HomeMy WebLinkAboutSEA-AEE-Wrangell Pool 2012-EE
Wrangell Pool
City of Wrangell – Parks and Recreation Department
Funded by:
Final Report
November 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 14
Section 5: Methodology 16
Appendix A: Energy and Life Cycle Cost Analysis 19
Appendix B: Utility and Energy Data 25
Appendix C: Equipment Data 30
Appendix D: Abbreviations 32
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 Pool 1 Energy Audit (November 2011)
Section 1
Executive Summary
An energy audit of the Wrangell Pool 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 Pool is a 21,000 square foot building that contains commons, offices, a weight room, a
racquetball court, a pool, locker rooms, storage, and mechanical support spaces.
Building Assessment
The following summarizes our assessment of the building.
Envelope
The Pool building envelope is simple in design and provides the opportunity to achieve a very energy
efficient shell without great expense or effort. The design decision to incorporate arctic entries and
minimal windows further improves the buildings performance. Unfortunately several envelope
components are substandard and greatly reduce the building’s energy efficiency.
IRMA Roof: One of the least energy efficient envelope issues is the Inverted Roof Membrane
Assembly (IRMA) on the racquetball court and surrounding flat roof spaces. This style roof
typically has an initial waterproof membrane, then a layer of foam insulation, then a fabric cloth
cover then roofing pavers. The building has a base layer of foam that is 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 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.
Recommendations for replacement of these roofs with a tapered roof system buildup to optimum
insulation levels supported by a life cycle cost analysis are provided Section 3, Energy Efficiency
Measures.
Pool Roof: The roof above the pool space has only 5” of rigid foam and an R-20 insulation value
for a space that is heated to 84°F year round. Optimum ceiling insulation values in the climate of
Wrangell are approximately an R-60. The result is that on the coldest of days the pool roof is so
under-insulated that the interior roof deck temperature is cold enough to create frost, with
subsequent condensation issues.
Wrangell Pool 2 Energy Audit (November 2011)
Pool Walls: The west wall and the gable end east wall are constructed of a concrete block wall
with 4” metal studs on the exterior surface, 4” rigid batt insulation between the studs, and exterior
wood siding. The insulation value of the concrete block is R-1, and 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, the
result is that the overall insulation value of the wall is very low at R-5. The optimum energy
efficiency for a newly constructed wall is R-30.
Deteriorating Siding: The west wall siding is showing signs of wood root at the joints and at the
base of the building. The pool building is in worse shape than the high school due to an
apparently more comprehensive maintenance program on the school buildings.
Exterior Doors: Exterior doors are not thermally broken. Future exterior door replacement
selection should include this feature. Weather stripping is in poor condition and should be
replaced.
Heating & Ventilation Systems
The building is heated by the high school boiler plant, which consists of two electric boilers that are
supplemented by two fuel oil boilers. The heating units consist of nine air handling unit systems, fan
coil units, domestic hot water heating systems, and perimeter hydronic systems throughout the pool
building.
The control system for the high school and pool complex originally used pneumatic controllers. The
high school has since upgraded their controls to electronic units and incorporated a DDC system. The
pool building continues to use the pneumatic controllers, many of which have failed or need
replacement. The pneumatics also limit the use of optimal control strategies that are possible with
DDC controls. In addition, the corrosive environment of the pool building has rendered several of the
damper units completely inoperable. It is highly recommended that the control system be upgraded to
DDC controls.
There is a significant amount of damaged duct insulation throughout the building. Energy will be
saved if the duct insulation is repaired.
The rest of the systems are 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 primarily consists of T8 fluorescent fixtures throughout the spaces and metal halide
pendant fixtures above the pool. Exterior lighting primarily consists of high pressure sodium and
metal halide lighting. Because the additional heat produced by the metal halide fixtures above the
pool is beneficial for heating the building with relatively low cost hydroelectric power, no interior
lighting modifications are recommended within this report.
Wrangell Pool 3 Energy Audit (November 2011)
Summary
It is the assessment of the energy audit team that the majority of the building energy losses are due to
a lack of sufficient roof insulation as a result of the IRMA systems, the design of the pool building
west wall insulation package, and the failing pneumatic control system.
It should be noted that the corrosion rate of much of the pool water treatment infrastructure seems
excessive and very aggressive. This has been the case at all of the pools we have audited that have
shifted from gaseous chlorine to salt produced chlorine. This is most likely due to the high
concentration of salt in the pool when salt is added. We recommend investigating an alternate mixing
system that injects salt at a lower concentration into the pool water.
Energy Efficiency Measures (EEMs)
All buildings have opportunities to improve their energy efficiency. The energy audit revealed several
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: Install Return Tank Cover
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-3: Replace Aerators $1,000 $0 ($100,100) ($99,100) 100.1
EEM-4: Upgrade Exterior Lighting $400 ($1,900) ($10,100) ($11,600) 30.0
Medium Priority
EEM-5: Optimize SF-5 (Pool Locker) System $48,000 $5,100 ($135,200) ($82,100) 2.7
EEM-6: Optimize SF-7 (Pool Mechanical) System $65,700 $5,100 ($120,000) ($49,200) 1.7
EEM-7: Install VFDs on Pool Pumps $44,400 $1,700 ($75,600) ($29,500) 1.7
EEM-8: Optimize SF-6 (Natatorium) System $83,500 $6,800 ($136,800) ($46,500) 1.6
EEM-9: Increase Wall Insulation $35,700 $0 ($49,900) ($14,200) 1.4
Totals* $278,700 $16,800 ($627,700) ($332,200) 2.2
*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 Pool 4 Energy Audit (November 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 Pool 5 Energy Audit (November 2011)
Section 2
Introduction
This report presents the findings of an energy audit of the Wrangell Pool 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 Pool is a 21,000 square foot building that contains a lobby, offices, a weight room, a
racquetball court, a natatorium, locker rooms, storage, and mechanical support spaces.
The pool building is operated by 3 full-time and 15 part-time staff, and used by approximately 15
visitors per hour. The facility is scheduled in the following manner:
Pool 6:00 am – 8:30 pm (M W F)
10:00 am – 2:00 pm (T TH)
12:00 pm – 4:00 pm (Sat)
Weight Room/Racquetball 6:00 am – 8:30 pm (M W F)
8:00 am – 6:00 pm (T TH)
12:00 pm – 4:00 pm (Sat)
Building History
1985 – Original Construction
2011 – Electric Boiler Installation
Wrangell Pool 6 Energy Audit (November 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 shows historic energy use and cost prior to switching to electric heat in 2011.
Annual Energy Consumption and Cost
Source Consumption Cost Energy, MMBtu
Electricity 259,080 kWh $29,100 900 20%
Fuel Oil 26,363 Gallons $97,600 3,600 80%
Totals $126,700 4,500 100%
Electricity
This chart shows
electrical energy use
from 2007 to 2010. The
transition to electric
boilers was made in
2011 and data is not
available for the
increased electricity use
of the pool building.
The effective cost—
energy costs plus
demand charges—is
11.2¢ per kWh.
Wrangell Pool 7 Energy Audit (November 2011)
Fuel Oil
This chart shows
heating energy use
from 2007 to 2010 and
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 2011 due to switching to electric heat.
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 Pool 8 Energy Audit (November 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 pool building 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: Install Return Tank Cover
Purpose: The pool surge tank in the basement mechanical space is open to the room. The tank
loses heat and humidity to the room. Energy will be saved if a removable cover is
installed on the tank.
Scope: Install a tank cover over the pool surge tank in the basement mechanical space.
Wrangell Pool 9 Energy Audit (November 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-3: 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 ($5,710) ($5,710) $1,000 $0 ($100,100) ($99,100) 100.1
EEM-4: Upgrade Exterior Lighting
Purpose: The existing perimeter recessed lighting consists of high pressure sodium fixtures. These
fixture styles are less efficient than CFL lighting and the lamp life is much shorter.
Scope: Replace these existing exterior lights with CFL lights.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($110) ($570) ($680) $400 ($1,900) ($10,100) ($11,600) 30.0
Wrangell Pool 10 Energy Audit (November 2011)
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-5: Optimize SF-5 (Pool Lockers) System
Purpose: The SF-5 system ventilates the pool locker rooms. The control sequence modulates the
mixing dampers between 50°F and 60°F, which brings in much more ventilation air than
required to make-up the exhaust air. Energy will be saved if the controls are replaced
with a DDC system with a 62°F mixed air setpoint that is overridden when space
humidity is high.
Scope: Optimize SF-5 and retro-commission the system.
- Replace the pneumatic controls with DDC controls
- Modulate the mixing dampers to maintain 62°F mixed air temperature with humidity
control.
- Modulate the EAD from the building pressure sensor
Operating Energy Total Investment Operating Energy Total SIR
$300 ($7,710) ($7,410) $48,000 $5,100 ($135,200) ($82,100) 2.7
EEM-6: Optimize SF-7 (Pool Mechanical) System
Purpose: The SF-7 system ventilates the pool mechanical space. The mixing dampers are corroded
and inoperable. The system was designed to maintain 50°F mixed air temperature to
dehumidify the space. If the surge tank is covered (EEM-2), the dehumidification
requirement will drop substantially. Energy will be saved if the controls are replaced with
a DDC system and the outside air is modulated with the humidity level in the space.
Scope: Optimize SF-7 and retro-commission the system.
- Replace the mixing dampers
- Replace the pneumatic controls with DDC controls
- Modulate the mixing dampers to maintain humidity in the space.
Operating Energy Total Investment Operating Energy Total SIR
$300 ($6,850) ($6,550) $65,700 $5,100 ($120,000) ($49,200) 1.7
EEM-7: Install VFDs on Pool Pumps
Purpose: The pool utilizes two 15-HP circulation pumps to circulate, heat, and filter the water.
Energy will be saved if the flow rate is reduced during off hours.
Scope: Install VFDs on the two 15-HP pool circulation pumps and controls to modulate them
with operating hours. Another option is to install a smaller pump for off hours.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$100 ($4,310) ($4,210) $44,400 $1,700 ($75,600) ($29,500) 1.7
Wrangell Pool 11 Energy Audit (November 2011)
EEM-8: Optimize SF-6 (Natatorium) System
Purpose: The SF-6 system ventilates the natatorium with a constant flow of outside air for
dehumidification. The pool staff uses a pool cover when the pool is not in use to reduce
evaporation and heat loss from the pool. The cover also decreases the dehumidification
requirement. Energy will be saved if the controls are replaced with a DDC system and
VFDs are installed on SF-6 and RF-8 so both the supply air flow and the outside air flow
are reduced during unoccupied periods when humidity levels are significantly lower.
Scope: Optimize SF-6 and retro-commission the system.
- Replace pneumatic controls with DDC
- Control outside air from humidity sensor
- Remove pump P-14 body from piping
- Change SAT control to modulate dampers and automatic valve sequentially to
maintain pool temperature, with humidity sensor override
- Convert SF-6 and RF-8 to VAV. Reduce air flow at night when cover is on
- Modulate EAD from room pressure sensor
Operating Energy Total Investment Operating Energy Total SIR
$400 ($7,800) ($7,400) $83,500 $6,800 ($136,800) ($46,500) 1.6
EEM-9: Increase Wall Insulation
Purpose: The pool west and east gable end walls are constructed of concrete with metal stud
furring supporting the wood siding. The lack of a thermal break creates an R-5 assembly.
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 pool building promotes the use of exterior rigid insulation to
increase the wall insulation. However, the energy savings will not offset the cost of
replacing the siding. When the siding is replaced, 4” of rigid insulation should be added
to the wall assembly.
Scope: Install a minimum of 4” of exterior foam insulation around the perimeter of building at
the time the siding is replaced. This cost analysis does not include the siding costs.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($2,850) ($2,850) $35,700 $0 ($49,900) ($14,200) 1.4
Wrangell Pool 12 Energy Audit (November 2011)
LOW PRIORITY
Low priority EEMs do not offer a life cycle energy savings and are not recommended.
EEM-10: Upgrade Motors to Premium Efficiency
Purpose: The equipment inspection identified three motors that could be upgraded with premium
efficiency models to save energy. They are:
- SF-6 7.5 HP
- RF-8 5 HP
- RF-13 2 HP
Scope: Replace identified motors with premium efficiency motors. The analysis determined that
the existing motors are reasonably efficient and the energy savings will not offset the cost
of replacing them.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($150) ($150) $4,000 $0 ($2,600) $1,400 0.7
EEM-11: Replace Racquet Ball and Upper Entry Roof (2,444 sq ft from R10 to R46)
Purpose: The roof over the racquet ball court and upper entry includes a base layer of foam that is
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 IRMA roof system in this building with an 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 ($1,690) ($1,690) $73,800 $0 ($29,700) $44,100 0.4
Wrangell Pool 13 Energy Audit (November 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
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
West Wall 8” concrete block, 4” metal studs w/4” semi rigid batt, siding R-5 R-26
Cathedral Roof 24” o.c. trusses w/ 3” wood & 5” rigid insulation R-20 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 12” 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 primary heat sources for the building are two electric boilers that provide heat to three air
handling unit systems, fan coil units, and perimeter hydronic systems. Two fuel oil boilers provide
backup heat. The heating system has the following pumps:
P-1 & P-2 are the building 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-8 is a domestic hot water heating pump.
P-13 is for the heating coil in the pool locker.
P-15 is the pool water heater pump.
P-16 is the pool circulation pump.
P-17 is the pool circulation pump.
HWRP-2 is the domestic hot water recirculating pump for the gymnasium and pool building.
HWRP-3 is the pool domestic hot water recirculation pump.
Wrangell Pool 14 Energy Audit (November 2011)
Ventilation Systems
Area Fan System Description
Pool Lockers SF-5 7,300 cfm 5 HP constant volume air handling unit consisting
of a mixing box, filter section, primary heating coil, and
supply fan
Pool Areas SF-6 13,000 cfm 7.5 HP constant volume air handling unit
consisting of a mixing box, filter section, primary heating coil,
and supply fan
Mechanical Room 100 SF-7 3/4 HP constant volume air handling unit consisting of a
mixing box, filter section, primary heating coil, and supply fan
Pool Areas RF-8 14,000 cfm 5 HP constant volume fan
Pool Locker Areas RF-13 2 HP constant volume fan
Pool Locker Areas EF-13 ½ HP constant volume exhaust air fan
Gas Storage 207 EF-14 ¼ HP constant volume exhaust air fan
Domestic Hot Water System
The gym and pool locker rooms are served by four JASS 120-gallon indirect hot water heaters.
Automatic Control System
The building has a pneumatic automatic control system. As discussed in the Executive Summary, as
soon as funding is available the system should be upgraded to a DDC system similar to that in the
high school to reduce operational and utility costs while improving space conditioning.
Lighting
Interior lighting consists primarily of T8 fluorescent fixtures throughout the spaces and metal halide
pendant fixtures above the pool. Exterior lighting consists primarily of high pressure sodium and
metal halide lighting. Because the additional heat produced by the metal halide fixtures above the
pool is beneficial within the building envelope in the climate of Wrangell with relatively low cost
hydroelectric power, no interior lighting modifications are recommended within this report.
Wrangell Pool 15 Energy Audit (November 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 Pool 16 Energy Audit (November 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 $3.70 per gallon for a seasonally adjusted blend of #1 and #2 fuel oil. The
analysis is based on 6% fuel oil inflation which has been the average for the past 20-years.
Electricity
Electricity is supplied by Wrangell Municipal Light & Power. The building is billed for electricity
under their Large Commercial rate.
Large Power Interruptible
Electricity ($ / kWh ) Block Rate
1st Block 70,000 $0.107
2nd Block $0.103
Customer Charge $13.50
Wrangell Pool 17 Energy Audit (November 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 $0.112/kWh
General Inflation Rate 2% Electricity Inflation 2%
Fuel Oil Cost (2012) $3.70/gal Fuel Oil Inflation 6%
Wrangell Pool 18 Energy Audit (November 2011)
Appendix A
Energy and Life Cycle Cost Analysis
Wrangell Pool 19 Energy Audit (November 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 $0.00 6% $0.00
Electricity $/kWh (2011)$/kW (2011)Inflation $/kWh (2012)$/kW (2012)
w/ Demand Charges $0.107 $0.00 2% $0.109 $0.00
w/o Demand Charges $0.107 -2% $0.109 -
EEM-3: Replace Aerators
Energy Analysis
Fixture Existing Proposed Uses/day Days Water,Gals % HW kBTU kWh
Showerhead 20.0 10.0 100 312 -312,000 80% -166,533 -51,377
Lavatories 0.3 0.2 100 312 -5,616 80% -2,998 -925
-317,616 -52,302
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace lavatory aerators 0 9 ea $35 $315
Replace showerhead 0 20 ea $35 $700
Energy Costs
Electric Energy (Effective Cost)1 - 25 -52,302 kWh $0.109 ($100,053)
Net Present Worth ($99,000)
EEM-4: Upgrade Exterior Lighting
Energy Analysis
Type # Fixtures Lamp Lamp, watts Fixture Watts Lamp Lamp, watts Fixture Watts Savings, kWh
WallPak 15 MH 70 95 CFL -15 -5,256
Lamp Replacement
Type # Fixtures Lamp # Lamps Life, hrs Lamps//yr $ / lamp $ / Replace
Canopy 15 MH -1 12,000 -5.48 $42 $20
Canopy 15 CFL 1 8,000 8.21 $8 $20
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace WallPak: 70 watt MH with LED 0 15 LS $25 $375
Annual Costs
Existing lamp replacement, 70 watt MH 1 - 25 -5.48 lamps $62.00 ($5,780)
LED board replacement, 40 watts 1 - 25 8.21 lamps $28.00 $3,915
Energy Costs
Electric Energy 1 - 25 -5,256 kWh $0.109 ($10,055)
Net Present Worth ($11,500)
Gallons per Use
Existing Replacement
Wrangell Pool 20 Energy Audit (November 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-5: Optimize SF-5 (Pool Locker) System
Energy Analysis
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-5 Existing -7,300 51.7 70 -144 3,500 -504,970 95% -155,788
Optimized 7,300 60 70 79 3,500 275,940 95%85,130
-229,030 -70,658
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace controls with DDC 0 1 ea $25,000 $25,000
Commissioning 0 1 ea $2,000 $2,000
Estimating contingency 0 15%$4,050
Overhead & profit 0 30%$9,315
Design fees 0 10%$4,037
Project management 0 8%$3,552
Annual Costs
DDC Maintenance 1 - 25 1 LS $300.00 $5,108
Energy Costs
Electric Energy 1 - 25 -70,658 kWh $0.109 ($135,168)
Net Present Worth ($82,100)
EEM-6: Optimize SF-7 (Pool Mechanical) System
Energy Analysis
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-7 Existing -2,500 51.4 70 -50 8,760 -439,927 95% -135,721
Optimized 2,500 60 70 27 8,760 236,520 95%72,968
-203,407 -62,753
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace mixing dampers 0 1 ea $10,000 $10,000
Commissioning 0 1 ea $2,000 $2,000
Replace controls with DDC 0 1 ea $25,000 $25,000
Estimating contingency 0 15%$5,550
Overhead & profit 0 30% $12,765
Design fees 0 10%$5,532
Project management 0 8%$4,868
Annual Costs
DDC Maintenance 1 - 25 1 LS $300.00 $5,108
Energy Costs
Electric Energy 1 - 25 -62,753 kWh $0.109 ($120,045)
Net Present Worth ($49,200)
Wrangell Pool 21 Energy Audit (November 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-7: Install VFDs on Pool Pumps
Energy Analysis
Mode GPH Head η pump BHP η motor kW Hours kWh
Existing -400 60 65% -12.5 93% -10.0 8,760 -87,771
Proposed 400 60 65% 12.5 93% 10.0 3,500 35,069
200 30 65% 3.1 93% 2.5 5,260 13,176
-39,527
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install 15 HP VFD 0 2 ea $10,000 $20,000
Time clock controller 0 1 ea $5,000 $5,000
Estimating contingency 0 15%$3,750
Overhead & profit 0 30%$8,625
Design fees 0 10%$3,738
Project management 0 8%$3,289
Annual Costs
VFD maintenance 1 - 25 1 ea $100.00 $1,703
Energy Costs
Electric Energy 1 - 25 -39,527 kWh $0.109 ($75,615)
Net Present Worth ($29,500)
EEM-8: Optimize SF-6 (Natatorium) System
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
SF-6 Unoccupied -13,000 1.75 55%-7 91%-5 5,260 -28,062
Optimized 8,000 1.25 55%3 91%2 5,260 12,335
RF-8 Unoccupied -14,000 0.75 55%-3 89%-3 5,260 -13,243
Optimized 9,000 0.50 55%1 89%1 5,260 5,675
-4 -23,294
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler kWh
SF-6 Existing -13,000 75.2 80 -67 5,260 -354,482 95% -109,361
Optimized 8,000 77.3 80 23 5,260 122,705 95%37,856
-231,777 -71,505
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace control system 0 1 ea $30,000 $30,000
Commissioning 0 1 ea $2,000 $2,000
Install VFD 0 2 LS $7,500 $15,000
Estimating contingency 0 15%$7,050
Overhead & profit 0 30% $16,215
Design fees 0 10%$7,027
Project management 0 8%$6,183
Annual Costs
DDC Maintenance 1 - 25 1 LS $400.00 $6,811
Energy Costs
Electric Energy 1 - 25 -71,505 kWh $0.109 ($136,788)
Net Present Worth ($46,500)
Wrangell Pool 22 Energy Audit (November 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-9: Increase Wall Insulation
Energy Analysis
Component Area R,exist R,new ΔT MBH kBtu η boiler kWh
Wall 2,010 5 25 30 -9.6 -84,516 95% -26,074
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install wall insulation 0 2,010 sqft $10 $20,100
Estimating contingency 0 15%$3,015
Overhead & profit 0 30%$6,935
Design fees 0 10%$3,005
Project management 0 8%$2,644
Annual Costs
1 - 25 $60.00 $0
1 - 25 $60.00 $0
1 - 25 $50.00 $0
Energy Costs
Electric Energy 1 - 25 -26,074 kWh $0.109 ($49,879)
Net Present Worth ($14,200)
EEM-10: Upgrade Motors to Premium Efficiency
Energy Analysis
Equip Number HP ηold ηnew kW Hours kWh
RF-13 1 2 84.0% 86.5% -0.04 3,500 -131
RF-8 1 5 86.5% 89.5% -0.11 3,500 -392
SF-6 1 7.5 87.5% 91.7% -0.23 3,500 -822
-0.4 -1,345
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs HP
Replace motor 2 0 1 LS 970 $970
Replace motor 5 0 1 LS 1,290 $1,290
Replace motor 7.5 0 1 LS 1,690 $1,690
Annual Costs
1 - 25 $60.00 $0
1 - 25 $60.00 $0
1 - 25 $50.00 $0
Energy Costs
Electric Energy 1 - 25 -1,345 kWh $0.109 ($2,572)
Net Present Worth $1,400
Wrangell Pool 23 Energy Audit (November 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-11: Increase Roof Insulation
Energy Analysis
Component Area R,exist R,new ΔT MBH kBtu η boiler kWh
Roof 2,444 10 46 30 -5.7 -50,266 95% -15,507
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Increase roof insulation 0 2,444 sqft $17 $41,548
Estimating contingency 0 15%$6,232
Overhead & profit 0 30% $14,334
Design fees 0 10%$6,211
Project management 0 8%$5,466
Energy Costs
Electric Energy 1 - 25 -15,507 kWh $0.109 ($29,665)
Net Present Worth $44,100
Wrangell Pool 24 Energy Audit (November 2011)
Appendix B
Energy and Utility Data
Wrangell Pool 25 Energy Audit (November 2011)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Wrangell Pool
ELECTRIC RATE
Electricity ($ / kWh )Block Rate
1st Block 70,000 $0.107
2nd Block $0.103
Customer Charge $13.50
ELECTRICAL CONSUMPTION AND DEMAND
2008 2009 2010 2011
kWh kWh kWh kWh
Jan 25,920 23,280 22,440 21,360 23,250
Feb 25,080 20,400 19,920 20,280 21,420
Mar 23,760 21,960 21,960 23,760 22,860
Apr 23,280 22,080 21,120 22,920 22,350
May 22,800 23,280 21,240 20,880 22,050
Jun 21,960 20,640 20,760 23,040 21,600
Jul 22,920 21,720 22,320 23,040 22,500
Aug 16,560 16,320 18,960 21,000 18,210
Sep 21,720 22,440 21,480 24,960 22,650
Oct 21,840 22,560 22,440 27,360 23,550
Nov 21,120 20,040 21,480 24,600 21,810
Dec 21,960 21,720 23,640 22,440
Total 268,920 256,440 257,760 253,200 259,080
Average 22,410 21,370 21,480 23,018 22,070
ELECTRIC BILLING DETAILS
Month Energy Total Energy Total % Change
Jan $2,401 $2,415 $2,488 $2,501 3.6%
Feb $2,131 $2,145 $2,292 $2,305 7.5%
Mar $2,350 $2,363 $2,446 $2,460 4.1%
Apr $2,260 $2,273 $2,391 $2,405 5.8%
May $2,273 $2,286 $2,359 $2,373 3.8%
Jun $2,221 $2,235 $2,311 $2,325 4.0%
Jul $2,388 $2,402 $2,408 $2,421 0.8%
Aug $2,029 $2,042 $1,948 $1,962 -3.9%
Sep $2,298 $2,312 $2,424 $2,437 5.4%
Oct $2,401 $2,415 $2,520 $2,533 4.9%
Nov $2,298 $2,312 $2,334 $2,347 1.5%
Dec $2,529 $2,543 $2,401 $2,415 -5.0%
Total $ 27,580 $ 27,742 $ 28,322 $ 28,484 2.7%
Average $ 2,298 $ 2,312 $ 2,360 $ 2,374 2.7%
Cost ($/kWh) $0.108 $0.112 4.5%
2010 2011
Electrical costs are based on the current electric rates.
Large Power Interruptible
Month Average
Wrangell Pool 26 Energy Audit (November 2011)
Alaska Energy Engineering LLC Annual Electric Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Wrangell Pool
0
5,000
10,000
15,000
20,000
25,000
30,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Use (kWh)Month of the Year
Electric Use History
2008
2009
2010
2011
$ 0
$ 500
$ 1,000
$ 1,500
$ 2,000
$ 2,500
$ 3,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Cost (USD)Month of the Year
Electric Cost Breakdown
2010
Wrangell Pool 27 Energy Audit (November 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 Pool
#DIV/0!
#DIV/0!
#DIV/0!
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Year Fuel Oil Degree Days
2,008 29,427 7,385
2,009 23,516 7,538
2,010 26,145 7,390
2,011 3,380 7,000
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
2008 2009 2010 2011 Degree DaysGallons of Fuel OilYear
Annual Fuel Oil Use
Fuel Oil
Degree Days
Wrangell Pool 28 Energy Audit (November 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 $38.17 21,000 $6.03 214
Electricity $0.112 $34.71
Source Cost
Electricity 259,080 kWh $29,100 900 20%
Fuel Oil 26,363 Gallons $97,600 3,600 80%
Totals $126,700 4,500 100%
Annual Energy Consumption and Cost
Consumption Energy, MMBtu
Wrangell Pool 29 Energy Audit (November 2011)
Appendix C
Equipment Data
Wrangell Pool 30 Energy Audit (November 2011)
MotorUnit ID Location Function Make Model Capacity HP / Volts / RPM / Effic NotesP 8 Mechanical Room 100 Domestic Hot Water Pump B+G 1B10001/3 HP/ 115 V/ 1725 RPM/77%P 13 Mechanical Room 209 Heating Coil Pool Locker B+G 11-2AA41-4BE1/3 HP/ 115 V/ 1725 RPM/77%P 15 Mechanical Room 100 Pool Water Heater Pump TACO 0012-4F1/8 HP/ 115 V/ 3250 RPMP 16 Mechanical Room 100 Pool Circulation Pump PACO 11-40957-122L1115 HP/ 208 V/ 1760 RPM/ 91%P 17 Mechanical Room 100 Pool Circulation Pump PACO 11-40957-122L1115 HP/ 208 V/ 1760 RPM/ 91%HWRP 3 Mechanical Room 100 Pool Domestic Hot Water TACO 06-BT4-11/4 HP/ 115 V/ 3250 RPM/74%SF 5 Mechanical Room 209 Pool Locker Vent PACE A22 AFS1 7300 5 HP/ 208 V/ 1755 RPM/ 89.5% SF 6 Mechanical Room 303 Pool AreasPACE A27 AFSF 13000 7.5 HP/ 208 V/ 1760 RPM/ 87.5%SF 7 Mechanical Room 100 Mechanical Room 100 PACE 85-51-03/4 HP/ 208 V/ 1725 RPM/82%RF 8 Mechanical Room 303 Pool Area VentPACE 8A27 AFS1 14000 5 HP/ 208 V/ 1725 RPM/ 86.5%RF 13 Mechanical Room 209 Pool Locker Vent PACE U24-AF2 HP/ 208 V/ 1745 RPM/ 84%EF 13 Mechanical Room 209 Pool Locker Exhaust PACE U12-F1/2 HP/ 208 V/ 1725 RPM/78.5%EF 14 RoofGas Storage 207 Exhaust Greenheck Cube 10-41/4 HP/ 115 V/74%Major Equipment InventoryWrangell PoolWrangell Pool 31 Energy Audit (November 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 Pool 32 Energy Audit (November 2011)