HomeMy WebLinkAboutSEA-AEE-Wrangell High School 2012-EE
Wrangell High School
Wrangell Public Schools
Funded by:
Final Report
December 2011
Prepared by:
Energy Audit
Table of Contents
Section 1: Executive Summary 2
Section 2: Introduction 6
Section 3: Energy Efficiency Measures 9
Section 4: Description of Systems 16
Section 5: Methodology 19
Appendix A: Energy and Life Cycle Cost Analysis 22
Appendix B: Utility and Energy Data 30
Appendix C: Equipment Data 35
Appendix D: Abbreviations 39
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
Wrangell High School 1 Energy Audit (December 2011)
Section 1
Executive Summary
An energy audit of the Wrangell 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.
The Wrangell High School is a 58,096 square foot building that contains commons, classrooms,
offices, a music room, a gym, a kitchen, a library, locker rooms, storage, and mechanical support
spaces. The following summarizes our assessment of the building:
Building Assessment
Envelope
Energy conscious decisions were incorporated in the selection of features of the exterior envelope.
These include: non-aluminum framed windows and window curtain walls, arctic entries, and a
judicious number of windows throughout the building. Interior features such as lower ceilings and a
sensible amount of lighting in interior spaces also support a reasonably energy efficient design. A
large portion of the exterior walls also use wood framing, which is significantly superior to metal
studs without a thermal break.
Some opportunities to increase the energy efficiency of the building envelope were identified.
The gym wall construction consists of a concrete block wall with 4” metal studs attached to the
exterior surface on 24” centers, 4” rigid batt insulation between the studs, and a vertical wood siding
on the exterior. The insulation value of the concrete block is R-1. Although the wall is insulated
between the metal studs, there is no thermal break between the metal studs and the concrete, or the
metal studs and the outside air. Due to the high thermal conductivity of the metal studs, this decreases
the overall insulation value of the wall to R-5. Optimum energy efficiency targets for a newly
constructed wall are R-26. The siding on the gym wall is in poor condition. Energy Efficiency
Measure 12, Section 3, recommends increasing the insulation when the siding is replaced.
The Inverted Roof Membrane Assembly (IRMA) on the gym and surrounding flat roof spaces. This
style of roof typically has a membrane set on the roof deck, covered with 5” thick rigid insulation,
and a fabric cloth layer, then topped with stone ballast or roofing paver. The 5” thick rigid insulation
provides an insulation value of R-20 (assuming expanded polystyrene foam); however, it has been
determined that the IRMA is a flawed system that is particularly ineffective and inefficient in
Southeast Alaska. This is because the IRMA allows water to flow between the layers of insulation to
the waterproof membrane below before it flows to the roof drains. This presents a two-fold problem.
First, the expanded foam eventually becomes waterlogged and loses some of its insulating properties.
Secondly, any outdoor temperature water moving through the foam against the warm roof surface
below will remove heat as it travels to the roof drain. In a climate such as Wrangell’s, imagine the
number of days per year that the roof and underside of the ceiling is being cooled to the temperature
of the rain water. That number is simply the number of rainy days per year. Consideration of the
replacement of these roof sections with a tapered roof system buildup to optimum insulation levels,
supported by a life cycle cost analysis, is outlined in Section 3, Energy Efficiency Measure 17.
The exterior doors are not thermally broken and weather stripping is in poor condition. Weather
stripping should be replaced and, when replaced, exterior doors should include thermal breaks.
Wrangell High School 2 Energy Audit (December 2011)
Heating & Ventilation Systems
The building is heated by two electric boilers as the primary heat source and two fuel oil boilers as
supplemental sources. The hydronic heating system serves heat to nine air handling unit systems, fan
coil units, domestic hot water heating systems, and perimeter hydronic systems. The electric boilers
supply heat at a much lower cost than the fuel oil boilers and they require less maintenance.
The building hydronic heating pumps are variable speed pumps that modulate their energy
consumption with heating load. The boiler systems and associated equipment appear to be well
maintained and are providing good service. A control upgrade project in 2007 converted the high
school pneumatic controls to a DDC system, improving performance and efficiency.
The building utilizes constant flow air handling systems to deliver conditioned air within the building
envelope. The rate at which air is delivered is based on the square footage of the spaces and is not
currently controlled to decrease the delivery rate when fewer occupants are in a space. The gym is a
good example. This space is available for use 74 hours per week under the current schedule. It is
often minimally occupied. Energy will be saved if the ventilation exchange rate is reduced during
periods of low occupancy.
There is a significant amount of damaged duct insulation throughout the building. Energy will be
saved if the duct insulation is repaired.
The remainder of the heating and ventilating systems appear to be in good condition; however fairly
simple improvements can be made to improve its effectiveness and efficiency. These are outlined in
Section 3, Energy Efficiency Measures.
Lighting
Interior lighting consists primarily of T12 fluorescent fixtures throughout the school and metal halide
pendant fixtures in the gymnasium. Exterior lighting consists primarily of high pressure sodium
lighting. The additional heat produced by the T12 fluorescent fixtures is beneficial toward heating
the building. Since the building is primarily heated with electricity, there is no incentive to upgrade
the interior lighting. The current maintenance plan of replacing the T12 fixtures with more efficient
T8 fixtures only as the ballasts fail is a responsible approach to phasing in the newer and more
efficient T8 fixtures.
Summary
It is the assessment of the energy audit team that the building is energy efficient for its period of
construction. The main missing feature that is a stable of today’s high performance buildings is
variable flow ventilation systems that reduce air flow when cooling loads are low. Other areas of poor
performance are lack of sufficient roof insulation as a result of the IRMA systems and the exterior
walls of the gym.
Wrangell High School 3 Energy Audit (December 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: Replace Broken Window
EEM-3: Insulate Walls and Ceiling
EEM-5: Optimize SF-8 (Commons) HVAC System
EEM-6: Seal Fan System Access Doors
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-6: Isolate Standby Boiler $500 $4,100 ($91,400) ($86,800) 174.6
EEM-7: Optimize SF-3 (Gym) HVAC System $41,700 $0 ($178,000) ($136,300) 4.3
Medium Priority
EEM-8: Replace Aerators $1,500 $0 ($4,400) ($2,900) 2.9
EEM-9: Optimize SF-2 HVAC System $10,700 $0 ($18,400) ($7,700) 1.7
EEM-10: Upgrade Motors to Premium Efficiency $16,900 $0 ($25,900) ($9,000) 1.5
EEM-11: Optimize SF-9 (Music) HVAC System $8,200 $0 ($11,900) ($3,700) 1.5
EEM-12: Increase Gym Wall Insulation $103,100 $0 ($143,200) ($40,100) 1.4
EEM-13: Optimize 1st Fl. Classrooms HVAC System $13,300 $0 ($17,000) ($3,700) 1.3
Totals* $195,900 $4,100 ($490,200) ($290,200) 2.5
*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.
Wrangell High School 4 Energy Audit (December 2011)
Summary
The energy audit revealed numerous opportunities for improving the energy performance of the
building. 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.
Wrangell High School 5 Energy Audit (December 2011)
Section 2
Introduction
This report presents the findings of an energy audit of the Wrangell High School located in Wrangell,
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
The Wrangell High School is a 58,096 square foot building that contains commons, classrooms,
offices, a music room, a gym, a kitchen, a library, locker rooms, storage, and mechanical support
spaces.
The high school is operated by 21 staff and attended by 110 students. The facility is scheduled in the
following manner:
Classes, Offices, Library 7:30 am – 4:00 pm (M-F)
Commons, Gym 8:00 am – 10:00 pm (M-F)
10:00 am – 2:00 pm (Saturday)
Building History
1984 – Original Construction Phase I
1985 – Original Construction Phase II
2007 – Renovation Phase I
2008 – Renovation Phase II
2011 – Electric Boiler Installation
Wrangell High School 6 Energy Audit (December 2011)
Energy Consumption
The building energy sources include an electric service and a fuel oil tank. Electricity is the primary
source for the majority of the heating loads and domestic hot water while two fuel oil boilers serve as
a back-up heat source. The following table and charts show annual energy use and cost before the
electric boilers were installed in 2011. Insufficient data since the installation exists for this analysis.
Annual Energy Consumption and Cost
Source Consumption Cost Energy, MMBtu
Electricity 374,419 kWh $42,600 1,300 28%
Fuel Oil 24,008 Gallons $88,800 3,300 72%
Totals $131,400 4,600 100%
Electricity
This chart shows
electrical energy use from
2007 to 2010. The electric
boilers were installed in
2011 and data is not
available for the increased
electrical demand of the
high school.
The effective cost—
energy costs plus demand
charges—is 11.4¢ per
kWh.
Fuel Oil
This chart shows heating
energy use from 2007 to
2010. The chart compares
annual use with the
heating degree days (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.
Wrangell High School 7 Energy Audit (December 2011)
Cost of Heat Comparison
This chart shows a comparison of
the current cost of fuel oil heat and
electric heat. The comparison is
based on a fuel oil conversion
efficiency of 70% and an electric
boiler conversion efficiency of
95%.
Electric heat is currently less
expensive than fuel oil heat.
Wrangell High School 8 Energy Audit (December 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 A 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 high school exterior steel doors do not seal and are missing weather stripping.
Energy will be saved if doors are properly weather-stripped to reduce infiltration.
Scope: Replace weather stripping on exterior doors.
EEM-2: Replace Broken Window
Purpose: A 2’ x 5’ window in the commons area is broken and covered only with a single plexi-
glass sheet. Energy will be saved if the single pane is replaced with a double pane glazing
unit.
Scope: Repair broken window.
Wrangell High School 9 Energy Audit (December 2011)
EEM-3: Insulate Walls and Ceiling
Purpose: A 40 square foot section of ceiling space and 60 square foot section of wall space are
currently uninsulated in the northeast maintenance storage space of the school. Energy
will be saved if the walls are insulated to optimum levels of fill.
Scope: Install wall insulation in uninsulated wall stud cavities.
EEM-4: Optimize SF-4 (Gym Locker) HVAC System
Purpose: SF-4 is a constant volume ventilation system supplying conditioned air to the gym locker
rooms, wrestling room, storage rooms, and adjacent rooms.
Energy will be saved if the exhaust air damper control is changed from modulating in
sequence with the outside air damper to modulating the damper to maintain neutral
building pressure.
EEM-5: Seal Fan System Access Doors
Purpose: Many of the fan systems have access doors that do not seal tightly and are leaking.
Sealing the access doors will reduce air leakage.
Scope: Fix the latches and seals on access doors so they close tightly.
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-6: Isolate Standby Boiler
Purpose: Only one fuel oil boiler needs to be kept online as a backup to the electric boilers.
Circulating hot water through the other fuel oil boiler causes heat loss of 0.5% of the
input rating of the boiler due to it acting as a heat sink. Energy will be saved if the
standby fuel oil boiler is isolated from the system.
Scope: Shut down and isolate the standby fuel oil boiler. Switch the lag and standby boilers
semi-annually.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$240 ($5,820) ($5,580) $500 $4,100 ($91,400) ($86,800) 174.6
Wrangell High School 10 Energy Audit (December 2011)
EEM-7: Optimize SF-3 (Gym) HVAC System
Purpose: SF-3 is a constant volume ventilation system supplying conditioned air to the
gymnasium.
Energy will be saved if the system is converted to variable flow that turns down when the
gym is lightly occupied. Also, the controls can be optimized by sequentially controlling
the mixing dampers and heating coil to maintain room setpoint, with a CO2 sensor
override of the mixing dampers.
Scope: Perform the following modifications to the SF-3 system:
- Install VFDs on SF-3 and RF-11 and modify the controls to modulate fan speed with
cooling requirements in the gym.
- Modify the supply air temperature control to sequentially modulate the mixing
dampers and automatic valve to maintain room setpoint. Provide CO2 sensor override
of the mixing dampers to control CO2 levels.
- Modify the controls to modulate the exhaust air damper with gym pressure
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($11,350) ($11,350) $41,700 $0 ($178,000) ($136,300) 4.3
MEDIUM PRIORITY
Medium priority EEMs will 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, represent savings.
EEM-8: Replace Aerators
Purpose: Energy and water will be saved by replacing the lavatory aerators and showerheads with
low-flow models.
Scope: Replace lavatory aerators and showerheads with water-conserving fixtures.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($280) ($280) $1,500 $0 ($4,400) ($2,900) 2.9
Wrangell High School 11 Energy Audit (December 2011)
EEM-9: Optimize SF-2 (2nd Floor Classrooms) HVAC System
Purpose: SF-2 is a constant volume ventilation system supplying conditioned air to the second
floor classrooms. The system supplies a minimum of 2,660 cfm of outside air, an amount
that is sufficient for ventilating the entire school.
The system also provides make-up air for exhaust fans EF-1 (Toilets), EF-5 (Science),
EF-6 (Fume Hood) and EF-7 (Fume Hood). Of these only EF-1 is operating
continuously. Energy will be saved if the minimum outside air percentage is reduced to
10% and RF-4 is rebalanced to return more air to SF-2.
Scope: Perform the following modifications to the SF-1 system:
- Modify the SF-2 control sequence to decrease the minimum outside air percentage to
10%
- Rebalance RF-4 to return more air to SF-1
- Modify the controls to modulate the exhaust air damper with building pressure
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,170) ($1,170) $10,700 $0 ($18,400) ($7,700) 1.7
EEM-10: Upgrade Motors to Premium Efficiency
Purpose: The equipment inspection identified thirteen motors that could be upgraded with
premium efficiency models to save energy. They are:
- P-1 10 HP from 82.0% to 91.7% efficiency
- P-2 10 HP from 82.0% to 91.7% efficiency
- AC-1 2 HP from 71.0% to 86.5% efficiency
- SF-1 10 HP from 85.5% to 91.7% efficiency
- SF-3 7.5 HP from 88.5% to 91.0% efficiency
- SF-4 5 HP from 86.5% to 89.5% efficiency
- SF-8 3 HP from 85.5% to 89.5% efficiency
- RF-1 5 HP from 87.0% to 89.5% efficiency
- RF-4 3 HP from 86.0% to 89.5% efficiency
- RF-9 1 HP from 84.0% to 85.5% efficiency
- RF-10 1.5 HP from 84.0% to 86.5% efficiency
- RF-11 5 HP from 86.5% to 89.5% efficiency
- RF-12 2 HP from 84.0% to 86.5% efficiency
Scope: Replace identified motors with premium efficiency motors.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,650) ($1,650) $16,900 $0 ($25,900) ($9,000) 1.5
Wrangell High School 12 Energy Audit (December 2011)
EEM-11: Optimize SF-9 (Music) HVAC System
Purpose: SF-9 is a constant volume ventilation system supplying conditioned air to the music
room. The system is currently supplying 60° F air to the room.
Energy will be saved if the system is optimized by sequentially controlling the mixing
dampers and heating coil to maintain room setpoint, with a C02 sensor override of the
mixing dampers.
Scope: Perform the following modifications to the SF-9 system:
- Modify the supply air temperature control to sequentially modulate the mixing
dampers and automatic valve to maintain room setpoint. Provide a CO2 sensor
override of the mixing dampers to control CO2 levels.
- Modify the controls to modulate the exhaust air damper with room pressure
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($760) ($760) $8,200 $0 ($11,900) ($3,700) 1.5
EEM-12: Increase Gym Wall Insulation
Purpose: The gym wall assembly consists of concrete and metal stud construction without a
thermal break. The walls have an estimated R-5 insulation value. An optimal R-value by
current construction standards is R-26. Energy will be saved if the insulation level of the
walls is increased. The construction of the walls allows for adding exterior foam
insulation and new siding.
Scope: The siding on the gym wall is rotting and at the end of its service life. When the siding is
replaced, a minimum of 4” of exterior foam insulation should be installed. This analysis
includes the cost of installing insulation at the time of a re-siding project.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($9,130) ($9,130) $103,100 $0 ($143,200) ($40,100) 1.4
EEM-13: Optimize SF-1 (1st Floor Classrooms) HVAC System
Purpose: SF-1 is a constant volume ventilation system supplying conditioned air to the first floor
classrooms. The system supplies a minimum of 2,950 cfm of outside air, which is
sufficient for ventilating the entire school.
Energy will be saved if the SF-1 controls are modified to decrease the minimum outside
air percentage to 10%.
Scope: Perform the following modifications to the SF-1 system:
- Modify the SF-1 control sequence SF-1 to decrease the minimum outside air
percentage to 10%
- Rebalance RF-1 to return more air to SF-1
- Modify the controls to modulate the exhaust air damper with building pressure
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,090) ($1,090) $13,300 $0 ($17,000) ($3,700) 1.3
Wrangell High School 13 Energy Audit (December 2011)
LOW PRIORITY
Low priority EEMs do not offer a life cycle energy savings and are not recommended.
EEM-14: Upgrade Exterior Lighting to LED
Purpose: The existing perimeter parking lot lighting consists of metal halide and high pressure
sodium fixtures. These fixture styles are less efficient than LED lighting and the lamp life
is much shorter.
Scope: Replace these existing exterior lights with LED lights.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$250 ($2,420) ($2,170) $36,900 ($200) ($38,000) ($1,300) 1.0
EEM-15: Optimize SF-8 (Commons) HVAC System
Purpose: SF-8 is a constant volume ventilation system supplying conditioned air to the commons.
The system also provides make-up air for EF-4 (kitchen hood). EF-4 is operating
continuously 5:00 am to 1:00 pm. Most of the time, the fan could operate at reduced
capacity and still remove cooking odors and moisture.
Energy will be saved if the EF-4 motor is replaced with a 2-speed motor so it can operate
at low speed except when cooking activities warrant full speed exhaust. In addition,
change the exhaust air damper control from modulating in sequence with the outside air
damper to modulating the damper to maintain neutral building pressure.
Scope Replace the EF-4 motor with a 2-speed motor and controller and change the exhaust air
damper control so it modulates to maintain the building at neutral pressure.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($2,010) ($2,010) $41,700 $0 ($31,500) $10,200 0.8
EEM-16: Replace Gym Lights
Purpose: Existing gym lighting utilizes 30 pendant-mounted metal halide lamps to support school-
hour class activities and after-school sports and community events. Similar light levels
could be achieved with multi-lamp T5 lighting. Energy will be saved if the 30 metal
halide light fixtures were replaced with 6-bulb T5 units; however, the heat produced with
the existing fixtures is beneficial toward heating the building.
Scope: Replace metal halide lights with 6-bulb T5 units.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($100) ($890) ($990) $28,000 ($1,600) ($14,000) $12,400 0.6
Wrangell High School 14 Energy Audit (December 2011)
EEM-17: Replace Gym Roof
Purpose: The high school gym utilizes a base layer of foam that was approximately 5” thick on the
underside of the pavers. The 5” thickness would normally produce an insulation value of
R-20 with the use of the expanded polystyrene foam; however, the IRMA roof system is
de-rated by approximately 50% as outlined in the executive summary. This results in an
overall roof insulation value of only R-10 for 11,796 square feet of roofing. The gym
roofing should be replaced with a tapered roof system similar to that used in the school
re-roofing project, but with an optimum insulation value of R-46.
Scope: Replace the gym IRMA roof system with R-46 tapered roof system. The energy savings
will not offset the cost of replacing the entire roof assembly. When the roof requires
replacement, the new assembly should include R-46 insulation under the roof membrane.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($8,090) ($8,090) $314,300 $0 ($126,900) $187,400 0.4
Wrangell High School 15 Energy Audit (December 2011)
Section 4
Description of Systems
ENERGY SYSTEMS
This section provides a general description of the building systems. Energy conservation
opportunities are addressed in the Energy Efficiency Measure section of the report.
Building Envelope
R-value
Component Description (inside to outside) Existing Optimal
Exterior Walls 5/8” Gyp. bd, 2”x6” stud, R-19 batt, ½” plywood, siding R-20 R-26
Gym Walls 8” concrete block, 4” metal studs w/4” semi rigid batt, siding R-5 R-26
Gable Roof 24” o.c. trusses w/ R-38 batt, 5/8” gyp. bd. R-38 R-46
Flat Roof ¾” plywood sheathing, IRMA buildup (5” rigid foam, paver) R10 R-46
Floor Slab 4” Concrete slab-on-grade R-10 R-10
Foundation 8” concrete w/ 2” perimeter insulation board R-10 R-20
Windows Vinyl double pane windows R-1.5 R-5
Doors Steel & Aluminum doors w/ non-thermally broken frames R-1.5 R-5
Heating System
The building is heated by two electric boilers as the primary heat source and two fuel oil boilers as
backup heat sources that provide heat to nine air handling unit systems, fan coil units, and perimeter
hydronic systems. The heating system has the following pumps:
P-1 & P-2 are boiler circulation pumps
EBHRP-1 is the heating loop return pump for electric boiler EB-1
EBHRP-2 is the heating loop return pump for electric boiler EB-2
P-6 is a domestic hot water heating pump
HWRP-1 is the domestic hot water recirculating pump
HWRP-2 is the domestic hot water recirculating pump for the gymnasium
Wrangell High School 16 Energy Audit (December 2011)
Ventilation Systems
Area Fan System Description
1st Floor SF-1 13,800 cfm 10 HP constant volume air handling unit consisting of a mixing
box, filter section, primary heating coil, supply fan, and return fan (RF-1)
2nd Floor SF-2 13,300 cfm 10 HP constant volume air handling unit consisting of a mixing
box, filter section, primary heating coil, supply fan, and return fan (RF-4)
Gymnasium SF-3 16,500 cfm 7.5 HP constant volume air handling unit consisting of a
mixing box, filter section, primary heating coil, supply fan, and return fan
(RF-3)
Gym Lockers SF-4 7,000 cfm 5 HP constant volume air handling unit consisting of a mixing
box, filter section, primary heating coil, supply fan, and return fan (RF-12)
Commons SF-8 5,500 cfm 3 HP constant volume air handling unit consisting of a mixing
box, filter section, primary heating coil, supply fan, and return fan (RF-10)
Music SF-9 2,600 cfm 1.5 HP constant volume air handling unit consisting of a mixing
box, filter section, primary heating coil, supply fan, and return fan (RF-9)
First Floor RF-1 10,850 cfm 5 HP constant volume fan
Art Room 129 Exhaust RF-2 1,050 cfm ½ HP constant volume fan
Dust Room 130 Exhaust RF-3 960 cfm ½ HP constant volume fan
2nd Floor RF-4 8,100 cfm 3 HP constant volume fan
Science Room 220 Exhaust RF-5 1,460 cfm ½ HP constant volume fan
Science Room 222 Exhaust RF-6 1,250 cfm ½ HP constant volume fan
Dark Room Exhaust RF-7 240 cfm 1/6 HP constant volume fan
Music RF-9 2,600 cfm 1 HP constant volume fan
Commons RF-10 4,400 cfm 1.5 HP constant volume fan
Gymnasium RF-11 13,600 cfm 5 HP constant volume fan
Gym Lockers RF-12 6,000 cfm 2 HP constant volume fan
Toilet Exhaust EF-1 930 cfm ¼ HP constant volume exhaust air fan
Art Room 129 Exhaust EF-2 250 cfm 1/40 constant volume exhaust air fan
Paint Spray Booth Art Rm 129 EF-3 1,170 cfm ½ hp constant volume exhaust air fan
Kitchen Hood Room 103 EF-4 1,625 cfm ½ hp constant volume exhaust air fan
Store Room 221 Exhaust EF-5 750 cfm 1/3 HP constant volume exhaust air fan
Fume Hood Room 221 EF-6 670 cfm ½ HP constant volume exhaust air fan
Fume Hood Room 220 EF-7 1,100 cfm ½ HP constant volume exhaust air fan
Mechanical Room 111 EF-8 1,000 cfm ¼ HP constant volume exhaust air fan
Animal Cage Exhaust Rm 222 EF-9 100 cfm 1/50 HP constant volume exhaust air fan
Commons EF-10 600 cfm 1/3 HP constant volume exhaust air fan
Gymnasium EF-11 1,500 cfm ½ HP constant volume exhaust air fan
Gym Lockers EF-12 1,060 cfm ½ HP constant volume exhaust air fan
Wrangell High School 17 Energy Audit (December 2011)
Domestic Hot Water System
The domestic hot water heating system serving the high school consists of one 50-gallon State Select
4500-watt direct hot water heater that is not currently used, and one Amtrol 80-gallon indirect hot
water heater. The gym and pool locker rooms are served by four JASS 120-gallon indirect hot water
heaters.
Automatic Control System
The building has a DDC system to control the operation of the heating and ventilation systems.
Energy can be saved through further optimization of fan system scheduling combined with a retro-
commissioning of the air handler systems.
Lighting
Interior lighting consists primarily of T12 fluorescent fixtures throughout the school and metal halide
pendant fixtures in the gymnasium. Exterior lighting consists primarily of high pressure sodium
lighting. Because the additional heat produced by the T12 fluorescent fixtures is beneficial toward
heating the building, the current maintenance plan of replacing the T12 fixtures with more efficient
T8 fixtures only as the ballasts fail is a responsible approach to phasing in the newer and more
efficient T8 fixtures.
Electric Equipment
Equipment for commercial food preparation is located in the kitchen.
Wrangell High School 18 Energy Audit (December 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.
Wrangell High School 19 Energy Audit (December 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 $3.70 per gallon for a seasonally adjusted blend of #1 and #2 fuel oil. The
analysis is based on 6% fuel oil inflation which has been the average for the past 20-years.
Electricity
Electricity is supplied by Wrangell Municipal Light & Power. The building is billed for electricity
under their Large Commercial rate. Electric rates have been stable in Wrangell with inflation less than
1%. This trend will continue as long as surplus power from Tyee Lake is available.
Large Power Interruptible
Electricity ($ / kWh ) Block Rate
1st Block 70,000 $0.107
2nd Block $0.103
Customer Charge $13.50
Wrangell High School 20 Energy Audit (December 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 $0.114/kWh
General Inflation Rate 2% Electricity Inflation 1%
Fuel Oil Cost (2012) $3.70/gal Fuel Oil Inflation 6%
Wrangell High School 21 Energy Audit (December 2011)
Appendix A
Energy and Life Cycle Cost Analysis
Wrangell High School 22 Energy Audit (December 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
Building Name
Basis
Economic
Study Period (years) 25 Nominal Discount Rate 5%General Inflation 2%
Energy
2011 $/gal Fuel Inflation 2012 $/gal
Fuel Oil $3.70 6% $3.92
Electricity $/kWh (2011)$/kW (2011)Inflation $/kWh (2012)$/kW (2012)
w/ Demand Charges $0.107 $0.00 1% $0.108 $0.00
w/o Demand Charges $0.107 -1% $0.108 -
EEM-6: Isolate Standby Boiler
Energy Analysis
Boiler Input MBH Loss %Loss MBH Hours, exist Hours, new kBtu η boiler kWh
B-1 3,988 0.50% 20 8,760 0 -174,679 95% -53,890
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Shutdown and isolate fuel oil boiler 0 1 ea $500 $500
Annual Costs
Switchover standby boiler 1 - 25 4 ea $60.00 $4,086
Energy Costs
Electric Energy 1 - 25 -53,890 kWh $0.108 ($91,363)
Net Present Worth ($86,800)
EEM-7: Optimize SF-3 (Gym) HVAC System
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
SF-3 Existing -16,500 1.625 55%-8 91%-6 2,700 -16,977
Optimized 10,000 1.25 55%4 91%3 2,700 7,915
RF-11 Existing -13,600 1.00 55%-4 90%-3 2,700 -8,755
Optimized 9,500 0.75 55%2 90%2 2,700 4,587
-5 -13,231
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-3 Existing -16,500 60 68 -143 2,700 -384,912 95% -118,749
Optimized 10,000 65 68 32 2,700 87,480 95%26,988
-297,432 -91,760
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Modify CO2, SAT, and EAD controls 0 1 ea $7,500 $7,500
Install VFD 0 2 LS $7,500 $15,000
Commissioning 0 1 LS $1,000 $1,000
Estimating contingency 0 15%$3,525
Overhead & profit 0 30%$8,108
Design fees 0 10%$3,513
Project management 0 8%$3,092
Energy Costs
Electric Energy 1 - 25 -104,991 kWh $0.108 ($177,998)
Net Present Worth ($136,300)
Wrangell High School 23 Energy Audit (December 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
Building Name
EEM-8: Replace Aerators
Energy Analysis
Fixture Existing Proposed Uses/day Days Water,Gals % HW kBTU kWh
Showerhead 20.0 10.0 10 60 -6,000 80% -3,203 -939
Lavatories 0.3 0.2 330 180 -10,692 80% -5,707 -1,673
-16,692 -2,611
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace lavatory aerators 0 20 ea $35 $700
Replace showerhead 0 24 ea $35 $840
Energy Costs
Electric Energy (Effective Cost)1 - 25 -2,611 kWh $0.108 ($4,427)
Net Present Worth ($2,900)
EEM-9: Optimize SF-2 HVAC System
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
RF-4 Existing -8,100 1.00 55%-2 88%-2 1,620 -3,200
Optimized 9,000 1.10 55%3 88%2 1,620 3,911
711
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-2 Existing -13,300 63.5 70 -93 1,620 -151,253 95% -46,663
Optimized 13,000 65 70 70 1,620 113,724 95%35,085
-37,529 -11,578
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Modify SF-2 controls 0 1 LS $4,000 $4,000
Rebalance RF-4 0 1 LS $1,000 $1,000
Commissioning 0 1 LS $1,000 $1,000
Estimating contingency 0 15%$900
Overhead & profit 0 30%$2,070
Design fees 0 10%$897
Project management 0 8%$789
Energy Costs
Electric Energy 1 - 25 -10,867 kWh $0.108 ($18,423)
Net Present Worth ($7,800)
Gallons per Use
Wrangell High School 24 Energy Audit (December 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
Building Name
EEM-10: Upgrade Motors to Premium Efficiency
Energy Analysis
Equip Number HP ηold ηnew kW Hours kWh
RF-9 1 1 84.0% 85.5% -0.01 1,620 -18
RF-10 1 1.5 84.0% 86.5% -0.03 1,620 -45
RF-12 1 2 84.0% 86.5% -0.04 2,920 -109
AC-1 1 2 71.0% 86.5% -0.23 2,920 -675
SF-8 1 3 85.5% 89.5% -0.09 1,620 -145
RF-4 1 3 86.0% 89.5% -0.08 1,620 -127
RF-11 1 5 86.5% 89.5% -0.11 1,620 -181
SF-4 1 5 86.5% 89.5% -0.11 1,620 -181
RF-1 1 5 87.0% 89.5% -0.09 1,620 -151
SF-3 1 7.5 88.5% 91.0% -0.14 1,620 -227
SF-1 1 10 85.5% 91.7% -0.46 1,620 -749
P-1/P-2 2 10 82.0% 91.7% -1.45 8,760 -12,678
-2.8 -15,287
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs HP
Replace motor 1 0 1 LS 940 $940
Replace motor 1.5 0 1 LS 955 $955
Replace motor 2 0 2 LS 970 $1,940
Replace motor 3 0 2 LS 1,080 $2,160
Replace motor 5 0 3 LS 1,290 $3,870
Replace motor 7.5 0 1 LS 1,690 $1,690
Replace motor 10 0 3 LS 1,790 $5,370
Energy Costs
Electric Energy 1 - 25 -15,287 kWh $0.108 ($25,917)
Net Present Worth ($9,000)
EEM-11: Optimize SF-9 (Music) HVAC System
Energy Analysis
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-9 Existing -2,600 60 70 -28 1,620 -45,490 95% -14,034
Optimized 2,600 65 70 14 1,620 22,745 95%7,017
-22,745 -7,017
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Modify SF-2 controls, Add CO2 control 0 1 LS $4,000 $4,000
Commissioning 0 1 LS $600 $600
Estimating contingency 0 15%$690
Overhead & profit 0 30%$1,587
Design fees 0 10%$688
Project management 0 8%$605
Energy Costs
Electric Energy 1 - 25 -7,017 kWh $0.108 ($11,896)
Net Present Worth ($3,700)
Wrangell High School 25 Energy Audit (December 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
Building Name
EEM-12: Increase Gym Wall Insulation
Energy Analysis
Component Area R,exist R,new ΔT MBH kBtu η boiler kWh
Wall 6,448 5 26 30 -31.2 -273,732 95% -84,449
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install wall insulation 0 6,448 sqft $9 $58,032
Estimating contingency 0 15%$8,705
Overhead & profit 0 30% $20,021
Design fees 0 10%$8,676
Project management 0 8%$7,635
Energy Costs
Electric Energy 1 - 25 -84,449 kWh $0.108 ($143,172)
Net Present Worth ($40,100)
EEM-13: Optimize SF-1 (1st Floor Classrooms) HVAC System
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
RF-1 Existing -10,850 1.00 55%-3 90%-3 1,620 -4,191
Optimized 12,975 1.25 55%5 90%4 1,620 6,265
EF-4 Existing -1,625 0.63 50% -0.3 80%0 1,620 -483
Optimized 825 0.63 50%0 80%0 1,620 245
1,836
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-1 Existing -13,800 63.4 70 -98 1,620 -159,261 95% -49,134
Optimized 13,800 65 70 75 1,620 120,722 95%37,244
-38,539 -11,890
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Modify SF-1 controls 0 1 LS $4,000 $4,000
Install 2-spoeed motor on EF-4 0 1 LS $2,500 $2,500
Commissioning 0 1 LS $1,000 $1,000
Estimating contingency 0 15%$1,125
Overhead & profit 0 30%$2,588
Design fees 0 10%$1,121
Project management 0 8%$987
Energy Costs
Electric Energy 1 - 25 -10,054 kWh $0.108 ($17,044)
Net Present Worth ($3,700)
Wrangell High School 26 Energy Audit (December 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
Building Name
EEM-14: Upgrade Exterior Lighting to LED
Energy Analysis
Type # Fixtures Lamp Lamp, watts Fixture Watts Lamp Lamp, watts Fixture Watts Savings, kWh
WallPak 46 HPS 70 95 LED -40 -11,081
WallPak 2 HPS 100 128 LED -60 -596
Cobra Head 13 HPS 250 295 LED -106 -10,762
-22,439
Lamp Replacement
Type # Fixtures Lamp # Lamps Life, hrs Lamps//yr $ / lamp $ / Replace
WallPak 46 HPS -1 24,000 -8.40 $42 $15
WallPak 2 HPS -1 24,000 -0.37 $32 $15
Cobra Head 13 HPS -1 24,000 -2.37 $50 $60
WallPak 46 LED 1 60,000 3.36 $125 $15
WallPak 2 LED 1 60,000 0.15 $190 $15
Cobra Head 13 LED 1 60,000 0.95 $200 $60
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace WallPak: 70 watt HPS with LED 0 46 LS $525 $24,150
Replace WallPak: 100 watt HPS with LED 0 2 LS $525 $1,050
Replace Cobra Head: 250 watt HPS with LED 0 13 LS $900 $11,700
Annual Costs
Existing lamp replacement, 70 watt HPS 1 - 25 -8.40 lamps $57.00 ($8,148)
Existing lamp replacement, 100 watt HPS 1 - 25 -0.37 lamps $47.00 ($292)
Existing lamp replacement, 250 watt HPS 1 - 25 -2.37 lamps $110.00 ($4,444)
LED board replacement, 40 watts 1 - 25 3.36 LED board $140.00 $8,005
LED board replacement, 60 watts 1 - 25 0.15 LED board $205.00 $510
LED board replacement, 106 watts 1 - 25 0.95 LED board $260.00 $4,201
Energy Costs
Electric Energy 1 - 25 -22,439 kWh $0.108 ($38,042)
Net Present Worth ($1,300)
Existing Replacement
Wrangell High School 27 Energy Audit (December 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
Building Name
EEM-15: Optimize SF-8 (Commons) System
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
SF-8 Existing -5,500 1.50 55%-2 88%-2 1,620 -3,260
Optimized 3,500 1.25 55%1 88%1 1,620 1,729
RF-10 Existing -4,400 1.00 55%-1 90%-1 1,620 -1,700
Optimized 9,500 0.75 55%2 90%2 1,620 2,752
0 -478
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-8 Existing -5,500 60 68 -48 1,620 -76,982 95% -23,750
Optimized 3,500 65 68 11 1,620 18,371 95%5,668
-58,612 -18,082
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Modify CO2, SAT, and EAD controls 0 1 ea $7,500 $7,500
Install VFD 0 2 LS $7,500 $15,000
Commissioning 0 1 LS $1,000 $1,000
Estimating contingency 0 15%$3,525
Overhead & profit 0 30%$8,108
Design fees 0 10%$3,513
Project management 0 8%$3,092
Energy Costs
Electric Energy 1 - 25 -18,561 kWh $0.108 ($31,467)
Net Present Worth $10,300
EEM-16: Replace Gym Lights
Energy Analysis
Lamp Lamp, watts Fixture Watts Lamp Lamp, watts Fixture Watts kW Hours kWh
MH 400 460 T5 310 357 -3.1 2,664 -8,272
Lamp Replacement
# Fixtures Lamp # Lamps Life, hrs Replace/yr $/lamp replace
30 MH -1 20,000 -4.00 $30
30 T5 6 30,000 2.66 $24
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace 400 watt MH with T5 Fluorescent 0 30 LS $525 $15,750
Estimating contingency 0 15%$2,363
Overhead & profit 0 30%$5,434
Design fees 0 10%$2,355
Project management 0 8%$2,072
Annual Costs
Existing lamp replacement, 400 watt MH 1 - 25 -4.00 replacements $60.00 ($4,082)
New lamp replacement, T5 1 - 25 2.66 replacements $54.00 $2,449
Energy Costs
Electric Energy 1 - 25 -8,272 kWh $0.108 ($14,024)
Net Present Worth $12,300
Fixtures
30
Existing Replacement Savings
Wrangell High School 28 Energy Audit (December 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
Building Name
EEM-17: Replace Gym Roof
Energy Analysis
Component Area R,exist R,new ΔT MBH kBtu η boiler kWh
Roof 11,796 10 46 30 -27.7 -242,608 95% -74,847
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace roof insulation 0 11,796 sqft $15 $176,940
Estimating contingency 0 15% $26,541
Overhead & profit 0 30% $61,044
Design fees 0 10% $26,453
Project management 0 8% $23,278
Energy Costs
Electric Energy 1 - 25 -74,847 kWh $0.108 ($126,893)
Net Present Worth $187,400
Wrangell High School 29 Energy Audit (December 2011)
Appendix B
Energy and Utility Data
Wrangell High School 30 Energy Audit (December 2011)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Wrangell High School
ELECTRIC RATE
Electricity ($ / kWh )Block Rate
1st Block 70,000 $0.107
2nd Block $0.103
Customer Charge $13.50
ELECTRICAL CONSUMPTION AND DEMAND
2007 2008 2009 2010
kWh kWh kWh kWh
Jan 46,704 39,840 38,360 35,640 40,136
Feb 39,480 37,150 34,320 35,040 36,498
Mar 37,200 36,410 33,720 34,440 35,443
Apr 39,000 35,520 33,600 32,640 35,190
May 37,560 27,120 29,040 28,920 30,660
Jun 20,040 18,600 15,360 13,800 16,950
Jul 18,720 18,120 15,240 15,840 16,980
Aug 16,680 24,960 21,840 22,800 21,570
Sep 33,480 34,860 32,040 32,310 33,173
Oct 42,360 36,720 36,480 34,640 37,550
Nov 37,350 32,400 35,640 33,240 34,658
Dec 38,010 36,520 33,480 34,440 35,613
Total 406,584 378,220 359,120 353,750 374,419
Average 33,882 31,518 29,927 29,479 31,202
ELECTRIC BILLING DETAILS
Month Energy Total Energy Total % Change
Jan $4,105 $4,118 $4,295 $4,308 4.6%
Feb $3,672 $3,686 $3,905 $3,919 6.3%
Mar $3,608 $3,622 $3,792 $3,806 5.1%
Apr $3,595 $3,609 $3,765 $3,779 4.7%
May $3,107 $3,121 $3,281 $3,294 5.6%
Jun $1,644 $1,657 $1,814 $1,827 10.3%
Jul $1,631 $1,644 $1,817 $1,830 11.3%
Aug $2,337 $2,350 $2,308 $2,321 -1.2%
Sep $3,428 $3,442 $3,549 $3,563 3.5%
Oct $3,903 $3,917 $4,018 $4,031 2.9%
Nov $3,813 $3,827 $3,708 $3,722 -2.7%
Dec $3,582 $3,596 $3,811 $3,824 6.3%
Total $ 38,426 $ 38,588 $ 40,063 $ 40,225 4.2%
Average $ 3,202 $ 3,216 $ 3,339 $ 3,352 4.2%
Cost ($/kWh) $0.107 $0.114 5.8%
2009 2010
Electrical costs are based on the current electric rates.
Large Power Interruptible
Month Average
Wrangell High School 31 Energy Audit (December 2011)
Alaska Energy Engineering LLC Annual Electric Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Wrangell High School
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
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
$ 500
$ 1,000
$ 1,500
$ 2,000
$ 2,500
$ 3,000
$ 3,500
$ 4,000
$ 4,500
$ 5,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Cost (USD)Month of the Year
Electric Cost Breakdown
2010
Wrangell High School 32 Energy Audit (December 2011)
Alaska Energy Engineering LLC Annual Fuel Oil Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Wrangell High School
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
Year Fuel Oil
2,007 21,974
2,008 24,452
2,009 25,355
2,010 24,249
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
0
5,000
10,000
15,000
20,000
25,000
30,000
2007 2008 2009 2010 Degree DaysGallons of Fuel OilYear
Annual Fuel Oil Use
Fuel Oil
Degree Days
Wrangell High School 33 Energy Audit (December 2011)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Annual Energy Consumption and Cost
Energy Cost $/MMBtu Area ECI EUI
Fuel Oil $3.70 $38.16 58,096 $2.26 79
Electricity $0.114 $35.08
Source Cost
Electricity 374,419 kWh $42,600 1,300 28%
Fuel Oil 24,008 Gallons $88,800 3,300 72%
Totals $131,400 4,600 100%
Annual Energy Consumption and Cost
Consumption Energy, MMBtu
$33.00
$34.00
$35.00
$36.00
$37.00
$38.00
$39.00
Fuel Oil ElectricityCost $ / MMBtuCost of Heat Comparison
Wrangell High School 34 Energy Audit (December 2011)
Appendix C
Equipment Data
Wrangell High School 35 Energy Audit (December 2011)
MotorUnit IDLocationFunction Make Model Capacity HP / Volts / RPM / Effic NotesB 1 Boiler Room Fuel Oil BoilerWeil McLain 16863350 MBTUB 2 Boiler Room Fuel Oil BoilerWeil McLain 16863350 MBTUEB 1 Boiler Room Electric BoilerPrecision PCW3-3600-480-160 1260 MBTU 480 V/ 360 KWEB 2 Boiler Room Electric BoilerPrecision PCW3-3600-480-160 1260 MBTU 480 V/ 360 KWP 1 Boiler Room Boiler Circulation PumpTACO F14007E5GAJIL0A10 HP/ 208 V/ 1770 RPM/ 82%P2 Boiler Room Boiler Circulation PumpTACO F14007E5GAJIL0A10 HP/ 208 V/ 1770 RPM/ 82%P 6 Boiler Room Domestic Hot Water Heating TACO 0010-F31/8 HP/ 115 VHWRP 1 Boiler Room Dom. Hot H2O Recirculation Pump TACO 113-B41/8 HP/ 115 V/ 1725 RPMHWRP 2 Mechanical Room 255 Dom. Hot H2O Recirculation PumpAC 1 Boiler Room Control Air Compression Quincy FFJ-3252 HP/ 208 V/ 1725 RPM/ 71%SF 1 Boiler Room First Floor VentPACE A30 AFS113800 cfm 10 HP/ 208 V/ 1750 RPM/ 85.5%SF 2 Mechanical Room 218 Second Floor VentPACE A30 AFS113300 cfm 10 HP/ 208 V/ 1750 RPM/ 85.5%SF 3 Mechanical Room 409 Gym 304 VentPACE A33 AFS116500 cfm 7.5 HP/ 208V/ 1750 RPM/ 88.5%SF 4 Mechanical Room 255 Gym Locker VentPACE U-30 AF7000 cfm 5 HP/ 208 V/ 1745 RPM/ 86.5%SF 8 Mechanical Room 409 Commons Area VentPACE A 18 AFS1 5500 cfm 3 HP/ 208 V/ 1750 RPM/ 85.5%SF 9 Mechanical Room 406 Music Area VentPACE U18B2600 cfm 1.5 HP/ 208 V/ 1745 RPM/ 86%RF 1 Boiler Room First Floor VentPACE B-18 AFS1 10850 cfm 5 HP/ 208 V/ 1750 RPM/ 87%RF 2 Fan Room 238 Art Room 129PACE U-11 FC1050 cfm 1/2 HP/ 115 V/1725 RPM/62%RF 3 Fan Room 238 Dust Room 130PACE U-12B11150 cfm 1/2 HP/ 115 V/1725 RPM/62%RF 4 Mechanical Room 213 Second FloorPACE B-18AFS18100 cfm 3 HP/ 208 V/ 1750 RPM/ 86%RF 5 Fan Room 238 Science Room 220 Exhaust PACE U-13FC1460 cfm 1/2 HP/ 115 V/1725 RPM/62%Wrangell High School - Major Equipment InventoryWrangell High School 36 Energy Audit (December 2011)
MotorUnit IDLocationFunction Make Model Capacity HP / Volts / RPM / Effic NotesWrangell High School - Major Equipment InventoryRF 6 Fan Room 238 Science Room 222 Exhaust PACE U-12FC1250 cfm 1/2 HP/ 115 V/1725 RPM/62%RF 7 Fan Room 238 Dark Room ExhaustPACE U-6FC240 cfm 1/6 HP/ 115 VRF 9 Mechanical Room 406 Music Room ExhaustPACE U-18B2600 cfm 1 HP/ 208 V/ 1745 RPM/ 84%RF 10 Mechanical Room 409 Commons ExhaustPACE U-22AF4400 cfm 1.5 HP/ 208 V/ 1750 RPM/ 84%RF 11 Mechanical Room 409 Gym 304 ExhaustPACE 40 SWSI AF 13600 cfm 5 HP/ 208 V/ 1745 RPM/ 86.5%RF 12 Mechanical Room 255 Gym Locker Room Exhaust PACE A-20 AFSI 5000 cfm 2 HP/ 208 V/ 1745 RPM/ 84%EF 1 Fan Room 238 ToiletsPACE U12-B1930 cfm 1/4 HP/ 115 V/ 1725 RPM/47%EF 2 Kiln Room 131 Kiln Room 131Jenn Air B1-CW250 cfm 1/40 HP/ 115 VEF 3 RoofPaint Spray BoothGreenheck Cube 10-31170 cfm 1/2 HP/ 115 V/1725 RPM/62%EF 4 RoofKitchen Hood 103Greenheck Cube 14-51625 cfm 1/2 HP/ 115 V/1725 RPM/62%EF 5 Fan Room 238 Storage Room 221PACE U-9FC750 cfm 1/3 HP/ 115 V/1725 RPM/60%EF 6 Fan Room 238 Fume Hood Storage 221PACE U-9FC670 cfm 1/2 HP/ 115 V/ 1750 RPMEF 7 Fan Room 238 Fume Hood Science 220PACE U-11FC1100 cfm 1/2 HP/ 115 V/ 1750 RPMEF 8 Boiler Room Boiler RoomPACE U-11 FC1000 cfm 1/4 HP/ 115 V/47%EF 9 Science 222 Animal Cages Science 222 PACE DD150 T-V 100 cfm 1/50 HP/ 115 VEF 10 Mechanical Room 409 Commons Toilet Exhaust PACE U-13F600 cfm 1/2 HP/ 115 V/1725 RPM/62%DHWT 1 Boiler Room Domestic Hot WaterState Select E5652DDRT 50 gallon 4500 Watts / 240 V/ 90% Not in serviceDHWT 2 Boiler Room Domestic Hot WaterAmtrol WH580ZCDW 80 gallon indirect water heaterDHWT 3Domestic Hot WaterJass 120 DW120 gallon indirect water heaterDHWT 4Domestic Hot WaterJass 121 DW121 gallon indirect water heaterDHWT 5Domestic Hot WaterJass 122 DW122 gallon indirect water heater
Wrangell High School 37 Energy Audit (December 2011)
MotorUnit IDLocationFunction Make Model Capacity HP / Volts / RPM / Effic NotesWrangell High School - Major Equipment InventoryDHWT 6Domestic Hot WaterJass 123 DW123 gallon indirect water heaterEF 11 Mechanical Room 410 Gym Storage 412PACE U-13F1500 cfm 1/2 HP/ 115 V/1725 RPM/62%EF 12 Mechanical Room 255 Gym LockerPACE SCF-85AMI 1060 cfm 1/2 HP/ 115 V/1725 RPM/62%EB 1 HRPBoiler Room Heating Return PumpTACO 24-00-701/2 HP/ 115 V/ 3450 RPM/62%EB 2 Boiler Room Heating Return PumpTACO 24-00-701/2 HP/ 115 V/ 3450 RPM/62%KitchenRefrigeratorHobant Q1115 V/ 7.3 AKitchenFreezerHobant QF1115 V/ 12 AKitchenStoveno dataKitchenDishwasherJacksonKitchenOvenVolcan VC4ED1205 KWKitchenRefrigeratorTRUE T-231/3 HP compressorWrangell High School 38 Energy Audit (December 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
PSI Per square inch
PSIG Per square inch gage
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
Wrangell High School 39 Energy Audit (December 2011)