HomeMy WebLinkAboutSEA-AEE-Craig High School 2012-EE
Craig High School
Craig City School District
Funded by:
Final Report
October 2011
Prepared by:
Energy Audit
Table of Contents
Section 1: Executive Summary 2
Section 2: Introduction 7
Section 3: Energy Efficiency Measures 9
Section 4: Description of Systems 17
Section 5: Methodology 20
Appendix A: Energy and Life Cycle Cost Analysis 23
Appendix B: Utility and Energy Data 33
Appendix C: Equipment Data 39
Appendix D: Abbreviations 44
Audit Team
The energy audit is performed by Alaska Energy Engineering LLC of Juneau, Alaska. The audit team
consists of:
Jim Rehfeldt, P.E., Energy Engineer
Jack Christiansen, Energy Consultant
Brad Campbell, Energy Auditor
Loras O’Toole P.E., Mechanical Engineer
Will Van Dyken P.E., Electrical Engineer
Curt Smit, P.E., Mechanical Engineer
Philip Iverson, Construction Estimator
Karla Hart, Technical Publications Specialist
Jill Carlile, Data Analyst
Grayson Carlile, Energy Modeler
Craig High School 1 Energy Audit (October 2011)
Section 1
Executive Summary
An energy audit of the Craig High School was performed by Alaska Energy Engineering LLC. The
investment grade audit was funded by Alaska Housing Finance Corporation (AHFC) to identify
opportunities to improve the energy performance of public buildings throughout Alaska.
Craig High School is a 52,219 square foot building that contains offices, classrooms, commons, a
library, a gym, an auditorium, a shop, and mechanical support spaces.
Building Assessment
The following summarizes our assessment of the building.
Envelope
The building ventilation and heating systems are designed to only work efficiently and effectively if
the building envelope is tightly sealed. The design and construction of the building envelope and the
rooftop ductwork penetrations have resulted in a very poorly sealed building. Significant energy
losses and operational concerns exist in the second floor fan room spaces and the unfinished second
floor space, including:
- An unused 20” diameter opening through the insulated roof on the northwest end of the
building for exhaust fan EF-8 which was never installed.
- A 6’ x 12’ uninsulated portion of the ceiling with a 1-1/2’ x 3’ opening at the peak of the
roof in the fan room adjacent to the auditorium.
- Insufficient plenum return openings for AHU-1 through the second floor on the south
side.
- Unsealed duct work penetrations through the roof of the building.
- The building design which utilizes a steel beam and corrugated roofing underlayment
adds to the difficulty of sealing the building envelope.
Improper roof penetration sealing around exhaust duct penetrations also raises a concern with
drawing exhaust from the restrooms back into the second floor space where it can mix with classroom
return air and then be redistributed throughout the classrooms by AHU-1.
Proper AHU-1 operation for the heating and ventilating of classroom spaces requires that the
unfinished second floor acts as a return plenum to move return air from the classrooms to AHU-1.
Outside air infiltration through the unnecessary rooftop openings combined with poor ductwork
sealing efforts causes mixing of the warm return air with colder outside air, thereby reducing the
return air temperature to AHU-1 and increasing the heating demand on the unit. Energy will be saved
if the building envelop leakage issues are corrected.
When AHU-1 is off and not pulling air from the second floor space, warm air from the second floor is
leaking through the unsealed roof penetrations. As the warm air passing through the openings cools, it
can condense within the roof penetration space and cause water damage above the corrugated roofing
base and below the roof insulation. This appears to be happening at multiple locations in the attic and
could reduce the life of the building envelope.
Craig High School 2 Energy Audit (October 2011)
AHU-1 supply and return air flows should be balanced and verified through retro-commissioning
once the building envelope is sealed to ensure efficient operations.
- The holes cut in the second story floor to provide an air path from the first floor return
plenum appear to be too small and may be requiring AHU-1 return fan to operate at an
increased electrical demand. Since the building envelope is excessively leaky, the
undersized plenum return openings cause more outside air to be being pulled into the
second floor space. This was quantified on the DDC by seeing a substantial drop in return
air temperature from the first floor to AHU-1, the result of which will increase the
heating demand of AHU-1. Larger floor openings will result in reduced flow restrictions
on the return air and thereby reduce heating loads of AHU-1 and should decrease the
electrical loading of AHU-1 return fan.
- The return air silencers in the fan room wall are also undersized, which is causing the
return fan to operate at higher speeds and energy consumption.
Exterior doors are not thermally broken. Future exterior door replacement selection should include
this feature. Weather stripping on exterior doors is in need of replacement throughout.
Some exterior wall shingles appeared to be damaged or missing as a result of recent building pressure
washing efforts.
The roof penetrations around MAU-1 in the shop space are not sealed. Air is flowing through the
unsealed opening and condensation is occurring.
Exhaust fans are being operated after the AHU’s turn off. This may be putting a negative pressure on
the spaces within the building envelope and compounding the outside air infiltration issues.
Several of the second floor exhaust fans were not installed and the remaining fans were not installed
properly on their concrete bases.
A fire sprinkler main passes directly through the center of the EF-6 discharge duct. This is reducing
fan efficiency and may be a code violation.
The gable awning over the south gym entrance does not have gutters. As a result the drainage path for
rainwater is along the wall and down the rock face. Damage may occur to the rock face and grouting
as a result.
On a positive note, there are very few windows in the north exterior wall and none in the east exterior
wall, thus reducing heat loss on walls that have minimal solar gain.
Heating System
The building is heated by two fuel oil boilers that provide heat to five air handling unit systems, a
make-up air unit in the shop, fan coil units, and perimeter hydronic systems. Maintenance staff are
very actively managing the boiler run times to minimize fuel consumption where possible due to
normal boiler inefficiencies. The boilers are currently being operated at 120°F in an effort to conserve
energy, however this will decrease the life of the stack and the temperature should be raised to the
normal operating band. Several of the boiler loop circulation pump motors have failed and have been
replaced with less efficient models. These should be upgraded to premium efficiency motors. The
remainder of the fuel oil boiler heating system appears to be in good condition; however fairly simple
improvements, outlined in Section 3, can be made to improve its effectiveness and efficiency.
Craig High School 3 Energy Audit (October 2011)
Ventilation System
The building ventilation systems consists of five large air handling units located in two interior fan
rooms and one make-up air roof top unit that provide conditioned air within the building envelope. In
addition to the large air handling units there are fifteen exhaust fans mounted throughout the building
and on the roof top for the purposes of cooling spaces, improving building air quality, kitchen
operations, and fume hood exhaust air flow in the science labs.
The building air handling units and the DDC system do not appear to have been properly
commissioned following construction.
The air handling unit that provides heating and ventilation for the classrooms was brought on-line
recently through efforts by maintenance staff and a DDC programmer. The remaining systems should
be corrected in a similar fashion and a retro-commissioning effort should be performed for the entire
building upon completion of repairs and right-sizing efforts for ventilation requirements.
Locker room air handling unit AHU-4 was turned off and under repair during the audit visit.
The AHU-5 fan belt shield is off and should be reinstalled.
The air handling units are considerably over-sized for Craig, Alaska. The sizing is more appropriate
for a warmer, sunny climate that operates through the summer and experiences high solar gain. The
air flows should be “right-sized” and the systems rebalanced to save energy.
Space Existing CFM/sqft Optimal CFM/sqft % Oversized
Auditorium 2.54 1.5 69%
Gym 1.72 1.1 56%
Commons 2.49 1.6 56%
Classrooms Varies 1.0 -
Given the oversized ventilation system, consolidation would further optimize air handling and reduce
energy costs. Whole-building optimization is beyond the scope of this energy audit but is
recommended if the ventilation EEMs are pursued.
Domestic Hot Water System
An oil-fired hot water heater supplies domestic hot water. When the heater reaches the end of its
service life, it is recommended to replace it with an indirect heater connected to the boiler heating
system and a smaller oil-fired heater for summer use when the boilers are off.
Lighting
Interior lighting primarily consists of T8 and metal halide lighting. Exterior lighting consists
primarily of metal halide lighting. The interior lighting schedule and all exterior lighting, including
parking lot lighting, is controlled by staff. As a result, lighting operational hours and subsequent
electrical demand is being kept to a minimum.
Craig High School 4 Energy Audit (October 2011)
Energy Efficiency Measures (EEMs)
All buildings have opportunities to improve their energy efficiency. The energy audit revealed
numerous opportunities in which an efficiency investment will result in a net reduction in long-term
operating costs.
Behavioral and Operational EEMs
The following EEMs require behavioral and operational changes in the building use. The savings are
not readily quantifiable but these EEMs are highly recommended as low-cost opportunities that are a
standard of high performance buildings.
EEM-1: Weather-strip Doors
EEM-2: Adjust Double Door Closures
EEM-3: Repair Window Weather Stripping
EEM-4: Replace Failed Window Glazing
EEM-5: Seal Building Envelope
EEM-6: Server Room Heat Recovery
High and Medium Priority EEMs
The following EEMs are recommended for investment. They are ranked by life cycle savings to
investment ratio (SIR). This ranking method places a priority on low cost EEMs which can be
immediately funded, generating energy savings to fund higher cost EEMs in the following years.
Negative values, in parenthesis, represent savings.
25 Year Life Cycle Cost Analysis
Investment Operating Energy Total SIR
High Priority
EEM-7: Turn Off Standby Boiler $200 $0 ($78,700) ($78,500) 393.5
EEM-8: Install Pipe Insulation $900 $0 ($46,000) ($45,100) 51.1
EEM-9: Replace Aerators $1,400 $0 ($67,400) ($66,000) 48.1
EEM-10: Perform Boiler Combustion Test $700 $4,600 ($21,200) ($15,900) 23.7
EEM-11: Upgrade Motors to Premium Efficiency $2,700 $0 ($9,400) ($6,700) 3.5
Medium Priority
EEM-12: Optimize Gym AHU-5 $55,000 $0 ($166,600) ($111,600) 3.0
EEM-13: Upgrade Transformer $23,600 $0 ($68,100) ($44,500) 2.9
EEM-14: Replace Exit Signs $3,300 ($1,300) ($7,100) ($5,100) 2.5
EEM-15: Increase AHU-1 Return Air Path $4,000 $0 ($10,000) ($6,000) 2.5
EEM16-: Install Valves on Unit Heaters $4,400 $0 ($9,500) ($5,100) 2.2
EEM-17: Install Modulating Boiler Burners $33,700 $15,400 ($84,600) ($35,500) 2.1
EEM-18: Optimize Auditorium AHU-3 $62,800 $0 ($124,100) ($61,300) 2.0
EEM-19: Optimize Heating System $90,600 ($15,400) ($154,800) ($79,600) 1.9
EEM-20: Optimize Commons AHU-4 $59,700 $0 ($98,200) ($38,500) 1.6
EEM-21: Install Boiler Room Heat Recovery $23,100 $4,600 ($41,500) ($13,800) 1.6
EEM-22: Reduce Locker Room Lighting $7,100 ($600) ($8,600) ($2,100) 1.3
Totals* $373,200 $7,300 ($995,800) ($615,300) 2.6
Craig High School 5 Energy Audit (October 2011)
* The analysis is based on each EEM being independent of the others. While it is likely that some
EEMs are interrelated, an isolated analysis is used to demonstrate the economics because the audit
team is not able to predict which EEMs an Owner may choose to implement. If several EEMs are
implemented, the resulting energy savings is likely to differ from the sum of each EEM projection.
Summary
It is the assessment of the energy audit team that the Craig High School staff are very focused on
lowering energy consumption at the facility in their daily operations. Unfortunately, energy efficiency
is unattainable due to a substandard building envelope and oversized air handling units that are
operating with non-optimal control sequences that were not properly commissioned. This has resulted
in a situation that cannot be corrected by operational modifications alone.
Outlined within the report are recommendations for building envelope sealing efforts, modifications
to the air handling systems and control sequences, and subsequent building retro-commissioning. The
energy audit revealed other opportunities for improving the energy performance of the Craig High
School as well. It is recommended that the behavioral and high priority EEMs be implemented now to
generate energy savings from which to fund the medium priority EEMs.
Another avenue to consider is to borrow money from AHFCs revolving loan fund for public
buildings. AHFC will loan money for energy improvements under terms that allow for paying back
the money from the energy savings. More information on this option can be found online at
http://www.ahfc.us/loans/akeerlf_loan.cfm.
Craig High School 6 Energy Audit (October 2011)
Section 2
Introduction
This report presents the findings of an energy audit of Craig High School located in Craig, Alaska.
The purpose of this investment grade energy audit is to evaluate the infrastructure and its subsequent
energy performance to identify applicable energy efficiencies measures (EEMs).
The energy audit report contains the following sections:
Introduction: Building use and energy consumption.
Energy Efficiency Measures: Priority ranking of the EEMs with a description, energy analysis,
and life cycle cost analysis.
Description of Systems: Background description of the building energy systems.
Methodology: Basis for how construction and maintenance cost estimates are derived and the
economic and energy factors used for the analysis.
BUILDING USE
Craig High School is a 52,219 square foot building that contains offices, classrooms, commons, a
library, a gym, an auditorium, a shop, and mechanical support spaces. The building is occupied by 95
students and 10 staff members. It is used in the following manner:
Offices and Classrooms: 7:30 am – 3:30 pm (M-F)
Commons: 7:00 am – 10:00 pm (M-F), 3:00pm – 9:00pm (S-Su)
Gym 8:00 am – 10:00 pm (M-F) ), 3:00pm – 9:00pm (S-Su)
Auditorium 12:00 pm – 3:00 pm (M-F)
Fans: 7:30 am – 4:00 pm (M-F)
History
This building was constructed in 2000.
Energy Consumption
The building energy sources include an electric service and a fuel oil tank. Fuel oil is used for the
majority of the heating loads while electricity serves all other loads, including domestic hot water and
a limited amount of space heating. The following table shows annual energy use and cost.
Annual Energy Consumption and Cost
Source Consumption Cost Energy,
MMBtu
Electricity 259,880 kWh $69,100 890 27%
Fuel Oil 18,100 Gallons $61,900 2,460 73%
Totals - $131,000 3,350 100%
Craig High School 7 Energy Audit (October 2011)
Electricity
This chart shows electrical
energy use from 2007 to
2010.
Use has been fairly
consistent over the last
four years.
The effective cost—energy
costs plus demand
charges—is 26.6¢ per
kWh.
Fuel Oil
This chart shows heating
energy use from 2007 to
2010.
The chart compares annual
use with the heating degree
days which is a
measurement of the
demand for energy to heat
a building. A year with a
higher number of degree
days reflects colder outside
temperatures and a higher
heating requirement.
Fuel oil use dropped in 2010 due to lower heating degree days and efforts by operating staff to reduce
energy consumption. Fuel oil use is likely to increase in 2011 due to bringing AHU-1 into service.
The current cost of fuel oil in Craig is $3.89 per gallon. Assuming a fuel oil conversion
efficiency of 70%, oil heat costs $40.12 per MMBtu. The current cost of electricity is
26.6¢ per kWh. Assuming an electric conversion efficiency of 95%, electric heat costs
$82.00 per MMBtu. As such, fuel oil heat is much less expensive than electric heat.
Craig High School 8 Energy Audit (October 2011)
Section 3
Energy Efficiency Measures
The following energy efficiency measures (EEMs) were identified during the energy audit. The
EEMs are priority ranked and, where applicable, subjected to energy and life cycle cost analysis.
Appendix B contains the energy and life cycle cost analysis spreadsheets.
The EEMs will be grouped into the following prioritized categories:
Behavioral or Operational: EEMs that require minimal capital investment but require operational
or behavioral changes. The EEMs provide a life cycle savings but an analysis is not performed
because the guaranteed energy savings is difficult quantify.
High Priority: EEMs that require a small capital investment and offer a life cycle savings. Also
included in this category are higher cost EEMs that offer significant life cycle savings.
Medium Priority: EEMs that require a significant capital investment to provide a life cycle
savings. Many medium priority EEMs provide a high life cycle savings and offer substantial
incentive to increase investment in building energy efficiency.
Low Priority: EEMs that will save energy but do not provide a life cycle savings.
BEHAVIORAL OR OPERATIONAL
The following EEMs are recommended for implementation. They require behavioral or operational
changes that can occur with minimal investment to achieve immediate savings. These EEMs are not
easily quantified by analysis because they cannot be accurately predicted. They are recommended
because they offer a life cycle savings, represent good practice, and are accepted features of high
performance buildings.
EEM-1: Weather-strip Doors
Purpose: The weather stripping on most of the singe-wide exterior doors is in poor condition and
the double-door weather stripping system on the center support bars is ineffective.
Energy will be saved if doors are properly weather-stripped to reduce infiltration.
Scope: Replace weather stripping on exterior doors.
EEM-2: Adjust Double Door Closures
Purpose: The front doors are not completely closing due to weather stripping interference and
improper door closure adjustment. Energy would be saved if the automatic closures are
properly adjusted following the repair or replacement of the weather stripping to ensure
complete door sealing.
Scope: Repair or replace weather stripping and adjust double-door automatic closures for
proper sealing.
Craig High School 9 Energy Audit (October 2011)
EEM-3: Repair Window Weather Stripping
Purpose: Weather stripping has been obviously damaged on several of the operable windows.
Energy will be saved if all of the operable windows are fully opened to inspect weather
stripping and repairs are made as needed.
Scope: Inspect and repair operable window weather stripping.
EEM-4: Replace Failed Window Glazing
Purpose: The glazing has failed on the upper section of a window on the north wall of the
northwest classroom. Energy will be saved if the failed glazing is replaced.
Scope: Replace failed glazing section.
EEM-5: Seal Building Envelope
Purpose: The design and construction of the building envelope and the rooftop ductwork
penetrations have resulted in a very poorly sealed building. Significant energy losses
and operational concerns exist in the second floor fan room spaces and the unfinished
second floor space as outlined in the Executive Summery. Energy will be saved and
building longevity may be increased if these discrepancies are repaired
Scope: Perform the following envelope repairs:
i. Seal and insulate the 20” diameter opening through the insulated roof on the
northwest end of the building where exhaust fan EF-8 was supposed to be
installed.
ii. Seal and insulate the 6’ x 12’ uninsulated portion of the ceiling, to include the
1½’ x 3’ opening at the peak of the roof in the main air handler unit space above
the auditorium
iii. Seal all duct work penetrations through the roof of the building.
EEM-6: Server Room Heat Recovery
Purpose: The server room contains 3 switches, 1 server, some additional heat generating
electrical equipment, and also has heat gain through the floor. Maintenance staff
informed the audit team that this space gets too warm. Energy will be saved if the
additional heat in this space is delivered to AHU-1 in the adjacent space for
recirculation through the school.
Scope: Install a grill in the south and north walls of the server space so that second floor
plenum return air can be transferred to AHU-1 through the server room.
Craig High School 10 Energy Audit (October 2011)
HIGH PRIORITY
The following EEMs are recommended for implementation because they are low cost measures that
have a high savings to investment ratio. The EEMs are listed from highest to lowest priority. Negative
values, in parenthesis, represent savings.
EEM-7: Turn off Standby Boiler
Purpose: Only one boiler is required to meet the heating load, yet both are operated and kept
warm. Energy will be saved by closing the valve in the return main, thus isolating the
standby boiler.
Scope: Close the valve on the return main and shut off the standby boiler.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($2,780) ($2,780) $200 $0 ($78,700) ($78,500) 393.5
EEM-8: Install Pipe Insulation
Purpose: An 8’ section of 6” pipe, a 12’ section of 4” pipe, and a 12’ section of 2 ½” pipe, all on
the boiler system expansion U-bends in the second floor space, are uninsulated. Energy
will be saved if these sections of boiler supply and return piping are optimally
insulated.
Scope: Install insulation on uninsulated boiler supply and return piping.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,620) ($1,620) $900 $0 ($46,000) ($45,100) 51.1
EEM-9: Replace Aerators
Purpose: Energy and water will be saved by replacing the aerators on the lavatories and
showerheads with low-flow models.
Scope: Replace aerators on lavatories and showerheads with water-conserving fixtures.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($3,430) ($3,430) $1,400 $0 ($67,400) ($66,000) 48.1
EEM-10: Perform Boiler Combustion Test
Purpose: Operating the boiler with an optimum amount of excess air will improve combustion
efficiency. Annual cleaning followed by a combustion test is recommended.
Scope: Annually clean and perform a combustion test on the boiler.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$240 ($750) ($510) $700 $4,600 ($21,200) ($15,900) 23.7
Craig High School 11 Energy Audit (October 2011)
EEM-11: Upgrade Motors to Premium Efficiency
Purpose: Premium efficiency motors should be used for equipment that operates during school
hours. A motor efficiency of 60 % is low enough to warrant replacement before a
motor fails. Energy will be saved if pump P-4B and P-7 motors and the AHU-2 return
fan motor are all replaced with premium efficiency motors.
Scope: Replace pump P-4B and P-7 motors and AHU-2 return fan motor with premium
efficiency motors.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($480) ($480) $2,700 $0 ($9,400) ($6,700) 3.5
MEDIUM PRIORITY
Medium priority EEMs require planning and a higher level of investment. They are recommended
because they offer a life cycle savings. The EEMs are listed from highest to lowest priority. Negative
values, in parenthesis, are savings.
EEM-12: Optimize Gym AHU-5
Purpose: The gym AHU-5 is oversized by a factor of 56%, consuming additional energy to run
the fan. In addition, the unit supplies more outside air than required, which results in
higher heating demands. Energy will be saved if the system controls are optimized.
Scope: Perform the following control modifications and retro-commission:
i. Install a variable speed drive on the supply fan to reduce air flow and modulate
air flow with cooling loads.
ii. Add a CO2 sensor to control and reduce outside air flow while maintaining
adequate indoor air quality.
iii. Reset the supply air temperature with gym temperature.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($6,620) ($6,620) $55,000 $0 ($166,600) ($111,600) 3.0
EEM-13: Replace Transformer
Purpose: The 150 kVA transformer in electrical room 137 is not TP-1 rated. Energy will be
saved if this less-efficient transformer is replaced with an energy efficient model that
complies with NEMA Standard TP 1-2001.
Scope: Replace less-efficient transformer with a NEMA Standard TP 1-2001compiant model.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($3,470) ($3,470) $23,600 $0 ($68,100) ($44,500) 2.9
Craig High School 12 Energy Audit (October 2011)
EEM-14: Replace Exit Signs
Purpose: The exit signs utilize two 7.7 watt tungsten bulbs. Energy will be saved if the exit signs
are replaced with self-luminescent signs.
Scope: Replace the eleven existing exit signs with self-luminescent exit signs.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($70) ($360) ($430) $3,300 ($1,300) ($7,100) ($5,100) 2.5
EEM-15: Increase AHU-1 Return Air Path
Purpose: The return air path for AHU-1 travels through holes in the floor deck above and
silencers in the wall of the fan room. The free area of these openings is too small,
which is creating high pressure loss and causing the return fan to work harder to pull
the air back to AHU-1. This is also causing outside air to be pulled into the building
through the leaky envelope. Energy will be saved, and the building pressure will be
better regulated, if the return air path openings are increased in size.
Scope: Double the size of the return air floor openings. Remove the silencers and double the
size of the wall openings.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($510) ($510) $4,000 $0 ($10,000) ($6,000) 2.5
EEM-16: Install Automatic Valves on Unit Heaters
Purpose: Energy will be saved if the seven wall and ceiling mounted unit heaters have an
automatic valve that shuts off the heating flow when heat is not needed. Currently the
coils in the unit heaters are continuously hot and the thermostat turns on the fan to
supply the heat to the room. When heat is not needed, convective heat loss from the
coil occurs; some of the heat loss may be useful, but a large percentage is not.
Scope: Install automatic valves in the heating supply to each unit heater and control them from
the fan thermostat.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($330) ($330) $4,400 $0 ($9,500) ($5,100) 2.2
EEM-17: Install Modulating Boiler Burners
Purpose: The boiler burners do not incorporate modulating burner controls. Energy will be saved
if the boiler firing rate modulated as necessary.
Scope: Install modulating burners on the boilers.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$800 ($2,990) ($2,190) $33,700 $15,400 ($84,600) ($35,500) 2.1
Craig High School 13 Energy Audit (October 2011)
EEM-18: Optimize Auditorium AHU-3
Purpose: The auditorium AHU-3 is currently operated from 7:30 am to 4:00 pm. However, the
auditorium is only used for classes from 12:00 pm to 3:00 pm.
AHU-3 is oversized by a factor of 69%, consuming additional energy to run the fan. In
addition, the unit supplies more outside air than required, which results in higher
heating demands. Energy will be saved if the system controls are optimized.
Scope: Perform the following control modifications and retro-commission AHU-3:
i. Install a variable speed drive on the supply and return fans to reduce air flow
and modulate air flow with cooling loads.
ii. Add a CO2 sensor to control and reduce outside air flow while maintaining
adequate indoor air quality.
iii. Reset the cold deck temperature with auditorium temperature.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($5,420) ($5,420) $62,800 $0 ($124,100) ($61,300) 2.0
EEM-19: Optimize Heating System
Purpose: The heating system has a capacity of 150 Btuh/sqft which is five times larger than
typical for a school building. A heating system optimization analysis is needed to right-
size the system and increase its efficiency. Opportunities include reducing the size of
the boilers by removing sections and combining the distribution loops into one set of
pumps.
Scope: Optimize the heating system by recalculating the building heating loads, reducing
boiler size and serving the distribution loops into one set of pumps. This should be
performed after the AHU EEMs have been implemented, which will reduce heating
loads.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($800) ($6,410) ($7,210) $90,600 ($15,400) ($154,800) ($79,600) 1.9
Craig High School 14 Energy Audit (October 2011)
EEM-20: Optimize Commons AHU-2
Purpose: The Commons AHU-2 is oversized by a factor of 56%, consuming additional energy to
run the fan. In addition, the unit supplies more outside air than required, which results
in higher heating demands. Energy will be saved if the system controls are optimized.
Scope: Perform the following control modifications and retro-commission:
i. Install a variable speed drive on the supply and return fans to reduce and
modulate air flow with cooling loads.
ii. Add a CO2 sensor to control and reduce outside air flow while maintaining
adequate indoor air quality.
iii. Reset the supply air temperature with commons temperature.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($4,060) ($4,060) $59,700 $0 ($98,200) ($38,500) 1.6
EEM-21: Install Boiler Room Heat Recovery
Purpose: The boiler room uses inlet and outlet grills to exhaust air outside the space. Energy will
be saved if the heat generated from the boiler room is transferred to the adjacent shop
room.
Scope: Install a heat recovery unit to transfer boiler room heat to the adjacent shop space.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$240 ($900) ($660) $23,100 $4,600 ($41,500) ($13,800) 1.6
EEM-22: Reduce Locker Room Lighting
Purpose: Lighting controls for the gym locker rooms are by key switch-only. This requires the
space to be lit throughout the entire period the gym is open, regardless of use. Energy
will be saved if a motion detector is installed in the shower space and another in the
restroom space to minimize unnecessary lighting hours. A 10-minute delay time is
recommended for the occupancy sensor.
Scope: Install a motion detector in the shower space and in the restroom space to control
locker room lighting.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($30) ($530) ($560) $7,100 ($600) ($8,600) ($2,100) 1.3
Craig High School 15 Energy Audit (October 2011)
LOW PRIORITY
Low priority EEMs do not offer a life cycle energy savings and are not recommended.
EEM-23: Add Arctic Entry
Purpose: A significant amount of infiltration and heat loss is occurring because the main
entrance does not have an arctic entry. The existing design lends itself well to this
addition without compromising building aesthetics.
Scope: Install an arctic entry.
Analysis: Previous analyses have shown that an arctic entrance is cost effective for new
construction. However, adding an arctic entrance is not cost effective for this retro-fit
application.
Craig High School 16 Energy Audit (October 2011)
Section 4
Description of Systems
ENERGY SYSTEMS
This section provides a general description of the building systems. Energy conservation
opportunities are addressed in Section 3, Energy Efficiency Measures.
Building Envelope
The following table summarizes the existing envelope.
Building Envelope
R-value
Component Description (inside to outside) Existing Optimal
Exterior Wall 1/2” Gyp. Bd, 1” Rmax, 6” steel studs w/ R-19 batt, ½” plywood R-16 R-26
Roof Corrugated Metal Roof Deck, 8” EPS rigid insulation, metal roofing R-34 R-46
Floor Slab 4” Concrete slab-on-grade R-15 R-10
Foundation 8” concrete with 2” rigid insulation on interior surface R-10 R-20
Windows Fiberglass; double pane R-1.5 R-5
Doors Aluminum along the front entry, remaining doors are steel, all
w/o thermal break, glazing where used is double pane R-1.5 R-5
Domestic Hot Water System
An oil fired direct hot water heater supplies domestic hot water to the fixtures. The fixtures do not
have water-conserving aerators.
Automatic Control System
The building has a DDC system to control the operation of the heating and ventilation systems,
however the systems do not appear to have been properly installed and commissioned following
construction. It is recommended that the maintenance staff continue working with DDC programming
support to improve heating and ventilation control capabilities as outlined in this report.
Lighting
Interior lighting primarily consists of T8 and metal halide lighting. Exterior lighting consists
primarily of metal halide lighting. The interior lighting schedule and all exterior lighting - to include
the parking lot lighting, is controlled by staff. Thanks to staff diligence, lighting operational hours and
subsequent electrical demand are kept to a minimum.
Electric Equipment
Commercial kitchen equipment for food preparation is located in the food prep area.
Craig High School 17 Energy Audit (October 2011)
Heating System
The building is heated by two fuel oil boilers that provide heat to five air handling unit systems, a
make-up air unit in the shop, unit heaters, and perimeter hydronic systems. The heating system has
the following pumps:
P-1A and P-1B are the circulation pumps for boilers 1 and 2.
P-2 is the domestic hot water circulation pump.
P-3A and P-3B are the perimeter heat pumps.
P-4A and P-4B are the shop heating pumps.
P-5A and P-5B are the AHU supply heating coil pumps.
P-6 is the MAU-1 heating coil pump.
P-7 is the AHU-1 heating coil pump.
P-8 is the AHU-2 pre-heating coil pump.
P-9 is the AHU-2 heating coil pump.
P-10 is the AHU-3 preheat coil pump.
P-11 is the AHU-3 hot deck coil pump.
P-12 is the AHU-4 heating coil pump.
P-13 is the AHU-5 heating coil pump.
Craig High School 18 Energy Audit (October 2011)
Ventilation Systems
Area Fan System Description
Classrooms AHU-1 Variable volume air handling unit consisting of a heating coil, mixing
box, filter section, supply fan, and return air fan
Commons Area AHU-2 Constant volume air handling unit consisting of a pre-heating coil,
heating coil, mixing box, filter section, supply fan, and return air fan
Auditorium AHU-3 Constant volume air handling unit consisting of a pre-heating coil,
heating coil, mixing box, filter section, supply fan, and return air fan
Locker Room AHU-4 Constant volume air handling unit consisting of a heating coil, mixing
box, filter section, and a supply fan
Gymnasium AHU-5 Constant volume air handling unit consisting of a heating coil, mixing
box, filter section, supply fan, and return air fan
Shop MAU-1 3,680 cfm 3 HP constant volume make up air fan
Rest Room/Janitor EF-1 1,420 cfm 755 watt constant volume in-line cabinet exhaust fan
Locker Room EF-2 1,515 cfm 1/3 HP constant volume backward inclined centrifugal
exhaust fan
Kitchen EF-3 190 cfm constant volume kitchen exhaust hood
Art Classroom EF-4 1,680 cfm ½ HP constant volume belt drive roof exhauster
Restroom EF-5 100 cfm 80 W ceiling exhaust fan
Science Classroom EF-6 4,190 cfm ¾ HP constant volume backward inclined centrifugal
exhaust fan
Science Room Fume Hood EF-7 1,200 cfm 1/3 HP constant volume belt drive roof exhauster
Math Classroom EF-8 1,500 cfm ¼ HP constant volume backward inclined centrifugal
exhaust fan (Not Installed)
Home Ec Classroom EF-9 1,970 cfm 1/3 HP constant volume backward inclined centrifugal
exhaust fan
Home Ec Cooktop Exhaust EF-10 190 cfm kitchen hood exhaust
Home Ec Cooktop Exhaust EF-11 190 cfm kitchen hood exhaust
Home Ec Cooktop Exhaust EF-12 190 cfm kitchen hood exhaust
Home Ec Cooktop Exhaust EF-13 190 cfm kitchen hood exhaust
Pressbox EF-14 250 cfm 83 watt inline cabinet exhaust fan
Science/Prep General Exhaust EF-15 750 cfm ¼ HP constant volume backward inclined centrifugal exhaust
fan
Welding Exhaust Fan CS-1 1800 cfm 1.5 HP constant volume backward inclined centrifugal
exhaust fan
Weld Station Hood CS-2 800 cfm vertical hood
Vehicle Exhaust System CS-3 850 cfm ¾ HP constant volume backward inclined centrifugal exhaust
fan
Craig High School 19 Energy Audit (October 2011)
Section 5
Methodology
Information for the energy audit was gathered through on-site observations, review of construction
documents, and interviews with operation and maintenance personnel. The EEMs are evaluated using
energy and life cycle cost analyses and are priority ranked for implementation.
Energy Efficiency Measures
Energy efficiency measures are identified by evaluating the building’s energy systems and comparing
them to systems in modern, high performance buildings. The process for identifying the EEMs
acknowledges the realities of an existing building that was constructed when energy costs were much
lower. Many of the opportunities used in modern high performance buildings—highly insulated
envelopes, variable capacity mechanical systems, heat pumps, daylighting, lighting controls, etc.—
simply cannot be economically incorporated into an existing building.
The EEMs represent practical measures to improve the energy efficiency of the buildings, taking into
account the realities of limited budgets. If a future major renovation project occurs, additional EEMs
common to high performance buildings should be incorporated.
Life Cycle Cost Analysis
The EEMs are evaluated using life cycle cost analysis which determines if an energy efficiency
investment will provide a savings over a 25-year life. The analysis incorporates construction,
replacement, maintenance, repair, and energy costs to determine the total cost over the life of the
EEM. Future maintenance and energy cash flows are discounted to present worth using escalation
factors for general inflation, energy inflation, and the value of money. The methodology is based on
the National Institute of Standards and Technology (NIST) Handbook 135 – Life Cycle Cost
Analysis.
Life cycle cost analysis is preferred to simple payback for facilities that have long—often perpetual—
service lives. Simple payback, which compares construction cost and present energy cost, is
reasonable for short time periods of 2-4 years, but yields below optimal results over longer periods
because it does not properly account for the time value of money or inflationary effects on operating
budgets. Accounting for energy inflation and the time value of money properly sums the true cost of
facility ownership and seeks to minimize the life cycle cost.
Construction Costs
The cost estimates are derived based on a preliminary understanding of the scope of each EEM as
gathered during the walk-through audit. The construction costs for in-house labor are $60 per hour for
work typically performed by maintenance staff and $110 per hour for contract labor.
The cost estimate assumes the work will be performed as part of a larger renovation or energy
efficiency upgrade project. When implementing EEMs, the cost estimate should be revisited once the
scope and preferred method of performing the work has been determined. It is possible some EEMs
will not provide a life cycle savings when the scope is finalized.
Craig High School 20 Energy Audit (October 2011)
Maintenance Costs
Maintenance costs are based on in-house or contract labor using historical maintenance efforts and
industry standards. Maintenance costs over the 25-year life of each EEM are included in the life cycle
cost calculation spreadsheets and represent the level of effort to maintain the systems.
Energy Analysis
The energy performance of an EEM is evaluated within the operating parameters of the building. A
comprehensive energy audit would rely on a computer model of the building to integrate building
energy systems and evaluate the energy savings of each EEM. This investment grade audit does not
utilize a computer model, so energy savings are calculated with factors that account for the dynamic
operation of the building. Energy savings and costs are estimated for the 25-year life of the EEM
using appropriate factors for energy inflation.
Prioritization
Each EEM is prioritized based on the life cycle savings to investment ratio (SIR) using the following
formula:
Prioritization Factor = Life Cycle Savings / Capital Costs
This approach factor puts significant weight on the capital cost of an EEM, making lower cost EEMs
more favorable.
Economic Factors
The following economic factors are significant to the findings.
Nominal Interest Rate: This is the nominal rate of return on an investment without regard to
inflation. The analysis uses a rate of 5%.
Inflation Rate: This is the average inflationary change in prices over time. The analysis uses an
inflation rate of 2%.
Economic Period: The analysis is based on a 25-year economic period with construction
beginning in 2010.
Fuel Oil
Fuel oil currently costs $3.42 per gallon for a seasonally adjusted blend of #1 and #2 fuel oil. The
analysis is based on 6% fuel oil inflation which has been the average for the past 20-years.
Electricity
Electricity is supplied by Alaska Power and Telephone. The building is billed for electricity under
Alaska Power Company Bulk Power A-3 rate. This rate charges for both electrical consumption
(kWh) and peak electric demand (kW). Electrical consumption is the amount of energy consumed and
electric demand is the rate of consumption.
Alaska Power Company Bulk Power A-3 Rate
Electricity ($ / kWh ) $0.0786
Cost of Power Adjustment ($ / kWh) $0.1534
Demand ( $ / kW ) $7.00
Customer Charge ( $ / mo. ) $140.86
Craig High School 21 Energy Audit (October 2011)
Summary
The following table summarizes the energy and economic factors used in the analysis.
Summary of Economic and Energy Factors
Factor Rate or Cost Factor Rate or Cost
Nominal Discount Rate 5% Electricity $0.274/kwh
General Inflation Rate 2% Electricity Inflation 3%
Fuel Oil Cost (2012) $4.12/gal Fuel Oil Inflation 6%
Craig High School 22 Energy Audit (October 2011)
Appendix A
Energy and Life Cycle Cost Analysis
Craig High School 23 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
Basis
Economic
Study Period (years) 25 Nominal Discount Rate 5%General Inflation 3%
Energy
2011 $/gal Fuel Inflation 2012 $/gal
Fuel Oil $3.89 6% $4.12
Electricity $/kWh (2011)$/kW (2011)Inflation $/kWh (2012)$/kW (2012)
w/ Demand Charges $0.232 $7.00 3% $0.239 $7.21
w/o Demand Charges $0.266 -3% $0.274 -
EEM-7: Turn Off Standby Boiler
Energy Analysis
Boiler Input MBH Loss %Loss MBH Hours, exist Hours, new kBtu η boiler Gallons
B-1 3,893 0.50% 19 5,760 2,500 -63,454 68%-674
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Stage boiler operation 0 2 ea $100 $200
Annual Costs
Manually sequence lead/standby boilers 1 - 25 $60.00 $0
Energy Costs
Fuel Oil 1 - 25 -674 gal $4.12 ($78,745)
Net Present Worth ($78,500)
EEM-8: Install Pipe Insulation
Energy Analysis
Service Size Length Bare BTUH Insul BTUH Factor kBtu η boiler Gallons
Heating 2.50 12 221 19 50% -10,617 68%-113
Heating 4.00 12 279 23 50% -13,455 68%-143
Heating 6.00 8 402 30 50% -13,035 68%-138
-394
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Pipe Insulation 2-1/2"0 12 lnft $13 $156
4"0 12 lnft $17 $204
6"0 8 lnft $20 $160
Estimating contingency 0 15%$78
Overhead & profit 0 30%$179
Design fees 0 10%$78
Project management 0 8%$68
Energy Costs
Fuel Oil 1 - 25 -394 gal $4.12 ($46,050)
Net Present Worth ($45,100)
Craig High School 24 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-9: Replace Aerators
Energy Analysis
Fixture Existing Proposed Uses/day Days Water,Gals % HW kBTU kWh
Showerhead 20.0 10.0 30.0 180 -54,000 80% -28,823 -8,448
Lavatories 0.3 0.2 300 180 -9,720 80% -5,188 -1,521
-63,720 -9,968
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace lavatory aerators 0 19 ea $35 $665
Replace showerhead 0 22 ea $35 $770
Energy Costs
Water 1 - 25 -64 kgals $10.960 ($13,728)
Electric Energy (Effective Cost)1 - 25 -9,968 kWh $0.274 ($53,686)
Net Present Worth ($66,000)
EEM-10: Perform Boiler Combustion Test
Energy Analysis
Annual Gal % Savings Savings, Gal
18,100 -1.0% -181
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Purchase combustion analyzer 0 1 LS $700 $700
Annual Costs
Combustion test 1 - 25 4 hrs $60.00 $4,628
Energy Costs
Fuel Oil 1 - 25 -181 gal $4.12 ($21,155)
Net Present Worth ($15,800)
EEM-11: Upgrade Motors to Premium Efficiency
Energy Analysis
Number HP ηold ηnew kW Hours kWh
2 0.33 60.0% 77.0% -0.08 1,530 -128
1 3 80.5% 89.5% -0.20 8,760 -1,764
-0.3 -1,893
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs HP
Replace motor 0.33 0 2 LS 550 $1,100
Replace motor 3 0 1 LS 1,080 $1,080
Estimating contingency 0 25%$545
Energy Costs
Electric Energy 1 - 25 -1,893 kWh $0.239 ($8,890)
Electric Demand 1 - 25 -3 kW $7.21 ($485)
Net Present Worth ($6,600)
Gallons per Use
Craig High School 25 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-12: Optimize Gym AHU-5
Energy Analysis
Ventilation Savings
Case SA CFM % OSA OSA CFM ΔT Hours kBtu η boiler Gallons
Existing -19,300 10% -1,930 30 1,530 -95,674 68%-1,016
New 11,000 5% 550 30 1,530 27,265 68%289
-1,380 -726
Fan Savings
Case CFM ΔP η, fan BHP η, motor kW Hours kWh
Existing -19,300 2.0 50% -12.1 91.7% -9.9 1,530 -15,118
New 11,000 1.5 50% 5.2 91.7% 4.2 1,530 6,462
-5.7 -8,656
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install SF VFD 0 1 LS $15,000 $15,000
Control modifications - CO2 sensor, revise sequence 0 1 LS $15,000 $15,000
Commissioning 0 1 LS $5,000 $5,000
Estimating contingency 0 15%$5,250
Overhead & profit 0 15%$6,038
Design fees 0 10%$4,629
Project management 0 8%$4,073
Energy Costs
Electric Energy 1 - 25 -8,656 kWh $0.239 ($40,659)
Electric Demand 1 - 25 -51 kW $7.21 ($7,216)
Fuel Oil 1 - 25 -1,016 gal $4.12 ($118,730)
Net Present Worth ($111,600)
EEM-13: Upgrade Transformer
Energy Analysis
Location kVA ηold ηnew KW kWh
150 97.8% 98.9% -1.65 -14,454
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace transformer, kVA 150 0 1 LS $15,300 $15,300
Overhead & profit 0 30%$4,590
Design fees 0 10%$1,989
Project management 0 8%$1,750
Energy Costs
Electric Energy 1 - 25 -14,454 kWh $0.239 ($67,896)
Electric Demand 1 - 25 -1.7 kW $7.21 ($234)
Net Present Worth ($44,500)
Craig High School 26 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-14: Replace Exit Signs
Energy Analysis
Number Watts, exist Watts,new kW kWh
11 15 0 -0.2 -1,445
Lamp Replacement
# Fixtures # Lamps Life, hrs Lamps//yr $/lamp Labor/lamp
11 -2 20,000 -10 $2 $5.00
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace exit light 0 11 LS $300 $3,300
Annual Costs
Lamp replacement 1 - 25 -10 $7.00 ($1,301)
Energy Costs
Electric Energy 1 - 25 -1,445 kWh $0.239 ($6,790)
Electric Demand 1 - 25 -2 kW $7.21 ($281)
Net Present Worth ($5,100)
EEM-15: Increase AHU-1 Return Air Path
Energy Analysis
Fan Savings
Case CFM ΔP η, fan BHP η, motor kW Hours kWh
Existing 12,000 -2.0 55% -6.9 91.7% -5.6 1,530 -8,545
New 12,000 1.5 55% 5.1 91.7% 4.2 1,530 6,409
-1.4 -2,136
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Increase ceiling openings 0 1 LS $2,000 $2,000
Remove silensers; increase wall openings 0 1 LS $2,000 $2,000
Energy Costs
Electric Energy 1 - 25 -2,136 kWh $0.239 ($10,035)
Net Present Worth ($6,000)
EEM16-: Install Valves on Unit Heaters
Energy Analysis
Loss, BTUH Number Factor Loss, kBTU Boiler Effic Fuel, gals
-1,250 7 10% -7,665 70% -81
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install automatic valves and connect to fan wiring 0 7 ea $350 $2,450
Estimating contingency 0 15%$368
Overhead & profit 0 30%$845
Design fees 0 10%$366
Project management 0 8%$322
Energy Costs
Fuel Oil 1 - 25 -81 gal $4.12 ($9,480)
Net Present Worth ($5,100)
Craig High School 27 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-17: Install Modulating Boiler Burners
Energy Analysis
Annual Gal % Savings Savings, Gal
18,100 -4.0% -724
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install modulating burner 0 2 LS $9,500 $19,000
Estimating contingency 0 15%$2,850
Overhead & profit 0 30%$6,555
Design fees 0 10%$2,841
Project management 0 8%$2,500
Annual Costs
Burner maintenance 1 - 25 2 LS $400.00 $15,427
Energy Costs
Fuel Oil 1 - 25 -724 gal $4.12 ($84,618)
Net Present Worth ($35,400)
EEM-18: Optimize Auditorium AHU-3
Energy Analysis
Ventilation Savings
Case SA CFM % OSA OSA CFM ΔT Hours kBtu η boiler Gallons
Existing -13,100 10% -1,310 30 1,530 -64,939 68%-690
New 8,000 10% 800 30 720 18,662 68%198
-510 -491
Fan Savings
Case CFM ΔP η, fan BHP η, motor kW Hours kWh
SF, exist -13,100 2.0 50% -8.2 91.7% -6.7 1,530 -10,261
SF, new 8,000 1.5 50% 3.8 91.7% 3.1 720 2,212
RF, exist -13,100 1.0 50% -4.1 89.5% -3.4 1,530 -5,257
RF, new 8,000 0.5 50% 1.3 89.5% 1.0 720 755
-6.0 -12,551
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install SF and RF VFD 0 2 LS $10,000 $20,000
Control modifications - CO2 sensor, pressure sensor, revise sequence 0 1 LS $15,000 $15,000
Commissioning 0 1 LS $5,000 $5,000
Estimating contingency 0 15%$6,000
Overhead & profit 0 15%$6,900
Design fees 0 10%$5,290
Project management 0 8%$4,655
Energy Costs
Electric Energy 1 - 25 -12,551 kWh $0.239 ($58,958)
Electric Demand 1 - 25 -54 kW $7.21 ($7,681)
Fuel Oil 1 - 25 -491 gal $4.12 ($57,429)
Net Present Worth ($61,200)
Craig High School 28 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-19: Optimize Heating System
Energy Analysis
Boiler Efficiency
Boilers Input MBH Loss %Loss MBH Hours, exist kBtu η boiler Gallons
-2 3,988 0.75% -60 3,600 -215,341 68% -2,286
2 2,292 0.75% 34 3,600 123,750 68% 1,314
-25 -91,591 -973
Pumping Efficiency
Primary Pumps
GPM ΔP η, pump BHP η, motor kW Hours kWh
-590 32 65% -9.8 91% -8.1 3,600 -28,999
229 15 65% 1.8 91% 1.5 3,600 5,280
Secondary Pumps
-68 24 60% -0.9 86% -0.8 3,600 -2,873
-44 14 55% -0.4 70% -0.4 3,600 -1,454
-350 26 65% -4.7 89% -4.0 3,600 -14,291
229 26 55% 3.7 89% 3.1 3,600 11,059
-8.7 -31,279
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Optimization Analysis 0 1 LS $14,000 $14,000
Reduce boiler size 0 80 hrs $150 $12,000
Repipe heating loops 0 1 LS $25,000 $25,000
Estimating contingency 0 15%$7,650
Overhead & profit 0 30% $17,595
Design fees 0 10%$7,625
Project management 0 8%$6,710
Annual Costs
Pump maintenance 1 - 25 -4 LS $200.00 ($15,427)
Energy Costs
Electric Energy 1 - 25 -31,279 kWh $0.062 ($38,257)
Electric Demand 1 - 25 -104 kW $10.83 ($22,202)
Fuel Oil 1 - 25 -973 gal $3.42 ($94,379)
Net Present Worth ($79,700)
Craig High School 29 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-20: Optimize Commons AHU-4
Energy Analysis
Ventilation Savings
Case SA CFM % OSA OSA CFM ΔT Hours kBtu η boiler Gallons
Existing -10,470 15% -1,571 30 1,530 -77,853 68%-827
New 6,000 10% 600 30 1,530 29,743 68%316
-971 -511
Fan Savings
Case CFM ΔP η, fan BHP η, motor kW Hours kWh
SF, exist -10,470 1.8 50% -5.9 91.7% -4.8 1,530 -7,381
SF, new 6,000 1.2 50% 2.3 91.7% 1.8 1,530 2,820
RF, exist -10,471 0.8 50% -2.6 89.5% -2.2 1,530 -3,361
RF, new 6,000 0.4 50% 0.8 89.5% 0.6 1,530 963
-4.5 -6,960
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install SF and RF VFD 0 2 LS $9,000 $18,000
Control modifications - CO2 sensor, pressure sensor, revise sequence 0 1 LS $15,000 $15,000
Commissioning 0 1 LS $5,000 $5,000
Estimating contingency 0 15%$5,700
Overhead & profit 0 15%$6,555
Design fees 0 10%$5,026
Project management 0 8%$4,422
Energy Costs
Electric Energy 1 - 25 -6,960 kWh $0.239 ($32,692)
Electric Demand 1 - 25 -41 kW $7.21 ($5,802)
Fuel Oil 1 - 25 -511 gal $4.12 ($59,703)
Net Present Worth ($38,500)
Craig High School 30 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-21: Install Boiler Room Heat Recovery
Energy Analysis
Heat Recovery
Boiler gph Jacket Loss MBH Hours Loss, kBtu Factor Recovery, kBtu η boiler Gallons
28 -1.0% -39 4,000 -155,120 50% -77,560 84%-667
Fan Energy
MBH ΔT CFM ΔP η, fan # Fans Hours kW kWh
39 25 1,436 1.50 35%2 5,000 1.4 7,221
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
700 CFM HRV 0 1 LS $7,500 $7,500
Ductwork 0 1 LS $4,000 $4,000
Electrical 0 1 LS $1,500 $1,500
Estimating contingency 0 15%$1,950
Overhead & profit 0 30%$4,485
Design fees 0 10%$1,944
Project management 0 8%$1,710
Annual Costs
HRV maintenance 1 - 25 4 hrs $60.00 $4,628
Energy Costs
Electric Energy 1 - 25 7,221 kWh $0.239 $33,921
Electric Demand 1 - 25 17.3 kW $7.21 $2,456
Fuel Oil 1 - 25 -667 gal $4.12 ($77,917)
Net Present Worth ($13,800)
Craig High School 31 Energy Audit (October 2011)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
EEM-22: Reduce Locker Room Lighting
Energy Analysis
Electric Savings
Fixture Number Hours, exist Hours, new watts, fixture kWh
2T8 36 2,000 1,000 74 -2,650
CFL 14 2,000 1,000 30 -419
-3,068
Added Heating Load
kWh Factor kBtu η boiler Gallons
3,068 45% 4,711 68% 50
Lamp Replacement
Type # Fixtures # Lamps Life, hrs Lamps//yr $/lamp Labor/lamp
2T8 36 -2 36,000 -2 $3 $5.00
CFL 14 -1 8,000 -2 $6 $2.00
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install occupancy sensors 0 4 LS $1,000 $4,000
Estimating contingency 0 15% $600.00
Overhead & profit 0 30% $1,380.00
Design fees 0 10%$598
Project management 0 8%$526
Annual Costs
Existing lamp replacement, 2T8 1 - 25 -2 lamps $8.00 ($309)
Existing lamp replacement, CFL 1 - 25 -2 lamps $8.00 ($270)
Energy Costs
Electric Energy 1 - 25 -3,068 kWh $0.239 ($14,413)
Fuel Oil 1 - 25 50 gal $4.12 $5,846
Net Present Worth ($2,000)
Craig High School 32 Energy Audit (October 2011)
Appendix B
Energy and Utility Data
Craig High School 33 Energy Audit (October 2011)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
ELECTRIC RATE
Alaska Power Company Bulk Power A-3
Craig
Hydaburg
Thorn Bay
Electricity ($ / kWh )$0.0786
Cost of Power Adjustment ($ / kWh)$0.1534
Demand ( $ / kW )$7.00
Customer Charge ( $ / mo )$140.86
Sales Tax ( % )0.0%
ELECTRICAL CONSUMPTION AND DEMAND
kWh kW kWh kW kWh kW kWh kW
Jan 22,800 90 26,800 90 25,040 94 24,080 97 24,680
Feb 28,400 90 28,800 90 31,600 94 30,240 84 29,760
Mar 22,800 90 25,200 90 26,000 97 23,440 86 24,360
Apr 25,600 90 26,480 82 25,040 93 24,240 88 25,340
May 24,400 80 21,680 85 26,080 88 23,600 82 23,940
Jun 16,000 70 19,040 80 19,520 79 9,600 70 16,040
Jul 13,200 40 5,920 34 14,720 38 8,400 53 10,560
Aug 8,400 30 6,320 30 14,640 50 8,400 53 9,440
Sep 19,200 70 16,720 74 11,920 85 14,800 76 15,660
Oct 23,600 90 23,520 88 23,600 21,760 85 23,120
Nov 27,600 80 28,080 94 28,640 97 31,280 86 28,900
Dec 26,800 90 28,480 96 29,680 97 27,360 92 28,080
Total 258,800 257,040 276,480 247,200 259,880
Average 21,567 76 21,420 78 23,040 83 20,600 79 21,657
Load Factor 39%38%38%36%79
ELECTRIC BILLING DETAILS
Month Energy Demand Cust & Tax Total Energy Demand Cust & Tax Total % Change
Jan $5,809 $659 $141 $6,609 $5,587 $678 $141 $6,405 -3.1%
Feb $7,331 $655 $141 $8,127 $7,016 $588 $141 $7,745 -4.7%
Mar $6,032 $682 $141 $6,854 $5,438 $605 $141 $6,184 -9.8%
Apr $5,809 $649 $141 $6,599 $5,624 $616 $141 $6,381 -3.3%
May $6,051 $617 $141 $6,809 $5,475 $571 $141 $6,187 -9.1%
Jun $4,529 $554 $141 $5,224 $2,227 $493 $141 $2,861 -45.2%
Jul $3,415 $268 $141 $3,824 $1,949 $370 $141 $2,459 -35.7%
Aug $3,396 $353 $141 $3,890 $1,949 $370 $141 $2,459 -36.8%
Sep $2,765 $595 $141 $3,501 $3,434 $532 $141 $4,106 17.3%
Oct $5,475 $0 $141 $5,616 $5,048 $594 $141 $5,783 3.0%
Nov $6,644 $678 $141 $7,463 $7,257 $605 $141 $8,003 7.2%
Dec $6,886 $678 $141 $7,704 $6,348 $644 $141 $7,132 -7.4%
Total $ 64,143 $ 6,387 $ 1,690 $ 72,221 $ 57,350 $ 6,664 $ 1,690 $ 65,705 -9.0%
Average $ 5,345 $ 532 $ 141 $ 6,018 $ 4,779 $ 555 $ 141 $ 5,475 -9.0%
Cost ($/kWh)$0.261 87% 10% 3% $0.266 1.8%
Month 2007 2008 2009 Average
Electrical costs are based on the current electric rates.
2009 2010
2010
Craig High School 34 Energy Audit (October 2011)
Alaska Energy Engineering LLC Annual Electric Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Use (kWh)Month of the Year
Electric Use History
2007
2008
2009
2010
0
20
40
60
80
100
120
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Demand (kW)Month of the Year
Electric Demand History
2007
2008
2009
2010
Craig High School 35 Energy Audit (October 2011)
Alaska Energy Engineering LLC Electric Cost
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School 2010
December 6, 2011
$ 0
$ 1,000
$ 2,000
$ 3,000
$ 4,000
$ 5,000
$ 6,000
$ 7,000
$ 8,000
$ 9,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Cost (USD)Month of the Year
Electric Cost Breakdown
2010
Electric Use (kWh) Costs
Electric Demand (kW) Costs
Customer Charge and Taxes
0
20
40
60
80
100
120
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Electric Demand (kW)Electric Use (kWh)Month of the Year
Electric Use and Demand Comparison
2010
Electric Use
Electric Demand
Craig High School 36 Energy Audit (October 2011)
Alaska Energy Engineering LLC Annual Fuel Oil Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
Year Fuel Oil Degree Days
2,007 19,489 7,430
2,008 16,321 7,385
2,009 19,727 7,538
2,010 15,072 7,390
5,000
5,500
6,000
6,500
7,000
7,500
8,000
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
22,000
2007 2008 2009 2010 Degree DaysGallons of Fuel OilYear
Annual Fuel Oil Use
Fuel Oil
Degree Days
Craig High School 37 Energy Audit (October 2011)
Alaska Energy Engineering LLC Annual Electric Consumption and Cost
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Craig High School
Energy Cost $/MMBTU Area ECI EUI
Fuel Oil $3.89 $40.12 44,492 $2.94 75
Electricity $0.266 $82.00
Source Cost
Electricity 259,880 kWh $69,100 890 27%
Fuel Oil 18,100 Gallons $61,900 2,460 73%
Totals -$131,000 3,350 100%
Annual Energy Consumption and Cost
Consumption Energy, MMBtu
Craig High School 38 Energy Audit (October 2011)
Appendix C
Equipment Data
Craig High School 39 Energy Audit (October 2011)
MotorHP / Volts / RPM / EfficB-1 Boiler Room BoilerWeil McClain 13883270 MBHB-2 Boiler Room BoilerWeil McClain 13883270 MBHP-1AMechanical 136Boiler Circulation PumpArmstrong 4x4x8 438010 HP/ 208 V/ 1750 RPM/ 90.2%pump running 14 psi in 24 psi outP1-BMechanical 136Boiler Circulation PumpArmstrong 4x4x8 438010 HP/ 208 V/ 1750 RPM/ 90.2%P-2Mechanical 136Domestic Hot Water CirculationArmstrong Astro 50-B100 W/ 115 V/ 3000 RPMP-3AMechanical 136Perimeter Heat Armstrong 2x2x6 43801 HP/ 208 V/ 1725 RPM/ 82.5%P-3BMechanical 136Perimeter Heat Armstrong 2x2x6 43801 HP/ 208 V/ 1725 RPM/ 82.5%P-4AMechanical 136Shop Heat Armstrong 1.5B 1050-0011/3 HP/ 115 V/ 1725 RPM/ 60% no efficiency ratingP-4BMechanical 136Shop Heat Armstrong 1.5B 1050-0011/3 HP/ 115 V/ 1725 RPM/ 60%P-5AMechanical 136AHU Heating Coil Armstrong 4x4x8 43805 HP/ 208 V/ 1725 RPM/ 89.5%P-5BMechanical 136AHU Heating Coil Armstrong 4x4x8 43805 HP/ 208 V/ 1725 RPM/ 89.5%P-6 Shop 141MAU-1 Heating CoilArmstrong No Data1/4 HP/ 115/ 1725 RPMP-7Mechanical 140BAHU-1 Heating CoilArmstrong 1.5B 1050-0021/3 HP/ 115 V/ 1725 RPM/ 60%P-8Mechanical 160-BAHU-2 Preheat CoilArmstrong No Data1/4 HP/ 115/ 1725 RPMCapacityNotesCraig High School - Major Equipment InventoryUnit IDLocation Function Make Model
Craig High School 40 Energy Audit (October 2011)
MotorHP / Volts / RPM / EfficCapacity NotesCraig High School - Major Equipment InventoryUnit IDLocation Function Make ModelP-9Mechanical 160-BAHU-2 Heating CoilArmstrong 1.33 1030-003 1/4 HP/ 115/ 1725 RPMP-10Mechanical 160-BAHU-3 Preheat CoilArmstrong No Data1/6 HP/ 115 V/ 1725 RPMP-11Mechanical 160-BAHU-3 Hot Deck CoilArmstrong No Data1/6 HP/ 115 V/ 1725 RPMP-12Mechanical 160-BAHU-4 Heating CoilArmstrong No Data1/6 HP/ 115 V/ 1725 RPMP-13Mechanical 160-BAHU-5 Heating CoilArmstrong No Data3/4 HP/ 208 V/ 1140 RPM/ 75.5%Mechanical 160-BDomestic Hot Water HeaterAO Smith COF 140-255 255,000 BTU/HR 1/7 HP/ 115 V140 gal/ direct fuel oil heaterElectric 137 Transformer Square D 150T85HIS150 KVA 150 degrees C temp risenon TPI ratedAHU-1 Room 203 Classroom AHU Scott Springfield HQ-280-AHU-23400-HSF-1 Room 203 Supply Fan23,420 CFM 30 HP/ 208 V/ 1760 RPM/ 90.7%RF-1 Room 203 Return Fan23,420 CFM 7.5 HP/ 208 V/ 1760 RPM/ 88/5%AHU-2 Room 106-C Commons AHU Scott Springfield H2-125-AHU-10502HSF-2 Room 106-C Supply Fan10,470 CFM 10 HP/ 208 V/ 1760 RPM/ 89.5%RF-2 Room 106-C Return Fan10,470 CFM 3 HP/ 208 V/ 1725 RPM/ 86.5%AHU-3 Room 106-C Auditorium AHU Scott Springfield AQ-150-AHU-13100-H
Craig High School 41 Energy Audit (October 2011)
MotorHP / Volts / RPM / EfficCapacity NotesCraig High School - Major Equipment InventoryUnit IDLocation Function Make ModelSF-3 Room 106-C Supply Fan 13,100 CRM 10 HP/ 208 V/ 1760 RPM/ 89.5%RF-3 Room 106-C Return Fan13,100 CRM 3 HP/ 208 V/ 1725 RPM/ 86.5%AHU-4 Room 106-CLocker Room AHUScott Springfield HQ-15-AHU-1200-H 1,250 CFM 3 HP/ 208 V/ 1750 RPM/ 86.5%AHU-5 Room 106-C Gymnasium AHU Scott Springfield HQ-230-AHU-19300-HSF-5 Room 106-C Supply Fan19,300 CFM 15 HP/ 208 V/ 1760 RPM/ 91%RF-5 Room 106-C Return Fan19,300 CFM 7.5 HP/ 208 V/ 1560 RPM/ 88/5%MAU-1 Shop Make-Up Air3,680 CFM 3 HP/ 208 V/1740 RPM/ 86.5%EF-1 Restroom Exhaust1,420 CFM not availableEF-2 Locker Exhaust Loren Cook 165 CPV1,515 CFM 1/2 HP/ 115 V/ 1725 RPM EF-3 Kitchen Exhaust Nutone RL6330WW190 CFM not availableEF-4 Art Room Exhaust1,680 CFM not availableEF-5 Restroom Exhaust100 CFM not availableEF-6 Science Room General Exhaust Loren Cook 245CPV4,190 CFM 3/4 HP/ 208 V/ 1725 RPM EF-7 Seience Room Fume Hood1,200 CFM not available
Craig High School 42 Energy Audit (October 2011)
MotorHP / Volts / RPM / EfficCapacity NotesCraig High School - Major Equipment InventoryUnit IDLocation Function Make ModelEF-8 Math Room General Exhaust1,500 CFM not availableEF-9Home EconomicsGeneral Exhaust Loren Cook 180 CPV1,970 CFM 1/3 HP/ 115 V/ 1725 RPM EF-10Home EconomicsCooktop Exhaust Nutone190 CFM not availableEF-11Home EconomicsCooktop Exhaust Nutone190 CFM not availableEF-12Home EconomicsCooktop Exhaust Nutone190 CFM not availableEF-13Home EconomicsCooktop Exhaust Nutone190 CFM not availableEF-14 Press Box Ventilation250 CFM not availableEF-15 Science Prep General Exhaust Loren Cook 100 CPV750 CFM 1/2 HP/ 115 V/ 1725 RPM CS-1 Welding Shop Exhaust Fan CAR-MON CMB-201,800 CFM 1.5 HP/ 208 VCS-2 Welding Shop Welding Hood CAR-MON FH-34800 CFM not availableCS-3 Welding ShopVehicle Exhaust SystemCAR-MON LO-X56W850 CFM 3/4 HP/ 208 V
Craig High School 43 Energy Audit (October 2011)
Appendix D
Abbreviations
AHU Air handling unit
BTU British thermal unit
BTUH BTU per hour
CBJ City and Borough of Juneau
CMU Concrete masonry unit
CO2 Carbon dioxide
CUH Cabinet unit heater
DDC Direct digital controls
DHW Domestic hot water
EAD Exhaust air damper
EEM Energy efficiency measure
EF Exhaust fan
Gyp Bd Gypsum board
HVAC Heating, Ventilating, Air-
conditioning
HW Hot water
HWRP Hot water recirculating pump
KVA Kilovolt-amps
kW Kilowatt
kWh Kilowatt-hour
LED Light emitting diode
MBH 1,000 Btu per hour
MMBH 1,000,000 Btu per hour
OAD Outside air damper
RAD Return air damper
RF Return fan
SIR Savings to investment ratio
SF Supply fan
UV Unit ventilator
VAV Variable air volume
VFD Variable frequency drive
Craig High School 44 Energy Audit (October 2011)