HomeMy WebLinkAboutSEA-AEE-JNU Treadwell Arena 2012-EE
Treadwell Ice Arena
City and Borough of Juneau
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 8
Section 4: Description of Systems 13
Section 5: Methodology 15
Appendix A: Energy and Life Cycle Cost Analysis 18
Appendix B: Energy and Utility Data 25
Appendix C: Equipment Data 32
Appendix D: Abbreviations 35
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
Treadwell Ice Arena 1 Energy Audit (December 2011)
Section 1
Executive Summary
An energy audit of the Treadwell Arena 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 Treadwell Arena is a 36,158 square foot building that contains offices, commons spaces, locker
rooms, restrooms, storage, a mezzanine, an ice skating rink and bleachers, and mechanical support
spaces.
Building Assessment
The following summarizes our assessment of the building.
Envelope
The building envelope appears to be well maintained and is providing good service. The exterior
walls and ceiling are fairly well insulated and a thermal break was intentionally installed in the ceiling
to aid in the performance of the ceiling insulation package. The exterior walls have an estimated
insulation value of R-20, and the ceiling is an estimated R-30.
It should be noted that the purpose of the arena ceiling insulation is to retain the cold air generated by
the ice rink. That is because, unlike the more energy efficient indoor skating rink designs that are
heated to 50°-60°F in an effort to optimize all of the energy cycles utilized within the building
envelope, the Treadwell Arena is intentionally unheated. The insulation of the interior framed walls
and ceilings of the offices, locker rooms, and restrooms is actually necessary to reduce heat loss from
these conditioned spaces to the interior of the building. The open skating area in the center of the
building has a constant temperature of just under 40°F whenever the rink has ice. This results in a
30°F temperature differential between the rink and the conditioned spaces. The year-round average
difference in temperature between these spaces and the interior skating rink area is actually larger
than the difference in temperature between these spaces and the exterior, even though the exterior
walls are more heavily insulated.
The ceiling insulation value for the offices, lockers, and restrooms is only R-20, where an R-46 would
be optimal. The interior wall insulation value for the offices, lockers, and restrooms is only R-12,
where an R-26 would be optimal. The insulation value for the interior conditioned spaces is
inadequate.
An evaluation to add insulation to these walls was performed and it did not show a positive return on
investment. This is not because the additional insulation isn’t needed. It is because the cost to install
the insulation after the building has already been constructed is too high. This is a design that will
result in excessive long-term operational costs—there was adequate space to install R-30 batt
insulation in the ceilings and R-21 batt in the walls.
The 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.
Treadwell Ice Arena 2 Energy Audit (December 2011)
Heating & Ventilation Systems
The building is heated by one fuel oil boiler that provides heat to three heat recovery ventilator
(HRV) unit systems, unit heaters, 5 indirect hot water heaters, and perimeter hydronic systems in the
conditioned spaces. The boiler system is in a dedicated mechanical space and the heating loop water
is delivered by piping that is physically attached to the inside walls of the building in such a manner
that it cannot expand or contract. Heating pipes have broken as a result of the non-expandable design.
The ventilation rates of the HRV systems are excessive much of the day when locker rooms are
lightly used. The result is an unnecessarily high heating oil consumption rate. The three HRV’s
deliver 7,140 cfm of conditioned outside air to the 6,150 square feet of offices, locker rooms, and
restrooms. This is 1.2 cfm/sqft whether the spaces are occupied or not. For the type and frequency of
use of those spaces, a system that can modulate the outside air with humidity levels will significantly
reduce the heating load on the boiler system.
The chiller system that is used for ice making currently utilizes a roof top condenser to dump the heat
generated from the ice making process outside of the building envelope. The chiller is a 70 ton unit.
Preliminary calculations show that the average rate of rejected heat is sufficient for supplying the
building heating load. If this heat were utilized within the building, it would essentially eliminate all
of the fuel oil consumption at the facility—over 15,000 gallons/year.
In an effort to maximize the ice quality at the arena, two propane dehumidifiers are operated to reduce
the relative humidity to between 45% and 55%. These units have a peak load of 253 MBH and 235
MBH each. If the ventilation rate of the interior heated spaces was reduced as mentioned above, the
heating load on the building would be reduced enough that not only could all of the heating demand
be carried by the chiller system, but a sizable portion of the dehumidifier systems could be too.
Although it sounds contradictory, more energy is used to condition and dehumidify the unheated
Treadwell Arena than would be used if the main space was heated to 50°-60°F. To take this one step
further, if the rink space was heated with refrigeration heat and the propane powered Zamboni was
replaced with a similar electric-powered model the Treadwell Arena could eliminate the use of fuel
oil and propane in the building and have the entire facility power by hydroelectricity. Currently
propane is used for both the Zamboni and the dehumidifiers.
Unfortunately, the existing design sets up a vicious energy consumption cycle. A propane powered
Zamboni exhausts water vapor and combustion pollutants such as CO, CO2, NO2 and combustion
particles into the building; many ice arena’s experience poor indoor air quality due to Zamboni
operation. We recommend that air quality monitoring be performed continuously for these pollutants
and that ventilation systems operate continuously, modulating with pollutant level, when the building
is occupied.
Not only does this reduce the air quality in the building for the occupants, it is the catalyst for the
cycle of conflicting energy demands. As the humidity goes up and hits the 55% setpoint, the propane-
powered dehumidifiers are automatically started. They run to try to maintain the humidity level
between 45% and 55%. As the exhaust air from the Zamboni concentrates in the arena, the CO2 levels
trigger the exhaust fans to bring in outside air to improve air quality for the occupants. The outside air
in Juneau is typically much higher in humidity than the desired humidity setpoints inside the arena.
Once the outside air is brought into the building, the humidity sensors then trigger the propane-
powered dehumidifiers to run once again. This cycle repeats itself every 20 minutes on hockey game
days when the Zamboni runs between each period. In addition to reducing utility costs for the arena,
the energy cost of operating the Zamboni would be reduced by shifting from propane power at an
estimated $1.10/use to electricity at $0.25/use.
Treadwell Ice Arena 3 Energy Audit (December 2011)
The remainder of the heating and ventilating systems appears 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.
Cooling Systems
The ice rink is maintained by a 70-ton CIMCO chilling unit that rejects the heat to a rooftop mounted
condenser unit. As mentioned, there is no recovery of the rejected heat.
Lighting
Interior lighting consists primarily of T8 fluorescent fixtures throughout the spaces and 1000-watt
metal halide pendant fixtures above the arena. The pendant fixtures are made with a special glass due
to the potential for impact by hockey pucks. Exterior lighting primarily consists of compact
fluorescent and metal halide lighting.
While more energy efficient fixtures are available that could deliver similar lighting intensity to the
arena, they do not have the necessary impact resistant housings and are not recommended due to
potential safety issues. Parking lot lighting and a portion of the building perimeter lights are not
powered from the Treadwell Arena electrical system, but are instead controlled by a photocell that is
located in Savikko Park. During the inspection these lights were still on at 10:30 am. The remainder
of the perimeter lighting is powered by the Treadwell Arena electrical system and the photocell for
that lighting circuit was operating properly.
Maintenance staff has replaced the exterior high pressure sodium lights with much more energy
efficient compact fluorescent lamps. They have also improved circuiting so the lobby lights can be
turned on without lighting half the ice rink.
Summary
It is the assessment of the energy audit team that the majority of the building energy losses are due to
insufficient insulation in interior walls of heated spaces and over-ventilation rates for those same
spaces. The greatest potential for reducing operational costs through energy efficiency measures
however is by utilizing the heat generated by the ice refrigeration system to heat the facility and
perform dehumidification.
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: De-Lamp Soft Drink Coolers
Treadwell Ice Arena 4 Energy Audit (December 2011)
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: Install Heating Pipe Insulation $200 $0 ($18,300) ($18,100) 91.5
EEM-4: Replace Aerators and Showerheads $1,100 $0 ($66,900) ($65,800) 60.8
EEM-5: Install Door in Rental Pass-through $1,800 ($900) ($13,000) ($12,100) 7.7
EEM-6: Install Refrigeration. Heat Recovery $470,300 $8,900 ($1,502,000) ($1,022,800) 3.2
Medium Priority
EEM-7: Replace Zamboni $162,000 ($17,000) ($339,500) ($194,500) 2.2
EEM-8: Optimize HRVs $108,300 $0 ($189,500) ($81,200) 1.7
EEM-9: Dehumidify Using Recovered Heat $337,500 ($3,400) ($418,900) ($84,800) 1.3
EEM-10: Upgrade Motors $6,600 $0 ($8,000) ($1,400) 1.2
Totals* $1,087,800 ($12,400) ($2,556,100) ($1,480,700) 2.4
*The analysis is based on each EEM being independent of the others. While it is likely that some
EEMs are interrelated, an isolated analysis is used to demonstrate the economics because the audit
team is not able to predict which EEMs an Owner may choose to implement. If several EEMs are
implemented, the resulting energy savings is likely to differ from the sum of each EEM projection.
Summary
The energy audit revealed numerous opportunities for improving the energy performance of the
building. We recommend 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.
Treadwell Ice Arena 5 Energy Audit (December 2011)
Section 2
Introduction
This report presents the findings of an energy audit of the Treadwell Arena located in Douglas,
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 Treadwell Arena is a 36,158 square foot building that contains offices, commons spaces, locker
rooms, restrooms, storage, a mezzanine, an ice skating rink and bleachers, and mechanical support
spaces. The facility is operated by 12 staff and open from August – April. It is shut down from May –
July. It is occupied in the following manner:
Arena 6:00 am – Midnight (7 days per week) 20-85 people at any time
Snack Bar Operated approximately 20 times/year
Building History
2003 – Original Construction
2005 – Locker Room Addition
2010 – Light circuiting and switching modifications
Treadwell Ice Arena 6 Energy Audit (December 2011)
Energy Consumption
The building energy sources include an electric service and a fuel oil tank. Fuel oil is the primary
source for the majority of the heating loads and domestic hot water. Electricity is used for additional
domestic hot water and for the ice rink chiller system. Propane is used for the dehumidifier and the
Zamboni. The following table shows annual energy use and cost.
Annual Energy Consumption and Cost
Source Consumption Cost Energy, MMBtu
Electricity 695,570 kWh $65,300 2,400 43%
Fuel Oil 15,921 Gallons $56,000 2,200 39%
Propane 10,924 Gallons $25,200 1,000 18%
Totals $146,500 5,600 100%
Electricity
This chart shows electrical energy use
from 2007 to 2010. The effective cost—
energy costs plus demand charges—is
9.4¢ per kWh.
Fuel Oil and Propane
The building uses heating oil to heat the
lockers, office, and adjacent spaces.
Propane is used to dehumidify the ice rink
and operate the Zamboni. The following
chart shows the fuel oil and propane
energy use from 2007 to 2010. The chart
compares annual use with the heating
degree days which is a measurement of
the demand for energy to heat a building.
A year with a higher number of degree
days reflects colder outside temperatures
and a higher heating requirement.
Cost of Heat Comparison
The following 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%,
propane efficiency of 90%, and electric boiler
conversion efficiency of 95%. Electric heat is currently
less expensive than fuel oil heat.
Treadwell Ice Arena 7 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 are 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 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: De-Lamp Soft Drink Coolers
Purpose: The lamps for the soft drink coolers in the commons area run continuously and are not
necessary. Energy will be saved if the lamps are removed.
Scope: Remove lamps from the soft drink coolers in the commons area.
Treadwell Ice Arena 8 Energy Audit (December 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: Install Heating Pipe Insulation
Purpose: There are sections of uninsulated heating piping in the building. Energy will be saved if
these sections of piping are optimally insulated.
Scope: Install pipe insulation on uninsulated heating piping.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($650) ($650) $200 $0 ($18,300) ($18,100) 91.5
EEM-4: Replace Lavatory Aerators and Showerheads
Purpose: Energy and water will be saved by replacing the lavatory aerators and showers 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 ($2,640) ($2,640) $1,100 $0 ($66,900) ($65,800) 60.8
EEM-5: Install Sliding Doors in Skate Rental Pass-through Room
Purpose: The skate rental shop is a heated space that is always open to the skating arena space by a
6’x4’ opening. The reception office has a similar opening to the arena; however, a sliding
plexiglass window system was installed to help preserve heat. Energy will be saved if a
similar sliding window system is installed in the opening to the skate rental shop.
Scope: Install a sliding plexiglass window system in the 6’x4’ opening of the skate rental shop
space.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($50) ($460) ($510) $1,800 ($900) ($13,000) ($12,100) 7.7
Treadwell Ice Arena 9 Energy Audit (December 2011)
EEM-6: Install Refrigeration Heat Recovery
Purpose: The ice rink refrigeration system generates a large amount of heat, most of which is
discharged outside of the building. Energy will be saved by recovering the heat and using
it to heat rooms, ventilation air, and domestic water. This EEM is intended as the first
phase of a refrigeration heat recovery project, and would leave the propane dehumidifiers
in place. Heat recovery is a common feature of ice arenas and is supported by the
refrigeration manufacturer.
Scope: Retro-fit the rink refrigeration system with an “Eco-Chill” heat recovery system provided
by CIMCO, the original rink system manufacturer. The system will include a heat
exchanger to move heat from the hot refrigerant gas to a low temperature heating water
system, and a water storage tank for use during the off cycles of the refrigeration system.
Convert all heating systems in the building to use low temperature heating water. Install
additional domestic water heaters to provide adequate capacity with the low temperature
water.
CIMCO representatives would not respond to repeated requests for design and cost
information related to their products, and these are very specialized systems that are not
widely available. If the CBJ shows significant interest in this EEM, the manufacturer’s
costs should be gathered to verify the cost estimate.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$520 ($52,660) ($52,140) $470,300 $8,900 ($1,502,000) ($1,022,800) 3.2
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-7: Replace Zamboni
Purpose: The exhaust air from the propane-powered Zamboni significantly increases the humidity,
CO, and CO2 levels of the arena. Not only does this reduce the air quality in the building
for the occupants, it is the catalyst for the cycle of conflicting energy demands. Propane
is consumed to remove water vapor released by the Zamboni exhaust and remove water
vapor from the ventilation air that is needed to remove Zamboni pollutants. Energy to
operate the arena will be saved if the propane Zamboni is replaced with an electric model.
In addition to reducing arena energy requirements, the electric model ($0.25 per use) has
lower energy costs than the propane model ($1.11 per use).
Scope: Replace the propane powered Zamboni with an electric powered Zamboni.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($1,000) ($11,700) ($12,700) $162,000 ($17,000) ($339,500) ($194,500) 2.2
Treadwell Ice Arena 10 Energy Audit (December 2011)
EEM-8: Optimize Heat Recovery Ventilators
Purpose: The heat recovery ventilators (HRVs) for the locker rooms dehumidify and ventilate with
100% outside air. The lockers are used sporadically and seldom at full capacity. Energy
will be saved if the capacity of the HRVs is modulated to maintain adequate CO2 and
humidity levels.
The defrost controls for the HRVs appear to not be optimized. Optimization will increase
the heat recovery potential of the units.
The thermostats in the locker rooms served by AHU-3 are located adjacent to the door.
When the door opens, the cold rink air flows into the room, causing the thermostat to
sense a colder room. Energy will be saved if the thermostats are relocated to an interior
wall away from the door.
Scope: Perform the following modifications to the HRVs:
- Install VFDs on the HRV supply and return fans and controls to modulate air flow to
maintain adequate CO2 and humidity levels.
- Optimize the defrost controls to increase the heat recovery potential of the units.
- Relocate the HRV-3 thermostats to a wall within the locker room.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($6,740) ($6,740) $108,300 $0 ($189,500) ($81,200) 1.7
EEM-9: Dehumidify Using Recovered Heat
Purpose: The ice rink refrigeration system generates a large amount of heat, most of which is
discharged outside of the building. Energy will be saved by using the heat to provide de-
humidification. This EEM is intended as a second phase of the refrigeration heat recovery
project (EEM-6).
It is also possible to consider heating the rink with refrigeration air. This can be
accomplished by adding heat at the dehumidifier or by using the locker HRVs to supply
heated ventilation air to the arena and then transferring the air into the locker rooms to
makeup the exhaust. This possibility will require a through design effort as part of the
dehumidifier replacement design to determine if it is feasible.
Scope: Replace the existing propane-fired desiccant dehumidifiers with Munters Corporation
“Free-Dry” dehumidifiers, or similar. These units are specifically designed to operate
using low temperature heating water, and can provide tempered ventilation air to the rink
areas.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($200) ($14,780) ($14,980) $337,500 ($3,400) ($418,900) ($84,800) 1.3
Treadwell Ice Arena 11 Energy Audit (December 2011)
EEM-10: Upgrade Motors to Premium Efficiency
Purpose: The equipment inspection identified nine motors that could be upgraded with premium
efficiency models to save energy. They are:
- DH-1 5 HP from 87.5% efficiency to 91.0% efficiency
- Brine Pump 1 3 HP from 86.5% efficiency to 89.5% efficiency
- Brine Pump 2 3 HP from 86.5% efficiency to 89.5% efficiency
- Cold Brine Pump 20 HP from 91.0% efficiency to 93.0% efficiency
Scope: Replace identified motors with premium efficiency motors.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($410) ($410) $6,600 $0 ($8,000) ($1,400) 1.2
LOW PRIORITY
Low priority EEMs do not offer a life cycle energy savings and are not recommended.
EEM-11: Boiler Room Heat Recovery
Purpose: Heat loss from the boiler and hydronic heating system causes the boiler room temperature
to be 80-90°F. Energy will be saved if the heat in the boiler room is recovered and
transferred to the heated areas of the building.
Scope: Install a heat recovery unit in the boiler room space and transfer the heat to heated spaces
within the building. An analysis of this EEM is not provided because a refrigeration heat
recovery system, coupled with disabling the boiler when that system can meet the heating
load, will significantly reduce the heat gain in the boiler room. If refrigeration heat
recovery is not pursued, this EEM should be considered.
Treadwell Ice Arena 12 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 Section 3, Energy Efficiency Measures.
Building Envelope
R-value
Component Description (inside to outside) Existing Optimal
Exterior Walls R-19 batt insulation w/ metal siding R-20 R-26
Interior Walls 3/8” ply, 2”x4” wood stud, R-11 batt insulation 3/8” ply R-12 R-26
Arena Ceiling R-30 batt, ½” thermal block, metal roof R-30 R-46
Interior Ceilings 2” x 10” joists, R-20 R-46
Floor Slab 7” Concrete slab-on-grade w/ 4” foam insulation R-10 R-10
Foundation 8” concrete w/out insulation board R-5 R-20
Windows Vinyl double pane windows R-1.5 R-5
Doors Steel doors w/ non-thermally broken frames R-1.5 R-5
Heating System
The building is heated by one fuel oil boiler that provide heat to three heat recovery unit systems, unit
heaters, 5 indirect hot water heaters, and perimeter hydronic systems. The heating system has the
following pumps:
P-1 is a boiler circulation pump
P-2 is a boiler bypass pump
HWRP is a domestic hot water recirculation pump
Treadwell Ice Arena 13 Energy Audit (December 2011)
Ventilation Systems
Area Fan System Description
Main Entry Rooms HRV-1 2,090 cfm 2 HP air to air heat exchanger
Lockers/Showers 1-4 HRV-2 2,720 cfm 3 HP air to air heat exchanger
Locker Rooms 5 & 6 HRV-3 2,330 cfm 2 HP air to air heat exchanger
Arena Dehumidifier DH-1 253 MBTU dehumidifier
Arena Dehumidifier DH-2 235 MBTU dehumidifier
Ice Rink EF-1 6,000 cfm 1 ½ HP wall mounted propeller fan
Ice Rink EF-2 6,000 cfm 1 ½ HP wall mounted propeller fan
Refrigeration EF-3 250 cfm 1/20 HP centrifugal sidewall exhaust fan
Refrigeration EF-4 3,000 cfm ¾ HP wall mounted propeller fan
Domestic Hot Water System
The domestic hot water system consists of 5 indirect hot water heaters and 2 electric water heaters.
All 5 indirect hot water heaters are Amtrol 120 gallon units and designated as HWM-1 thru HWM-5.
HWM -1 and HWM-2 serve the Zamboni hot water supply, HWM-3 & HWM-4 serve locker rooms 1
thru 4, and HWM-5 serves locker rooms 5 & 6.
There is a 6-gallon electric direct hot water heater in the concessions space to deliver water heated to
120°F to the kitchen for code compliance, and there is a 50-gallon electric direct hot water heater in
the locker room mechanical mezzanine that supplies the official’s locker room domestic hot water
demand.
Cooling Systems
The ice rink is maintained by a 70-ton CIMCO chilling unit that rejects the heat to a rooftop mounted
condenser unit. As mentioned, there is no recovery of the rejected heat.
Automatic Control System
The building systems are controlled by a DDC system. The dehumidifiers and ice refrigeration system
are controlled from a local control panel.
Lighting
Interior lighting primarily consists of T8 fluorescent fixtures throughout the spaces and 1,000-watt
metal halide pendant fixtures above the arena. The pendant fixtures are made with a special glass due
to the potential for impact by hockey pucks. Exterior lighting primarily consists of compact
fluorescent and metal halide lighting.
Electric Equipment
Additional kitchen equipment for the support of concessions operations is located in the concessions
room.
Treadwell Ice Arena 14 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, and 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.
Treadwell Ice Arena 15 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 $3.80 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.
Propane
Propane currently costs $3.49 per gallon. The analysis is based on 6% inflation – propane prices are
fairly closely tied to that of fuel oil but with less volatility.
Treadwell Ice Arena 16 Energy Audit (December 2011)
Electricity
Electricity is supplied by Alaska Electric Light & Power Company (AEL&P). The building is billed
for electricity under AEL&P’s Rate 24. This rate charges for both electrical consumption (kWh) and
peak electric demand (kW). Electrical consumption is the amount of energy consumed and electric
demand is the rate of consumption. AEL&P determines the electric demand by averaging demand
over a continuously sliding fifteen minute window. The highest fifteen minute average during the
billing period determines the peak demand. The following table lists the electric charges, which
includes a 24% rate hike that was recently approved:
AEL&P Small Government Rate with Demand
Charge 1 On-peak (Nov-May) Off-peak (June-Oct)
Energy Charge per kWh 6.11¢ 5.92¢
Demand Charge per kW $14.30 $9.11
Service Charge per month $99.24 $99.24
Over recent history, electricity inflation has been less than 1% per year, which has lagged general
inflation. An exception is the recent 24% rate hike that was primarily due to construction of additional
hydroelectric generation at Lake Dorothy. This project affords the community a surplus of power
which should bring electric inflation back to the historic rate of 1% per year. Load growth from
electric heat conversions is likely to increase generating and distribution costs, especially if diesel
supplementation is needed. Combining these two factors contribute to an assumed electricity inflation
rate of 3%.
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 $0.094/kWh
General Inflation Rate 2% Electricity Inflation 3%
Fuel Oil Cost (2012) $3.80/gal Fuel Oil Inflation 6%
Propane (2012) $3.49/gal Propane Inflation 6%
Treadwell Ice Arena 17 Energy Audit (December 2011)
Appendix A
Energy and Life Cycle Cost Analysis
Treadwell Ice Arena 18 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
Treadwell Ice Arena
Basis
Economic
Study Period (years) 25 Nominal Discount Rate 5%General Inflation 2%
Energy
2011 $/gal Fuel Inflation 2012 $/gal
Fuel Oil $3.52 6% $3.73
Electricity $/kWh (2011)$/kW (2011)Inflation $/kWh (2012)$/kW (2012)
w/ Demand Charges $0.060 $12.14 3% $0.062 $12.50
w/o Demand Charges $0.094 -3% $0.097 -
EEM-3: Install Heating Pipe Insulation
Energy Analysis
Service Size Length Bare BTUH Insul BTUH Factor kBtu η boiler Gallons
Heating 0.50 3 61 10 100% -1,340 72%-13
Heating 0.75 20 74 11 100% -11,038 72%-111
Heating 2.00 4 154 15 100% -4,871 72%-49
-173
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Pipe Insulation 1/2"0 3 lnft $5 $15
3/4"0 20 lnft $5 $100
1"0 4 lnft $6 $24
Estimating contingency 0 15%$21
Overhead & profit 0 30%$48
Design fees 0 10%$21
Project management 0 8%$18
Energy Costs
Fuel Oil 1 - 25 -173 gal $3.73 ($18,293)
Net Present Worth ($18,000)
EEM-4: Replace Aerators and Showerheads
Energy Analysis
η boiler 68%
Fixture Existing Proposed Uses/day Days Water,Gals % HW kBTU Gallons
Showerhead 20.0 10.0 25 270 -67,500 80% -36,029 -383
Lavatories 0.3 0.2 300 270 -14,580 80% -7,782 -83
-82,080 -465
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace lavatory aerators 0 12 ea $35 $420
Replace showerhead 0 18 ea $35 $630
Energy Costs
Water 1 - 25 -82 kgals $10.960 ($17,684)
Fuel Oil 1 - 25 -465 gal $3.73 ($49,197)
Net Present Worth ($65,800)
Gallons per Use
Treadwell Ice Arena 19 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
Treadwell Ice Arena
EEM-5: Install Door in Skate Rental Pass-through
Energy Analysis
CFM Tave Trm Hours MBH kBtu η boiler Gallons
-150 38 70 2,190 -5 -11,563 68% -123
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install plexiglass door 0 1 LS $1,000 $1,000
Estimating contingency 0 15%$150
Overhead & profit 0 30%$345
Design fees 0 10%$150
Project management 0 8%$132
Annual Costs
Exhaust fan maintenance 1 - 25 -1 LS $50.00 ($851)
1 - 25 $60.00 $0
1 - 25 $50.00 $0
Energy Costs
Fuel Oil 1 - 25 -123 gal $3.73 ($12,985)
Net Present Worth ($12,100)
Treadwell Ice Arena 20 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
Treadwell Ice Arena
EEM-6: Install Refrigeration Heat Recovery
Energy Analysis
Refrigeration Heat Recovery
Peak MBH Average Ave MBH COP Rejected MBH % Used Ave, MBH Boiler MBH % Load
840 60% 504 3.0 672 11% 598 764 88%
Locker Room Heating Load
HRV CFM ΔT η, HRV Peak MBH
HRV-1 2,090 74 70% 51
HRV-2 2,360 74 70% 58
HRV-3 2,720 74 70% 66 Design MBH
175 175
Domestic Hot Water
HWTs GPH ΔT MBH
5 266 80 887
Showers GPM ΔT MBH 240
3 2.0 80 240 415
Fuel Oil
Fuel Oil, gal % Supplement Savings, gal
16,000 -90% -14,400
Pumping Energy
Mode GPM Head η pump BHP η motor kW Hours kWh
New P-3 52 65 55% 2.1 86.5% 1.8 7,200 12,909
1.8 12,909
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Heat Recovery System
Heat recovery heat exchanger 0 1 LS $30,000 $30,000
4,000 gallon storage tank 0 1 LS $45,000 $45,000
Hydronic heating piping 0 1 LS $50,000 $50,000
Controls 0 1 LS $15,000 $15,000
Convert heating units to low temperature
Primary pump and piping 0 1 LS $28,000 $28,000
Additional hot water makers 0 5 LS $10,000 $50,000
Replace unit heaters 0 5 LS $1,500 $7,500
Replace cabinet unit heaters 0 4 LS $2,200 $8,800
Replace finned tube heaters 0 1 LS $1,500 $1,500
Add HRV heating coils 0 3 LS $8,000 $24,000
Test and balance, commissioning 0 1 LS $5,000 $5,000
Estimating contingency 0 15% $39,720
Overhead & profit 0 30% $91,356
Design fees 0 10% $39,588
Project management 0 8% $34,837
Annual Costs
Heat exchanger maintenance 1 - 25 1 ea $120.00 $2,043
Pump maintenance 1 - 25 2 ea $200.00 $6,811
Energy Costs
Electric Energy 1 - 25 12,909 kWh $0.062 $15,683
Electric Demand 1 - 25 22 kW $12.50 $5,289
Fuel Oil 1 - 25 -14,400 gal $3.73 ($1,522,932)
Net Present Worth ($1,022,800)
Treadwell Ice Arena 21 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
Treadwell Ice Arena
EEM-7: Replace Zamboni
Energy Analysis
Zamboni
Propane
Uses/day Days Gal/Use Propane, gal/yr
-14 270 0.48 -1,800
Electricity
Uses/day Days kWh/use kWh
14 270 2.5 9,450
Dehumidification
Btu/hr Water lb/hr Btu/lb water lb/gal Btu/gal BTU/gal Propane gal/gal h2o
250,000 60 4,167 8.34 34,750 91,000 0.38
Propane water/prop gal h2o propane, gal
Zamboni -1,800 0.8 -1,440 -550
Humidity
Zamboni gal/day lb / gal ft3 / lb CO2 / Prop
Ventilation Air -7.0 4.2 8.3 3
OSA ave Rink
Δ ppm hr/day cfm grains/lba grains/lb ft3/lb grains/lb gal h2o gal/pro
800 21 -726 43 22 12.5 7,000 -7,110 -2,715
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Electric Zamboni 0 1 LS $200,000 $200,000
Sell propane Zamboni 0 1 LS ($50,000) ($50,000)
Project management 0 8% $12,000
Annual Costs
Propane Zamboni maintenance 1 - 25 -1 ea $2,500.00 ($42,568)
Electric Zamboni maintenace 1 - 25 1 ea $1,500.00 $25,541
Energy Costs
Electric Energy (Effective Cost)1 - 25 9,450 kWh $0.097 $17,986
Propane 1 - 25 -5,065 gal $2.49 ($357,473)
Net Present Worth ($194,500)
Dehumidification Propane
Propane
Air Quality
Treadwell Ice Arena 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
Treadwell Ice Arena
EEM-8: Optimize HRVs
Energy Analysis
HRV Heating Energy
Unit CFM,ex η exist CFM,proposed η proposed ΔT Heat, kBtu η boiler Gallons
HRV-1 2,090 60% 1,568 62% 30 -44,154 72%-443
HRV-2 2,720 60% 2,040 62% 30 -57,464 72%-576
HRV-3 2,330 60% 1,748 62% 30 -49,225 72%-494
7,140 5,355 -1,513
Locker Heating Energy
Unit CFM,proposed η proposed ΔT Savings, kBtu η boiler Gallons
HRV-3 1,748 62%-6 -24,398 72% -245
Fan Energy
Unit ΔCFM ΔP η, fan # Fans Hours kW kWh
HRV-1 -523 0.50 40%2 5,670 -0.2 -869
HRV-2 -680 0.50 40%2 5,670 -0.2 -1,131
HRV-3 -583 0.50 40%2 5,670 -0.2 -969
-1,785 -2,968
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install VFD 0 6 ea $5,000 $30,000
Relocate thermostats 0 2 LS $500 $1,000
Controls 0 3 ea $10,000 $30,000
Estimating contingency 0 15%$9,150
Overhead & profit 0 30% $21,045
Design fees 0 10%$9,120
Project management 0 8%$8,025
Energy Costs
Electric Energy 1 - 25 -2,968 kWh $0.062 ($3,606)
Fuel Oil 1 - 25 -1,757 gal $3.73 ($185,854)
Net Present Worth ($81,100)
EEM-9: Dehumidify Using Recovered Heat
Energy Analysis
Propane
Exist, gal Zamboni EEM Dehumid, gal
11,000 -5,065 -5,935
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace dehumidifier 0 1 LS $190,000 $190,000
Estimating contingency 0 15% $28,500
Overhead & profit 0 30% $65,550
Design fees 0 10% $28,405
Project management 0 8% $24,996
Annual Costs
Propane dehumidifer maintenance 1 - 25 -1 ea $400.00 ($6,811)
Free-Dry deumidifier maintenance 1 - 25 1 ea $200.00 $3,405
Energy Costs
Propane 1 - 25 -5,935 gal $2.49 ($418,884)
Net Present Worth ($84,800)
Treadwell Ice Arena 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
Treadwell Ice Arena
EEM-10: Upgrade Motors
Energy Analysis
Equip Number HP ηold ηnew kW Hours kWh
Brine Pump-1/2 2 3 86.5% 89.5% -0.13 5,256 -706
DH-1 1 5 87.5% 89.5% -0.07 2,891 -216
Cold Brine 1 20 88.5% 93.0% -0.67 5,256 -3,529
-0.9 -4,450
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs HP
Replace motor 3 0 2 LS 1,080 $2,160
Replace motor 5 0 1 LS 1,290 $1,290
Replace motor 20 0 1 LS 3,160 $3,160
Energy Costs
Electric Energy 1 - 25 -4,450 kWh $0.062 ($5,406)
Electric Demand 1 - 25 -11 kW $12.50 ($2,597)
Net Present Worth ($1,400)
Treadwell Ice Arena 24 Energy Audit (December 2011)
Appendix B
Energy and Utility Data
Treadwell Ice Arena 25 Energy Audit (December 2011)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Treadwell Ice Arena
ELECTRIC RATE
Electricity ($ / kWh )0.0611 0.0592
Demand ( $ / kW )14.30 9.11
Customer Charge ( $ / mo )99.24 99.24
Sales Tax ( % )0.0% 0.0%
ELECTRICAL CONSUMPTION AND DEMAND
kWh kW kWh kW kWh kW kWh kW
Jan 66,320 165 69,760 182 62,800 182 68,960 181 66,960
Feb 76,640 163 79,720 180 74,800 171 76,960 182 77,030
Mar 70,800 169 77,160 178 74,320 182 79,360 181 75,410
Apr 73,800 163 71,040 179 73,200 182 74,280 182 73,080
May 25,400 164 16,840 162 19,960 178 14,960 36 19,290
Jun 11,480 40 8,040 28 9,160 40 7,080 35 8,940
Jul 10,440 41 8,240 36 8,640 40 8,600 33 8,980
Aug 66,320 168 57,440 169 47,720 181 45,400 163 54,220
Sep 79,160 162 63,200 162 70,680 167 64,200 161 69,310
Oct 79,480 161 80,600 178 72,880 177 81,840 169 78,700
Nov 92,520 166 79,240 181 84,600 182 90,480 184 86,710
Dec 79,600 181 78,480 182 76,880 182 72,800 182 76,940
Total 731,960 689,760 675,640 684,920 695,570
Average 60,997 145 57,480 151 56,303 156 57,077 141 57,964
Load Factor 57.5%52.0%49.6%55.5%148
ELECTRIC BILLING DETAILS
Month Energy Demand Cust & Tax Total Energy Demand Cust & Tax Total % Change
Jan 3,837 2,603 99 6,539 4,213 2,591 99 6,904 5.6%
Feb 4,570 2,448 99 7,118 4,702 2,608 99 7,410 4.1%
Mar 4,541 2,608 99 7,249 4,849 2,588 99 7,536 4.0%
Apr 4,473 2,608 99 7,180 4,539 2,608 99 7,246 0.9%
May 1,220 2,545 99 3,864 914 515 99 1,528 -60.5%
Jun 560 368 99 1,027 433 319 99 851 -17.2%
Jul 528 368 99 995 525 299 99 924 -7.2%
Aug 2,916 1,651 99 4,666 2,774 1,487 99 4,360 -6.6%
Sep 4,319 1,523 99 5,941 3,923 1,469 99 5,490 -7.6%
Oct 4,453 1,614 99 6,167 5,000 1,538 99 6,637 7.6%
Nov 5,169 2,603 99 7,871 5,528 2,631 99 8,259 4.9%
Dec 4,697 2,608 99 7,405 4,448 2,603 99 7,150 -3.4%
Total $ 41,282 $ 23,548 $ 1,191 $ 66,021 $ 41,849 $ 21,255 $ 1,191 $ 64,295 -2.6%
Average $ 3,440 $ 1,962 $ 99 $ 5,502 $ 3,487 $ 1,771 $ 99 $ 5,358 -2.6%
Cost ($/kWh)$0.098 65% 33% 2% $0.094 -3.9%
Electrical costs are based on the current electric rates.
2009 2010
2010
AEL&P Electric Rate 24 On-Peak
Nov-May
Off-peak
Jun-Oct
Month 2007 2008 2009 Average
Treadwell Ice Arena 26 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
Treadwell Ice Arena
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
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
50
100
150
200
250
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Demand (kW)Month of the Year
Electric Demand History
2007
2008
2009
2010
Treadwell Ice Arena 27 Energy Audit (December 2011)
Alaska Energy Engineering LLC Electric Cost
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Treadwell Ice Arena 2010
$ 0
$ 1,000
$ 2,000
$ 3,000
$ 4,000
$ 5,000
$ 6,000
$ 7,000
$ 8,000
$ 9,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecElectric Cost (USD)Month of the Year
Electric Cost Breakdown
2010
Electric Use (kWh) Costs
Electric Demand (kW) Costs
Customer Charge and Taxes
0
20
40
60
80
100
120
140
160
180
200
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Electric Demand (kW)Electric Use (kWh)Month of the Year
Electric Use and Demand Comparison
2010
Electric Use
Electric Demand
Treadwell Ice Arena 28 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
Treadwell Ice Arena
Year 2,007 2,008 2,009 2,010 Average
16,170 16,981 16,107 14,424 15,921
9,124 9,124 9,124 9,124 9,124
1,800 1,800 1,800 1,800 1,800
9,282 9,093 9,284 9,013 26,845
Degree Days
Fuel Oil - Heat
Propane - Dehumidification
Propane - Zamboni
0
2,000
4,000
6,000
8,000
10,000
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
2007 2008 2009 2010 Degree DayGallonsYear
Annual Fuel Oil and Propane Use
Fuel Oil ‐ Heat Propane ‐ Dehumidification
Propane ‐ Zamboni Degree Days
Treadwell Ice Arena 29 Energy Audit (December 2011)
Alaska Energy Engineering LLC Annual Water Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Treadwell Ice Arena
Year Water
2,007 552,000
2,008 564,000
2,009 516,000
2,010 480,000
350,000
400,000
450,000
500,000
550,000
600,000
2007 2008 2009 2010Gallons of WaterYear
Annual Water Use
Treadwell Ice Arena 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
Annual Energy Consumption and Cost
Energy Cost $/MMBtu Area ECI EUI
Fuel Oil $3.52 $36.31 36,158 $4.05 155
Electricity $0.094 $28.96
Propane $2.31 $29.02
Source Cost
Electricity 695,570 kWh $65,300 2,400 43%
Fuel Oil 15,921 Gallons $56,000 2,200 39%
Propane 10,924 Gallons $25,200 1,000 18%
Totals $146,500 5,600 100%
Annual Energy Consumption and Cost
Consumption Energy, MMBtu
$0.00
$5.00
$10.00
$15.00
$20.00
$25.00
$30.00
$35.00
$40.00
Fuel Oil Electricity PropaneCost $ / MMBtuCost of Heat Comparison
Treadwell Ice Arena 31 Energy Audit (December 2011)
Appendix C
Equipment Data
Treadwell Ice Arena 32 Energy Audit (December 2011)
MotorHP / Volts / RPM / EfficHRV 1 Mezzanine Heat RecoveryHeatex E-50002090 cfm 2 HP/ 1740 RPM/ 480 V/ 87.5%Mezzanine Exhaust2 HP/ 480 V/ 1740 RPM/87.5%HRV 2 Mezzanine Heat RecoveryHeatex E-50002720 cfm 3 HP/ 480 V/ 1760 RPM/ 89.5%Mezzanine Exhaust3 HP/ 480 V/ 1760 RPM/ 89.5%DH 1 Mezzanine DehumidifierCimco DH-130-300 253 MBTU 5 HP/ 480 V/ 3490 RPM/ 87.5%Mezzanine De-Activation Blower6.5 HP/ 480 V/ 3486 RPM/ 88%LMA Mezzanine TransformerSquare D 30T3H30 KVANon TP rated EHWM 3 CustodialLockers 1-4/ Bathroom HW Amtrol WH1202CDW 120 GallonIndirect HW heaterHWM 4 CustodialLockers 1-4/ Bathroom HW Amtrol WH1202CDW 120 GallonIndirect HW heaterHWRP 1 CustodialDomestic HW Return Pump TACO DO3-B41/40 HP/115V/ 45 AMP/ 3250 RPM Runs 24/7WH 1 Concession Direct HW Heater Not Available6 Gallon 115 V/ 1500 Watts120° waterHWM 5Locker Rm MechanicalLocker Room 5/6 Amtrol WH1202CDW 120 GallonIndirect HW heaterHRV 3Locker Rm MechanicalLockers 5/6 Supply Innovent2 HP/ 480 V/ 1750 RPM/ 87.5%Locker Rm MechanicalLockers 5/6 Exhaust2 HP/ 480 V/ 1750 RPM/ 87.5%DH 2Locker Rm MechanicalMain Dehumidifier Blower Cameo235 MBTU 5 HP/ 480 V/ 3490 RPM/ 87.5%Locker Rm MechanicalDe-Activation Blower2 HP/ 480 V/ 3490 RPM/ 85%WH 2Locker Rm MechanicalOfficials Locker HW BradfordM250T60S-INCWW50 Gallon 208 V/ 3500 W upper/ lower Tied in to HW loopB 1 Boiler Room BoilerWeil McLain780753 MGHP 2 Boiler Room Boiler Circulation Pump TACO1/25 HP/ 115V/ 3250 RPMP 1 Boiler Room Boiler Circulation Pump Grundfos VPSEO-240F480 W/ 1700 WRunning high speedHWM 2 Boiler Room Zamboni HWAmtrol WH120ZCDW 120 GallonIndirect HW heaterTreadwell Ice Arena - Major Equipment InventoryCapacityNonesUnit IDLocation Function Make Model
Treadwell Ice Arena 33 Energy Audit (December 2011)
MotorHP / Volts / RPM / EfficTreadwell Ice Arena - Major Equipment InventoryCapacityNonesUnit IDLocation Function Make ModelHWM 1 Boiler Room Zamboni HWAmtrol WH120ZCDW 120 GallonIndirect HW heaterL1A Boiler Room TransformerSquare D 30 T3H30 KVANon TP ratedIcemaker Refrigeration Room IcemakerCIMCO 29504070 TRRefrigeration Room Warm Brine Pump 13 HP/ 480 V/1760 RPM/ 86.5%Refrigeration Room Warm Brine Pump 23 HP/ 480 V/1760 RPM/ 86.5%Refrigeration Room Cold Brine Pump20 HP/ 480 V/ 1760 RPM/ 91%Icemaker Refrigeration Room Compressor 170 HPRuns 75% timeRefrigeration Room Compressor 270 HPRuns 60-75% timeEF 1 Ice RinkExhaust FanGreenheck6000 CFM 1 1/2 HP/ 480 V/ 84%EF 2 Ice RinkExhaust FanGreenheck6000 CFM 1 1/2 HP/ 480 V/ 84%EF 3 Refrigeration Exhaust FanGreenheck250 CFM 1/20 HP/ 480 VEF 4 Refrigeration Exhaust FanGreenheck3000 CFM 3/4 HP/ 480 V/82%Zamboni Ice RinkIce ResurfacerZamboni 500
Treadwell Ice Arena 34 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
Treadwell Ice Arena 35 Energy Audit (December 2011)