8
Remove Manual Switching
and Add new Occupancy
Sensor
$477 $200 33.77 0.4
5 Lighting: Restroom
(2) 40W T12 mag
Remove Manual Switching
and Add new Occupancy
Sensor
$363 $200 25.71 0.6
6 Lighting:
Intermittent 60W
incandescent
Replace with FLUOR (2)
CFL, A Lamp 20W
$46 $10 12.94 0.2
7 Setback Thermostat:
Storage/Intermittent
Use
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Storage/Intermittent
Use space.
$339 $400 12.70 1.2
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
PRIORITY LIST – RECOMMENDED ENERGY CONSERVATION MEASURES
Rank Feature Recommendation Annual Energy
Savings
Installed
Cost
SIR Payback
(Years)
8 Lighting: Classroom
(4) 32W T8
Replace with 18 FLUOR
(2) T8 4' F32T8 32W
Standard Program
HighEfficElectronic and
Add new Occupancy
Sensor
$1,030 $3,150 4.60 3.1
9 Lighting: Hall (2)
32W T8 mag
Replace with FLUOR (2)
T8 4' F32T8 32W Standard
Program
HighEfficElectronic and
Add new Multi-Level
Switch
$99 $320 4.37 3.2
10 Exterior Door:
Hollow Metal - W/O
window
Remove existing door and
install standard pre-hung U-
0.16 insulated door,
including hardware.
$199 $1,817 2.94 9.2
11 Lighting: Exterior
100W incandescent
Replace with 6 LED 20W
Module StdElectronic and
Remove Manual Switching
and Add new On/Off
Photoswitch
$878 $3,000 2.80 3.4
12 Lighting: Exterior
70W HPS wallpack
Replace with 6 LED 20W
Module StdElectronic and
Improve Occupancy Sensor
$792 $3,000 2.52 3.8
13 Lighting: Gym 48"
T12HO
Replace with 6 FLUOR (6)
T5 45.2" F54W/T5 HO
Standard
HighEfficElectronic and
Add new Multi-Level
Switch
$1,041 $6,500 2.25 6.2
14 Exterior Door: Solid
Core
Remove existing door and
install standard pre-hung U-
0.16 insulated door,
including hardware.
$49 $606 2.19 12.3
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
PRIORITY LIST – RECOMMENDED ENERGY CONSERVATION MEASURES
Rank Feature Recommendation Annual Energy
Savings
Installed
Cost
SIR Payback
(Years)
15 Lighting: Hall (2)
32W T8 elec
Replace with 7 FLUOR (2)
T8 4' F32T8 32W Standard
Program
HighEfficElectronic and
Add new Multi-Level
Switch
$338 $2,250 2.12 6.6
16 Exterior Door:
Hollow Metal -
W/Window
Remove existing door and
install standard pre-hung U-
0.16 insulated door,
including hardware.
$77 $1,009 2.07 13
17 Lighting:
Intermittent (1) 40W
T12 mag
Replace with 2 FLUOR T5
45.2" F28T5 28W Standard
HighEfficElectronic
$34 $300 1.60 8.8
18 Window/Skylight:
Double Pane
Windows - Not
South
Replace existing window
with U-0.22 vinyl window
$574 $8,298 1.33 14.5
19 Window/Skylight:
Double Pane
Windows - South
Replace existing window
with U-0.30 vinyl window
$113 $1,783 1.22 15.8
20 Air Tightening Perform air sealing to
reduce air leakage by 20%.
$2,373 $22,000 1.11 9.3
21 Lighting:
Intermittent (2) 40W
T12 mag
Replace with 2 FLUOR (2)
T5 45.2" F28T5 28W
Standard
HighEfficElectronic
$20 $300 0.96 14.6
22 Ventilation Replace Existing Furnaces
with higher efficiency
furnaces
$1,430 $20,000 0.93 14
23 Cathedral Ceiling:
Cold Roof
Fill empty 2x12 cavity with
12" dense-pack blown-in
cellulose insulation, density
at least 3.5 lb/ft3.
$752 $45,627 0.44 60.6
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
PRIORITY LIST – RECOMMENDED ENERGY CONSERVATION MEASURES
Rank Feature Recommendation Annual Energy
Savings
Installed
Cost
SIR Payback
(Years)
24 Lighting:
Intermittent
Replace with 7 FLUOR (2)
T5 45.2" F28T5 28W
Standard StdElectronic
-$13 $1,400 -0.13 -107.5
25 Lighting: Library (2)
32W T8
Replace with 10 FLUOR
(2) T5 45.2" F28T5 28W
Standard StdElectronic
-$58 $2,000 -0.41 -34.5
TOTAL $17,760 $125,971 2.03 7.1
Notes:
a Due to advances in refrigerators in the previous 5 years, new Energy Star refrigerators are much more
efficient and result in viable energy savings.
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
ENERGY AUDIT REPORT – ENERGY EFFICIENT RECOMMENDATIONS
1. Building Envelope
Insulation
Rank Location Existing Type/R-Value Recommendation Type/R-
Value
Installed
Cost
Annual
Energy
Savings
23 Cathedral
Ceiling: Cold
Roof
Framing Type: I-Beam
(TJI)
Framing Spacing: 24 inches
Insulated Sheathing: None
Bottom Insulation Layer:
R-19 Batt:FG or RW, 6
inches
Top Insulation Layer: R-13
Batt:FG or RW, 3.63 inches
Insulation Quality:
Damaged
Modeled R-Value: 32.7
Fill empty 2x12 cavity
with 12" dense-pack
blown-in cellulose
insulation, density at least
3.5 lb/ft3.
$45,627 $752
Exterior Doors – Replacement
Rank Location Size/Type/Condition Recommendation Installed
Cost
Annual
Energy
Savings
10 Exterior Door:
Hollow Metal -
W/O window
Door Type: Metal -
fiberglass or mineral wool
Modeled R-Value: 1.7
Remove existing door
and install standard pre-
hung U-0.16 insulated
door, including hardware.
$1,817 $195
14 Exterior Door:
Solid Core
Door Type: Wood - hollow
flush
Modeled R-Value: 2.1
Remove existing door
and install standard pre-
hung U-0.16 insulated
door, including hardware.
$606 $49
16 Exterior Door:
Hollow Metal -
W/Window
Door Type: Metal/FG half
lite
Modeled R-Value: 2.2
Remove existing door
and install standard pre-
hung U-0.16 insulated
door, including hardware.
$1,009 $77
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Windows and Glass Doors – Replacement
Rank Location Size/Type/Condition Recommendation Installed
Cost
Annual
Energy
Savings
19 Window/Skylig
ht: Double Pane
Windows - Not
South
Glass: Single, Glass
Frame: Wood\Vinyl
Spacing Between Layers:
Half Inch
Gas Fill Type: Air
Modeled U-Value: 0.94
Solar Heat Gain Coefficient
including Window
Coverings: 0.52
Replace existing window
with U-0.22 vinyl
window
$8,298 $574
22 Window/Skylig
ht: Double Pane
Windows -
South
Glass: Single, Glass
Frame: Wood\Vinyl
Spacing Between Layers:
Half Inch
Gas Fill Type: Air
Modeled U-Value: 0.94
Solar Heat Gain Coefficient
including Window
Coverings: 0.52
Replace existing window
with U-0.30 vinyl
window
$1,783 $113
Air Leakage
Rank Location Estimated Air Leakage Recommended Air Leakage
Target
Installed
Cost
Annual
Energy
Savings
13 Air Tightness estimated as:
1.30 cfm/ft2 of above-grade
shell area at 75 Pascals
Perform air sealing to
reduce air leakage by
20%.
$22,000 $2,373
2. Mechanical Equipment
Mechanical
Rank Recommendation Installed
Cost
Annual
Energy
Savings
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Setback Thermostat
Rank Location Size/Type/Condition Recommendation Installed
Cost
Annual
Energy
Savings
2 Gym Existing Unoccupied
Heating Setpoint: 70.0 deg
F
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Gym space.
$400 $1,762
3 Classroom,
Library,
Hallway Space
Existing Unoccupied
Heating Setpoint: 70.0 deg
F
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Classroom, Library,
and Hallway space.
$1,400 $4,877
7 Storage/Intermit
tent Use
Existing Unoccupied
Heating Setpoint: 70.0 deg
F
Implement a Heating
Temperature Unoccupied
Setback to 60.0 deg F for
the Storage/Intermittent
Use space.
$400 $339
Ventilation
Rank Recommendation Cost Annual
Energy
Savings
22 Replace Existing Furnaces with higher efficiency furnaces $20,000 $1,430
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
3. Appliances and Lighting
Lighting Fixtures and Controls
Rank Location Existing Recommended Installed
Cost
Annual
Energy
Savings
1 Gym 250W
incandescent
INCAN A Lamp, Std 200W
with Manual Switching,
Manual Dimmer
Remove Manual Dimmer
and Improve Manual
Switching
$1 $169
4 Restroom (2)
32W T8
4 FLUOR (2) T8 4' F32T8
32W Standard Program
StdElectronic with Manual
Switching
Remove Manual
Switching and Add new
Occupancy Sensor
$200 $477
5 Restroom (2)
40W T12 mag
FLUOR (4) T12 4' F40T12
40W Standard Magnetic
with Manual Switching
Remove Manual
Switching and Add new
Occupancy Sensor
$200 $363
6 Intermittent
60W
incandescent
INCAN (2) A Lamp, Std
60W with Manual
Switching
Replace with FLUOR (2)
CFL, A Lamp 20W
$10 $46
8 Classroom (4)
32W T8
18 FLUOR (4) T8 4' F32T8
32W Standard (2) Instant
StdElectronic with Manual
Switching, Multi-Level
Switch
Replace with 18 FLUOR
(2) T8 4' F32T8 32W
Standard Program
HighEfficElectronic and
Add new Occupancy
Sensor
$3,150 $1,030
9 Hall (2) 32W T8
mag
FLUOR (2) T8 4' F32T8
32W Standard (2) Program
EfficMagnetic with Manual
Switching
Replace with FLUOR (2)
T8 4' F32T8 32W
Standard Program
HighEfficElectronic and
Add new Multi-Level
Switch
$320 $99
11 Exterior 100W
incandescent
6 INCAN A Lamp, Std
100W with Manual
Switching
Replace with 6 LED 20W
Module StdElectronic
and Remove Manual
Switching and Add new
On/Off Photoswitch
$3,000 $878
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
3. Appliances and Lighting
Lighting Fixtures and Controls
Rank Location Existing Recommended Installed
Cost
Annual
Energy
Savings
12 Exterior 70W
HPS wallpack
6 HPS 70 Watt Magnetic
with On/Off Photoswitch
Replace with 6 LED 20W
Module StdElectronic
and Improve Occupancy
Sensor
$3,000 $792
13 Gym 48"
T12HO
6 FLUOR T12 4'
F48T12/HO 60W Standard
Magnetic with Manual
Switching
Replace with 6 FLUOR
(6) T5 45.2" F54W/T5
HO Standard
HighEfficElectronic and
Add new Multi-Level
Switch
$6,500 $1,041
15 Hall (2) 32W T8
elec
7 FLUOR (2) T8 4' F32T8
32W Standard Program
StdElectronic with Manual
Switching
Replace with 7 FLUOR
(2) T8 4' F32T8 32W
Standard Program
HighEfficElectronic and
Add new Multi-Level
Switch
$2,250 $338
17 Intermittent (1)
40W T12 mag
2 FLUOR T12 4' F40T12
40W Standard Magnetic
with Manual Switching
Replace with 2 FLUOR
T5 45.2" F28T5 28W
Standard
HighEfficElectronic
$300 $34
21 Intermittent (2)
40W T12 mag
2 FLUOR (2) T12 4'
F40T12 40W Standard
Magnetic with Manual
Switching
Replace with 2 FLUOR
(2) T5 45.2" F28T5 28W
Standard
HighEfficElectronic
$300 $20
24 Intermittent 7 FLUOR (2) T8 4' F32T8
32W Standard Program
StdElectronic with Manual
Switching
Replace with 7 FLUOR
(2) T5 45.2" F28T5 28W
Standard StdElectronic
$1,400 -$13
25 Library (2) 32W
T8
10 FLUOR (2) T8 4' F32T8
32W Standard Program
StdElectronic with Manual
Switching
Replace with 10 FLUOR
(2) T5 45.2" F28T5 28W
Standard StdElectronic
$2,000 -$58
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
3. Appliances and Lighting
Lighting Fixtures and Controls
Rank Location Existing Recommended Installed
Cost
Annual
Energy
Savings
26 Intermittent 7 FLUOR (2) T8 4' F32T8
32W Standard Program
StdElectronic with Manual
Switching
Replace with 7 FLUOR
(2) T5 45.2" F28T5 28W
Standard StdElectronic
$1,400 -$13
27 Library (2) 32W
T8
10 FLUOR (2) T8 4' F32T8
32W Standard Program
StdElectronic with Manual
Switching
Replace with 10 FLUOR
(2) T5 45.2" F28T5 28W
Standard StdElectronic
$2,000 -$58
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Appendix E
Site Visit Photos
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
1. West Entrance 2. East Side
3. South Side 4. North Side
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
5. Cold Storage 6. School, Teacher Housing, and Fuel Oil Tank
7. Teacher Housing – East Entrance 8. Teacher Housing – West Entrance
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
9. B-1, B-2, and B-3 10. CP-1
11. Pumps CP-1 and CP-2 12. Pumps CP-3 and CP-4
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
13. School Emergency Generator 14. Old School Emergency Generator
15. Fuel Oil Day Tank 16. FUR-1
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
17. FUR-2 18. FUR-3
19. FUR-1 and FUR-3 20. EF-1
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
21. WH-1 22. HWCP-1
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Appendix F
AkWarm Model of Portable Building
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
ENERGY AUDIT REPORT – PROJECT SUMMARY – Created 1/30/2012 2:41
PM
General Project Information
PROJECT INFORMATION AUDITOR INFORMATION
Building: Twin Hills K-12 School- Portable
Building
Auditor Company: Coffman Engineers, Inc.
Address: Twin Hills Auditor Name: Walter Heins, PE, CCP, CxA, CEA
City: Twin Hills Auditor Address: 800 F Street
Anchorage, AK 99501 Client Name: Rick Dallmann
Client Address: PO Box 90
Dillingham, AK 99576
Auditor Phone: (907) 276-6664
Auditor FAX: (907) 276-5042
Client Phone: (907) 842-5280 Auditor Comment:
Client FAX:
Design Data
Building Area: 861 square feet Design Heating Load: Design Loss at Space: 35,238
Btu/hour
with Distribution Losses: 50,340 Btu/hour
Plant Input Rating assuming 82.0% Plant Efficiency
and 25% Safety Margin: 76,737 Btu/hour
Note: Additional Capacity should be added for DHW
load, if served.
Typical Occupancy: 4 people Design Indoor Temperature: 70 deg F (building
average)
Actual City: Twin Hills Design Outdoor Temperature: -19.3 deg F
Weather/Fuel City: Twin Hills Heating Degree Days: 11,306 deg F-days
Utility Information
Electric Utility: Twin Hills Village Council -
Commercial - Sm
Natural Gas Provider: None
Average Annual Cost/kWh: $0.550/kWh Average Annual Cost/ccf: $0.000/ccf
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 Annual Energy Cost Estimate Description Space Heating Space Cooling Water Heating Lighting Other Electrical Cooking Clothes Drying Vent Fans Service Fees Total Cost Existing Building $8,073 $0 $677 $0 $0 $0 $0 $0 $0 $8,750 With Proposed Retrofits $5,401 $0 $719 $0 $0 $0 $0 $0 $0 $6,120 SAVINGS $2,672 $0 -$42 $0 $0 $0 $0 $0 $0 $2,630
Twin Hills K-12 School Final Energy Audit Report Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01 $0$2,000$4,000$6,000$8,000$10,000Existing RetrofitSpace HeatingDomestic Hot WaterAnnual Energy Costs by End Use
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
PRIORITY LIST – RECOMMENDED ENERGY CONSERVATION MEASURES
Rank Feature Recommendation Annual Energy
Savings
Installed
Cost
SIR Payback
(Years)
0 a Refrigerators Replace residential & light
commercial
refrigerators/freezers older
than 5 years old
-- -<10
1 Setback Thermostat:
Portable Building
Implement a Heating
Temperature Unoccupied
Setback to 65.0 deg F for
the Portable Building space.
$343 $400 12.86 1.2
2 Exterior Door:
Portable Building -
Doors
Remove existing door and
install standard pre-hung U-
0.16 insulated door,
including hardware.
$239 $1,454 4.42 6.1
3 Exposed Floor:
Portable Building -
Floor
Install R-14 rigid board
insulation
$294 $2,907 2.73 9.9
4 Above-Grade Wall:
Portable Building -
2x4 Stud Wall
Install R-10 rigid foam
board to exterior and cover
with T1-11 siding or
equivalent.
$705 $12,119 1.57 17.2
5 Window/Skylight:
Portable Building -
Double Pane
Windows
Replace existing window
with U-0.22 vinyl window
$359 $6,724 1.03 18.8
6 Air Tightening Perform air sealing to
reduce air leakage by 30%.
$691 $7,000 1.02 10.1
TOTAL $2,630 $30,604 1.72 11.6
Notes:
a Due to advances in refrigerators in the previous 5 years, new Energy Star refrigerators are much more
efficient and result in viable energy savings.
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
ENERGY AUDIT REPORT – ENERGY EFFICIENT RECOMMENDATIONS
2. Building Envelope
Insulation
Rank Location Existing Type/R-Value Recommendation Type/R-
Value
Installed
Cost
Annual
Energy
Savings
3 Exposed Floor:
Portable
Building - Floor
Framing Type: 2 x Lumber
Insulating Sheathing: None
Top Insulation Layer: None
Bottom Insulation Layer:
R-11 Batt:FG or RW, 3.5
inches
Modeled R-Value: 23.1
Install R-14 rigid board
insulation
$2,907 $294
4 Above-Grade
Wall: Portable
Building - 2x4
Stud Wall
Wall Type: Single Stud
Siding Configuration: Just
Siding
Insul. Sheathing: None
Structural Wall: 2 x 4, 16
inches on center
R-13 Batt:FG or RW, 3.5
inches
Window and door headers:
Not Insulated
Modeled R-Value: 11.4
Install R-10 rigid foam
board to exterior and
cover with T1-11 siding
or equivalent.
$12,119 $705
Exterior Doors – Replacement
Rank Location Size/Type/Condition Recommendation Installed
Cost
Annual
Energy
Savings
2 Exterior Door:
Portable
Building - Doors
Door Type: Metal -
fiberglass or mineral wool
Modeled R-Value: 1.7
Remove existing door
and install standard pre-
hung U-0.16 insulated
door, including hardware.
$1,454 $239
Twin Hills K-12 School Final Energy Audit Report
Coffman Engineers, Inc. 6/8/2012 AkWarm No. BBNC-A63-CAEC-01
Windows and Glass Doors – Replacement
Rank Location Size/Type/Condition Recommendation Installed
Cost
Annual
Energy
Savings
5 Window/Skylig
ht: Portable
Building -
Double Pane
Windows
Glass: Double, glass
Frame: Wood\Vinyl
Spacing Between Layers:
Quarter Inch
Gas Fill Type: Air
Modeled U-Value: 0.56
Solar Heat Gain Coefficient
including Window
Coverings: 0.46
Replace existing window
with U-0.22 vinyl
window
$6,724 $359
Air Leakage
Rank Location Estimated Air Leakage Recommended Air Leakage
Target
Installed
Cost
Annual
Energy
Savings
6 Air Tightness estimated as:
0.66 cfm/ft2 of above-grade
shell area at 75 Pascals
Perform air sealing to
reduce air leakage by
30%.
$7,000 $691
2. Mechanical Equipment
Mechanical
Rank Recommendation Installed
Cost
Annual
Energy
Savings
Setback Thermostat
Rank Location Size/Type/Condition Recommendation Installed
Cost
Annual
Energy
Savings
1 Portable
Building
Existing Unoccupied
Heating Setpoint: 70.0 deg
F
Implement a Heating
Temperature Unoccupied
Setback to 65.0 deg F for
the Portable Building
space.
$400 $343