HomeMy WebLinkAboutSEA-AEE-JNU Mendenhall Valley School 2012-EE
Mendenhall River School
Juneau School District
Funded by:
Final Report
February 2012
Prepared by:
Energy Audit
Alaska Energy Engineering LLC Addendum
25200 Amalga Harbor Road Tel/Fax: 907.789.1226 April 15, 2012
Juneau, Alaska 99801 jim@alaskaenergy.us
to: Energy Audit Recipient
subject: Flow Down Requirements
project: AHFC Energy Audits – Sealaska Region
The energy audits that we provided were funded the U.S. Department of Energy. We are required
to include with the audit the following Acknowledgement and Disclaimer. Please add this
Addendum to your final energy audit report.
Acknowledgment: "This material is based upon work supported by the Department of Energy
under Award Number DE-EE0000095
Disclaimer: "This report was prepared as an account of work sponsored by an agency of the
United States Government. Neither the United States Government nor any agency thereof,
nor any of their employees, makes any warranty, express or implied, or assumes any legal
liability or responsibility for the accuracy, completeness, or usefulness of any information,
apparatus, product, or process disclosed, or represents that its use would not infringe
privately owned rights. Reference herein to any specific commercial product, process, or
service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute
or imply its endorsement, recommendation, or favoring by the United States Government or
any agency thereof. The views and opinions of authors expressed herein do not necessarily
state or reflect those of the United States Government or any agency thereof.
Thank you.
by: Jim Rehfeldt, P.E.
Table of Contents
Section 1: Executive Summary 2
Section 2: Introduction 6
Section 3: Energy Efficiency Measures 8
Section 4: Description of Systems 14
Section 5: Methodology 17
Appendix A: Energy and Life Cycle Cost Analysis 20
Appendix B: Energy and Utility Data 28
Appendix C: Equipment Data 35
Appendix D: Abbreviations 39
Audit Team
The energy audit is performed by Alaska Energy Engineering LLC of Juneau, Alaska. The audit team
consists of:
Jim Rehfeldt, P.E., Energy Engineer
Jack Christiansen, Energy Consultant
Brad Campbell, Energy Auditor
Loras O’Toole P.E., Mechanical Engineer
Will Van Dyken P.E., Electrical Engineer
Curt Smit, P.E., Mechanical Engineer
Philip Iverson, Construction Estimator
Karla Hart, Technical Publications Specialist
Jill Carlile, Data Analyst
Grayson Carlile, Energy Modeler
Mendenhall River School 1 Energy Audit (February 2012)
Section 1
Executive Summary
An energy audit of the Mendenhall River Elementary School was performed by Alaska Energy
Engineering LLC. The investment grade audit was funded by Alaska Housing Finance Corporation
(AHFC) to identify opportunities to improve the energy performance of public buildings throughout
Alaska.
Mendenhall River Elementary School is a 58,669 square foot building that contains commons,
classrooms, offices, a music room, a gym, a kitchen and cafeteria, a library, storage, and mechanical
support spaces.
Building Assessment
The following summarizes our assessment of the building.
Envelope
The building envelope of Mendenhall River Elementary School appears to be providing good service
and is well maintained. The school is very simplistic in its design, which has added to its longevity.
However, the building is not completely without envelope issues. These include the following:
Roof Insulation: The roof was originally designed with only 5” of rigid insulation, providing an
R-20 assembly, way below the current R-56 standard. Although the opportunity presented itself
to increase the insulation when the roof was repaired in 1999, no additional insulation was added.
We recommend that additional roof insulation be installed when future roofing projects are
performed.
Roof Overhang: The classroom bay windows have very little roof overhang above them. As a
result, the window frames are exposed to more moisture than the remaining building windows.
The bay windows are in good condition; however, the bottom sill and trim pieces are difficult to
maintain due to a constant exposure to moisture.
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 System
The building has a fuel oil boiler and an electric boiler. Currently the fuel oil boiler is operating and
the electric boiler is shut down.
The hydronic heating system varies flow through the boilers. Modern designs typically use constant
flow through the boilers. The remainder of the fuel oil boiler heating system 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.
Mendenhall River School 2 Energy Audit (February 2012)
Ventilation Systems
The building has seven air handling unit systems and 23 individual exhaust fans.
The school utilizes a heat wheel to reclaim heat from exhaust air. The heat wheel efficiency is low;
more efficient models are now manufactured.
The outside air dampers on fans F-6 and F-7 are completely closed. As a result, these fan systems are
not adequately ventilating their respective classrooms, which are the end wings of the building. CO2
monitoring determined that the wings have CO2 levels of 1200-1500 ppm, much higher than the
desired level of 800 ppm. We recommend that the outside air dampers be repaired and operated
properly on these systems.
The number of exhaust fans in the building is excessive and most of them are manually controlled by
multiple staff members. As a result, they are often left on for extended periods when they are not
needed. While EF-1 and EF-2 are automatically controlled to operate when the building is occupied,
operation of EF-3 thru EF-22 can be improved. Suggested modifications include utilizing the heat
wheel for more of the toilet exhaust and recovering heat from server room exhaust. They are
discussed in Section 3, Energy Efficiency Measures.
Lighting
Interior lighting consists primarily of T12 fluorescent fixtures and metal halide lighting. Exterior
lighting consists primarily of high pressure sodium fixtures. No recommendations are made for the
conversion of interior lighting to more efficient fixtures because the heat generated by the current
lighting fixtures is less expensive than heat produced by the boiler system at current fuel and electric
rates.
Summary
The overall energy performance of Mendenhall River Elementary School at 58 kBtu/sqft is slightly
less than the 66 kBtu’s/sq ft average of all the Juneau buildings. Now that the audit team has nearly
completed reviews of most of the buildings under this program, we can look at a more useful metric
for measuring energy data in the Juneau School District – kBtu/student. This quantifies how much
energy is required per student educated at a particular building.
Riverbend Elementary School Constructed 1997 19,744 kBtu/student
JDHS High School Renovated 2002 17,340 kBtu/student
Thunder Mountain High School Constructed 2006 16,340 kBtu/student
Dzantiki Heeni Middle School Constructed 1992 12,480 kBtu/student
Mendenhall River Elementary School Constructed 1984 7,913 kBtu/student
This data shows that newer buildings such as JDHS, Riverbend Elementary, and Thunder Mountain
use over twice as much energy/student as Mendenhall River Elementary School. The audit team has
not quantified the reason for this, but believes it is tied to tightness of construction, sizing of systems,
and systemic inefficiencies that result from system sizing criteria that penalizes energy efficiency.
Mendenhall River School 3 Energy Audit (February 2012)
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: Energy Star Appliances
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: Reduce Arctic Entries Temperatures $100 $0 ($16,900) ($16,800) 169.0
EEM-4: Operate Electric Hot Water Heater $200 $0 ($27,700) ($27,500) 138.5
EEM-5: Replace Lavatory Aerators $600 $0 ($29,600) ($29,000) 49.3
EEM-6: Operate Electric Boiler $5,000 ($4,100) ($237,000) ($236,100) 48.2
EEM-7: Install Program Clocks on Exhaust Fans $1,500 $0 ($54,500) ($53,000) 36.3
EEM-8: Operate Boiler on Low Fire $500 $1,000 ($16,400) ($14,900) 30.8
EEM-9: Install Exhaust Fan Timer Switches $1,500 $0 ($35,000) ($33,500) 23.3
EEM-10: Install Pipe Insulation $2,200 $0 ($22,300) ($20,100) 10.1
Medium Priority
EEM-11: Optimize Ventilation Systems $83,500 $0 ($206,100) ($122,600) 2.5
EEM-12: Boiler/Electric Rm Heat Recovery $45,800 $2,000 ($101,100) ($53,300) 2.2
EEM-13: Upgrade Transformers $36,800 $0 ($45,400) ($8,600) 1.2
Totals* $177,700 ($1,100) ($792,000) ($615,400) 4.5
*The analysis is based on each EEM being independent of the others. While it is likely that some
EEMs are interrelated, an isolated analysis is used to demonstrate the economics because the audit
team is not able to predict which EEMs an Owner may choose to implement. If several EEMs are
implemented, the resulting energy savings is likely to differ from the sum of each EEM projection.
Mendenhall River School 4 Energy Audit (February 2012)
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.
Mendenhall River School 5 Energy Audit (February 2012)
Section 2
Introduction
This report presents the findings of an energy audit of the Riverbend Elementary School located in
Juneau, 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
Mendenhall River Elementary School is a 58,669 square foot building that contains commons,
classrooms, offices, a music room, a gym, a kitchen and cafeteria, a library, storage, and mechanical
support spaces. The elementary school is operated by 50 staff and attended by 430 students. The
facility is occupied in the following manner:
Teachers 7:30 am – 3:00pm (M-F)
Students 8:00 am – 2:30 pm (M-F)
Gym 8:00 am – 11:00 pm 7 days/week as needed for community use
Building History
1982 – Original Construction
1999 – Roof Replacement
Mendenhall River School 6 Energy Audit (February 2012)
Energy Consumption
The building energy sources include an electric service and a fuel oil tank. Fuel oil is used for the
majority of the heating loads and domestic hot water while electricity serves all other loads.
Electricity can be used for building heat if the electric boiler is returned to service. The following
table shows annual energy use and cost.
Annual Energy Consumption and Cost
Source Consumption Cost Energy, MMBtu
Electricity 407,378 kWh $46,600 1,400 41%
Fuel Oil 14,396 Gallons $50,700 2,000 59%
Totals $97,300 3,400 100%
Electricity
This chart shows electrical energy use
from 2008 to 2011, during which time the
electrical consumption has been steady.
The electric boiler was turned off in 2008
at the request of AEL&P following the
avalanche.
The effective cost—energy costs plus
demand charges—is 11.4¢ per kWh.
Fuel Oil
This chart shows heating energy use from
2008 to 2011. The chart compares annual
use with the heating degree days which is
a measurement of the annual heating
requirement. A year with a higher number
of degree days reflects colder outside
temperatures and a higher heating
requirement. It is not known why fuel oil
demand increased as much as it did in
2010.
Cost of Heat Comparison
This chart shows a comparison of the current cost of
fuel oil heat and electric heat. The comparison is based
on a fuel oil conversion efficiency of 70% and an
electric boiler conversion efficiency of 95%. Electric
heat is currently less expensive than fuel oil heat.
Mendenhall River School 7 Energy Audit (February 2012)
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: While the school exterior single-wide door weather stripping is in good shape, the double
doors do not seal well against the center mullions and are missing weather stripping in
places. Energy will be saved if the double doors are properly weather-stripped to reduce
infiltration.
Scope: Replace weather stripping on exterior double doors.
EEM-2: Energy Star Appliances
Purpose: Many of the appliances in the school are not Energy Star rated. Energy will be saved if
these units are replaced with Energy Star rated units at the end of their useful life.
Scope: Replace non-Energy Star rated appliances with Energy Star rated units at the end of their
useful life.
Mendenhall River School 8 Energy Audit (February 2012)
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: Reduce Artic Entries Temperatures
Purpose: The nine arctic entryways use a cabinet fan heater to heat and dry each entrance. The
thermostat to these units controls operation of the heater and a Low/Med/High selector
switch controls the fan speed. The thermostats were set at-or-above 65°F. Energy will be
saved if programmable thermostats are installed and the entryway thermostat setpoints
are lowered to 55°F in all nine arctic entryways.
Scope: Lower the entryway thermostat setpoints to 55°F in all nine arctic entryways.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($600) ($600) $100 $0 ($16,900) ($16,800) 169.0
EEM-4: Operate Electric Domestic Hot Water Heater
Purpose: The boiler room contains both an electric and an indirect domestic hot water heater of
similar size. Currently the school uses the indirect hot water heater during the school year
while the boiler system is operating. In the summer months when the boiler is turned off
the electric hot water heater is used. Energy will be saved if domestic hot water is heated
with lower cost electricity and a few of the stages are disabled to reduce demand charges.
Scope: Disable the fuel oil boiler and operate the electric hot water heater. Disable a few of the
stages to reduce demand charges.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,340) ($1,340) $200 $0 ($27,700) ($27,500) 138.5
EEM-5: Replace Lavatory Aerators
Purpose: Energy and water will be saved by replacing the lavatory aerators with low-flow models.
Scope: Replace lavatory aerators with water-conserving fixtures.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,510) ($1,510) $600 $0 ($29,600) ($29,000) 49.3
Mendenhall River School 9 Energy Audit (February 2012)
EEM-6: Operate Electric Boiler
Purpose: The 420 kW electric boiler is currently disabled. The boiler remains on AEL&P’s
interruptible electric heat rate which sells power at a 10 percent savings to fuel oil.
Energy costs will be reduced if the electric boiler is operated as the primary boiler to heat
the school building.
Scope: Operate the electric boiler as the primary boiler for the school and utilize the fuel oil
boiler to supplement the remaining heat load when necessary.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
($240) ($8,360) ($8,600) $5,000 ($4,100) ($237,000) ($236,100) 48.2
EEM-7: Install Program Clocks on Exhaust Fans
Purpose: Exhaust fans EF-7 in the janitor’s closet and EF-19 and EF-20 in the west central wing
are manually controlled by staff to run through the day and evening; however, they are
frequently left on continuously. Energy will be saved if program clocks are installed on
these fans so they only operate when necessary.
Scope: Install program clocks on the following exhaust fans:
- Janitors Closet Room J251 EF-7 400 cfm
- West Central Wing Restroom Room 202 EF-19 400 cfm
- West Central Wing Restroom Room 203 EF-20 400 cfm
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,920) ($1,920) $1,500 $0 ($54,500) ($53,000) 36.3
EEM-8: Operate Boiler on Low Fire
Purpose: The fuel oil boiler has a low fire setting. Energy will be saved if the boiler is kept on the
low fire setting when heating loads are moderate. When outside temperatures drop and
loads increase, switch to the high fire setting.
Scope: Operate the boiler on high fire during cold weather—roughly November to February—
and on low fire during other times when it can supply the heating load.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$60 ($580) ($520) $500 $1,000 ($16,400) ($14,900) 30.8
Mendenhall River School 10 Energy Audit (February 2012)
EEM-9: Install Exhaust Fan Timer Switches
Purpose: Many of the school’s exhaust fans are only used intermittently and controlled by manual
switches. They are reportedly often left on when no longer needed. Energy will be saved
if timers are installed so that the fans will shut themselves off.
Scope: Install timer switches on the following exhaust fans:
- Copy Room EF-6
- Kitchen Prep EF-8
- PE Storage EF-9
- Nurse’s RR EF-14
- Lounge EF-15
- Conference EF-16
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($1,240) ($1,240) $1,500 $0 ($35,000) ($33,500) 23.3
EEM-10: Install Pipe Insulation
Purpose: A significant amount of boiler and domestic hot water piping insulation is missing or was
never installed. Energy will be saved if these sections of piping are optimally insulated.
Scope: Install pipe insulation on the following:
- 15’ of 1-½” fan coil supply pipe in the gym fan room (ECW Room 455)
- 2’ of ¾” fan coil supply pipe in the gym fan room (ECW Room 455)
- 80’ of 1-¼” domestic hot water pipe in the boiler room
- 10’ of 1-½” domestic hot water pipe in the boiler room
- 10’ of ¾” domestic hot water pipe in the boiler room
- Boiler Expansion Tank – approximately 60 square feet of surface area
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($790) ($790) $2,200 $0 ($22,300) ($20,100) 10.1
Mendenhall River School 11 Energy Audit (February 2012)
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-11: Optimize Ventilation Systems
Purpose: The building utilizes constant flow heating and ventilation units to supply conditioned air
to interior spaces during the normal operational schedule, after school hours for activities,
and as needed on weekends. Overall, the building is over-ventilated. Energy will be saved
by properly ventilating the building.
The heat recovery wheel serving F-3 has very poor performance. In addition, the exhaust
air flow from Toilets 353/359 is excessive. Energy will be saved by replacing the wheel
with a new unit, reducing the exhaust air flow from Toilets 353/359, and adding the
exhaust from Toilets 154/155 to the heat recovery wheel.
Scope: Optimize the ventilation systems as follows and commission all air handling units to
perform as a properly integrated system when completed:
F-1 (Gym), F-2 (Admin), F-5 (Commons): Increase MAT from 60°F to 64°F.
F-3 (West Center Wing): Increase MAT from 58°F to 65°F.
F-4/EF-2 (Heat Recovery Wheel).
- Replace Heat Recovery Wheel.
- Decrease Toilets 353/359 exhaust from 700 to 350 cfm.
- Eliminate EF-3 and EF-4 and duct exhaust to the EF-2 heat recovery wheel.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($7,280) ($7,280) $83,500 $0 ($206,100) ($122,600) 2.5
EEM-12: Install Boiler and Electrical Room Heat Recovery
Purpose: A significant amount of heat is generated in the boiler room and by two transformers in
the electrical room. This heat is exhausted from the building. Energy will be saved if this
is heat is recovered and transferred to the gym.
Scope: Install a heat recovery unit in the boiler room. Circulate warm boiler room air through the
hot side of the unit and cool gym air through the cold side. Install an exhaust fan to
transfer warm electrical room air to the gym.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$120 ($3,220) ($3,100) $45,800 $2,000 ($101,100) ($53,300) 2.2
EEM-13: Replace Transformers
Purpose: The existing transformers are not TP-1 rated. Energy will be saved if these less-efficient
transformers are replaced with energy efficient models that comply with NEMA Standard
TP 1-2001.
Mendenhall River School 12 Energy Audit (February 2012)
EEM-13: Replace Transformers
Purpose: The existing transformers are not TP-1 rated. Energy will be saved if these less-efficient
transformers are replaced with energy efficient models that comply with NEMA Standard
TP 1-2001.
Scope: Replace the following less-efficient transformers with NEMA Standard TP 1-2001
compliant models:
- (2) 75 kVA
- (3) 30 kVA
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($2,310) ($2,310) $36,800 $0 ($45,400) ($8,600) 1.2
LOW PRIORITY
Low priority EEMs do not offer a life cycle energy savings and are not recommended.
EEM-14: Upgrade Motors to Premium Efficiency
Purpose: The equipment inspection identified six motors that could be upgraded with premium
efficiency models to save energy. They are:
- F-1 5 HP
- F-2 3 HP
- F-4 1 ½ HP
- F-5 1 ½ HP
- F-6 5 HP
- F-7 5 HP
Scope: Replace identified motors with premium efficiency motors.
Annual Costs Life Cycle Costs
Operating Energy Total Investment Operating Energy Total SIR
$0 ($240) ($240) $6,900 $0 ($4,800) $2,100 0.7
EEM-15: Variable Speed Pumping
Purpose: The boiler system currently utilizes fixed speed/constant horsepower pumps to deliver
heat throughout the building. These pumps do not vary energy consumption with heating
load. Energy will be saved if the fixed speed pumps are replaced with variable frequency
rated pumps and VFD’s were installed to control their operation.
Scope: Replace hydronic heating pumps with variable speed rated pumps and install VFD’s to
control their operation. This EEM will not offer a life cycle savings due to the modest
size of the pumps and relatively low cost electricity.
Mendenhall River School 13 Energy Audit (February 2012)
Section 4
Description of Systems
ENERGY SYSTEMS
This section provides a general description of the building systems. Energy conservation
opportunities are addressed Section 3, Energy Efficiency Measures.
Building Envelope
R-value
Component Description (inside to outside) Existing Optimal
Exterior Wall 5/8” Gyp. bd, 2”x6” stud, R-19 batt, ½” plywood, siding R-19 R-26
Roof 24” o.c. trusses, 5” rigid insulation roof buildup, 5/8” gyp. bd. R-20 R-54
Floor Crawlspace
Foundation 8” concrete w/ 2” perimeter insulation board R-10 R-20
Windows Single pane aluminum frame w/double pane storm windows R-1.5 R-5
Doors Steel doors w/ non-thermally broken frames R-1.5 R-5
Heating System
The building can be heated by one fuel oil boiler and one electric boiler to provide heat to seven air
handling unit systems, fan coil units, and perimeter hydronic systems. Currently the fuel oil boiler is
operating and the electric boiler is shut down. The heating system has the following pumps:
PU-1 supplies boiler loop water to the gym (F-1).
PU-5 supplies boiler loop water to the commons (F-5).
PU-6 supplies boiler loop water to the domestic hot water heater.
PU-7 is the domestic hot water recirculation pump.
PU-8 supplies boiler loop water to the west half of the school.
PU-9 is a spare.
PU-10 supplies boiler loop water to the east half of the school.
Mendenhall River School 14 Energy Audit (February 2012)
Ventilation Systems
Area
Fan
System Description
East Center Wing Gym F-1 12,000 cfm 5 hp constant volume air handling unit
consisting of an outside air damper, heating coil, mixing
box, filter section, and supply fan
East Center Wing
Administration
F-2 7,000 cfm 3 hp constant volume air handling unit
consisting of an outside air damper, heating coil, filter
section, and supply fan
Library/Classrooms F-3 12,000 cfm 5 hp constant volume air handling unit
consisting of an outside air damper, heating coil, filter
section, and supply fan
West Center Wing Heat F-4 3,100 cfm 1 ½ hp constant volume air handling unit
consisting of an outside air damper, heating coil, filter
section, and supply fan
East Center Wing Commons F-5 3,000 cfm 1 ½ hp constant volume air handling unit
consisting of an outside air damper, heating coil, filter
section, and supply fan
West Wing Classrooms F-6 11,000 cfm 5 hp constant volume air handling unit
consisting of an outside air damper, heating coil, filter
section, and supply fan
East Wing Classrooms F-7 11,000 cfm 5 hp constant volume air handling unit
consisting of an outside air damper, heating coil, filter
section, and supply fan
Multipurpose Room EF-1 18,000 cfm 5 hp constant volume fan supplying return air
to F-1 and relief air
West Center Wing Room 208 EF-2 2,200 cfm 3/4 hp constant volume exhaust fan for heat
wheel system
West Wing Room 154 EF-3 400 cfm 1/10th hp constant volume exhaust fan
West Wing Room 155 EF-4 400 cfm 1/10th hp constant volume exhaust fan
West Center Wing Rm J20 EF-5 400 cfm 1/10th hp constant volume exhaust fan
East Center Wing Rm 261 EF-6 400 cfm 1/10th hp constant volume exhaust fan
East Center Wing Rm J251 EF-7 400 cfm 1/10th hp constant volume exhaust fan
East Center Wing Rm 258 EF-8 400 cfm 1/10th hp constant volume exhaust fan
East Center Wing Rm 256 EF-9 400 cfm 1/10th hp constant volume exhaust fan
East Center Wing Rm 271 EF-10 180 cfm 1/50th hp constant volume exhaust air fan
East Center Wing Rm S270 EF-11 180 cfm 1/50th hp constant volume exhaust air fan
East Center Wing Rm ST266B EF-12 100 cfm 1/50th hp constant volume exhaust air fan
East Center Wing Rm ST266A EF-13 100 cfm 1/50th hp constant volume exhaust air fan
Mendenhall River School 15 Energy Audit (February 2012)
Ventilation Systems, continued
Area
Fan
System Description
East Center Wing Rm T267 EF-14 100 cfm 1/50th hp constant volume exhaust air fan
East Center Wing Rm 265 EF-15 400 cfm 1/10th hp constant volume exhaust fan
East Center Wing Rm 264 EF-16 400 cfm 1/10th hp constant volume exhaust fan
East Wing Rm 104 EF-17 400 cfm 1/10th hp constant volume exhaust fan
East Wing Rm 105 EF-18 400 cfm 1/10th hp constant volume exhaust fan
West Center Wing Rm 202 EF-19 400 cfm 1/10th hp constant volume exhaust fan
West Center Wing Rm 203 EF-20 400 cfm 1/10th hp constant volume exhaust fan
Crawlspace EF-21a 290 cfm 65 watt constant volume exhaust fan
Crawlspace EF-21b 290 cfm 65 watt constant volume exhaust fan
West Center Wing Rm 208 EF-22 400 cfm 1/10 hp constant volume exhaust fan
Domestic Hot Water System
Domestic hot water is heated by an indirect hot water heater and an electric hot water heater. The
indirect hot water heater is used throughout the entire school year while the boiler is operating.
During summer break the boiler and the indirect hot water heater are turned off, at which time the
electric hot water heater is placed on line to meet the domestic hot water demands of the school.
Automatic Control System
The building has a very limited DDC system to provide basic control functions for the operation of
the heating and ventilation systems. Energy can be saved through further optimization of fan system
scheduling combined with a retro-commissioning of the air handler systems.
Lighting
Interior lighting consists primarily of T12 fluorescent fixtures and metal halide lighting. Exterior
lighting consists primarily of metal halide lighting. Because lighting operational hours are controlled
by staff, operational costs for lighting with existing infrastructure are kept to a minimum. Much of the
energy that is saved by newer, more efficient lighting fixtures is in the form of heat. No
recommendations were made for the conversion of interior lighting to more efficient fixtures because
the heat generated by the current lighting fixtures is less expensive than heat produced by the boiler
system at Juneau fuel and electric rates.
Electric Equipment
Commercial equipment for food preparation is located in the kitchen prep area.
Mendenhall River School 16 Energy Audit (February 2012)
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.
Mendenhall River School 17 Energy Audit (February 2012)
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.
Mendenhall River School 18 Energy Audit (February 2012)
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 $0.084/kWh
General Inflation Rate 2% Electricity Inflation 3%
Fuel Oil Cost (2012) $3.80/gal Fuel Oil Inflation 6%
Mendenhall River School 19 Energy Audit (February 2012)
Appendix A
Energy and Life Cycle Cost Analysis
Mendenhall River School 20 Energy Audit (February 2012)
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
2012 $/gal Fuel Inflation 2012 $/gal
Fuel Oil $3.80 6% $4.03
Electricity $/kWh (2011)$/kW (2011)Inflation $/kWh (2012)$/kW (2012)
w/ Demand Charges $0.061 $10.62 3% $0.063 $10.94
w/o Demand Charges $0.114 -3% $0.117 -
EEM-3: Reduce Arctic Entries Temperatures
Energy Analysis
Component Area R-value ΔT Hours MBH kBtu η boiler Gallons
Wall 500 19.0 -10 6,480 -0.3 -1,705 68%-18
Door 378 2.0 -10 6,480 -1.9 -12,247 68%-130
-2.2 -13,952 -148
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Turn down thermostats 0 9 LS $15 $135
Energy Costs
Fuel Oil 1 - 25 -148 gal $4.03 ($16,914)
Net Present Worth ($16,800)
EEM-4: Operate Electric Hot Water Heater
Energy Analysis
Fuel Oil Boilers
Annual Gal η boiler Heat kBtu % Fuel Oil Boiler kBtu η boiler Annual Gal Savings, gal
300 68% 28,254 15% 4,238 68% 45 -255
Electric Boiler
% Electric kBtu η boiler kWh kW
85% 24,016 95% 7,409 -9
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Disable indirect hot water tank/enable electic hot water tank 0 4 hrs $60 $240
Energy Costs
Electric Energy (Effective Cost) 1 - 25 7,409 kWh $0.117 $24,659
Electric Demand 1 - 25 -108 kW $10.94 ($23,223)
Fuel Oil 1 - 25 -255 gal $4.03 ($29,114)
Net Present Worth ($27,400)
Mendenhall River School 21 Energy Audit (February 2012)
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: Replace Lavatory Aerators
Energy Analysis
Fixture Existing Proposed Uses/day Days Water,Gals % HW kBTU kWh
Lavatories 0.3 0.2 1,440 198 -51,322 80% -27,393 -8,029
-51,322 -8,029
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace lavatory aerators 0 17 ea $35 $595
Energy Costs
Water 1 - 25 -51 kgals $10.960 ($11,057)
Electric Energy (Effective Cost)1 - 25 -8,029 kWh $0.117 ($18,531)
Net Present Worth ($29,000)
EEM-6: Operate Electric Boiler
Energy Analysis
Fuel Oil Boilers
Annual Gal η boiler Heat kBtu % Fuel Oil Boiler kBtu η boiler Annual Gal Savings, gal
14,400 68% 1,356,192 15% 203,429 68% 2,160 -12,240
Electric Boiler
% Electric kBtu η boiler kWh
85% 1,152,763 95% 355,637
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Return electric boiler to service 0 1 ea $5,000 $5,000
Annual Costs
Electric boiler maintenance 1 - 25 4 hrs $60.00 $4,086
Fuel oil boiler maintenance 1 - 25 -8 hrs $60.00 ($8,173)
Energy Costs
Electric Energy (Effective Cost) 1 - 25 355,637 kWh $0.115 $1,160,413
Fuel Oil 1 - 25 -12,240 gal $4.03 ($1,397,463)
Net Present Worth ($236,100)
Gallons per Use
Mendenhall River School 22 Energy Audit (February 2012)
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 Program Clocks on Exhaust Fans
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
EF-7 Existing -400 0.25 40% -0.04 70%0 1,152 -48
EF-19 Optimized -400 0.25 40% -0.04 70%0 1,152 -48
EF-20 Existing -400 0.25 40% -0.04 70%0 1,152 -48
0 -145
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler Gallons
EF-7 Existing -400 40 70 -13 1,152 -14,930 68%-159
EF-19 Optimized -400 40 70 -13 1,152 -14,930 68%-159
EF-20 Existing -400 40 70 -13 1,152 -14,930 68%-159
-44,790 -476
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install program clocks 0 3 ea $500 $1,500
Energy Costs
Electric Energy 1 - 25 -145 kWh $0.063 ($179)
Fuel Oil 1 - 25 -476 gal $4.03 ($54,297)
Net Present Worth ($53,000)
EEM-8: Operate Boiler on Low Fire
Energy Analysis
Annual Gal % Savings Savings, Gal
14,396 -1.0% -144
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Institute low/high contorl strategy 0 1 LS $500 $500
Annual Costs
Low/High control operation 1 - 25 1 hrs $60.00 $1,022
Energy Costs
Fuel Oil 1 - 25 -144 gal $4.03 ($16,436)
Net Present Worth ($14,900)
Mendenhall River School 23 Energy Audit (February 2012)
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: Install Exhaust Fan Timer Switches
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
EF-6 Existing -400 0.25 40% -0.04 70%0 576 -24
EF-8 Optimized -400 0.25 40% -0.04 70%0 576 -24
EF-9 Existing -400 0.25 40% -0.04 70%0 576 -24
EF-14 Optimized -100 0.25 40% -0.01 70%0 576 -6
EF-15 Existing -400 0.25 40% -0.04 70%0 576 -24
EF-16 Optimized -400 0.25 40% -0.04 70%0 576 -24
0 -127
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler Gallons
EF-6 Existing -400 40 70 -13 576 -7,465 68%-79
EF-8 Optimized -400 40 70 -13 576 -7,465 68%-79
EF-9 Existing -400 40 70 -13 576 -7,465 68%-79
EF-14 Optimized -100 40 70 -3 576 -1,866 68%-20
EF-15 Existing -400 60 70 -4 576 -2,488 68%-26
EF-16 Optimized -400 62 70 -3 576 -1,991 68%-21
-28,740 -305
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Install timer switch 0 6 ea $250 $1,500
Energy Costs
Electric Energy 1 - 25 -127 kWh $0.063 ($157)
Fuel Oil 1 - 25 -305 gal $4.03 ($34,841)
Net Present Worth ($33,500)
EEM-10: Install Pipe Insulation
Energy Analysis
Service Size Length Bare BTUH Insul BTUH Factor kBtu η boiler Gallons
Heating 0.75 2 74 11 25% -276 68%-3
Heating 1.50 15 126 15 25% -3,646 68%-39
Heating Ex Tank 30 250 30 25% -14,454 68%-153
DHW 0.75 10 25 4 25% -460 68%-5
DHW 1.25 80 38 5 25% -5,782 68%-61
DHW 1.50 10 42 6 25% -788 68%-8
-195
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
3/4"0 12 lnft $5 $60
1-1/4"0 80 lnft $7 $560
1-1/2"0 25 lnft $8 $200
Expansion tank 0 1 ls $400 $400
Estimating contingency 0 15%$183
Overhead & profit 0 30%$421
Design fees 0 10%$182
Project management 0 8%$161
Energy Costs
Fuel Oil 1 - 25 -195 gal $4.03 ($22,277)
Net Present Worth ($20,100)
Mendenhall River School 24 Energy Audit (February 2012)
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: Optimize Ventilation Systems
Energy Analysis
Fan Case CFM ΔP η, fan BHP η, motor kW Hours kWh
E-3 Existing -400 0.50 40% -0.1 70% -0.1 1,620 -136
E-4 Existing -400 0.50 40% -0.1 70% -0.1 1,620 -136
0 -272
Ventilation SA CFM MAT T,room MBH Hours kBtu η boiler Gallons
F-1 Existing -12,000 62 70 -104 1,620 -167,962 68%-1,783
Optimized 12,000 64 70 78 1,620 125,971 68%1,338
F-2 Existing -7,000 62 70 -60 1,620 -97,978 68%-1,040
Optimized 7,000 64 70 45 1,620 73,483 68%780
F-5 Existing -3,000 62 70 -26 1,620 -41,990 68%-446
Optimized 3,000 64 70 19 1,620 31,493 68%334
-76,982 -817
F-3/F-4 Heat Recovery SA CFM MAT T,room MBH Hours kBtu η boiler Gallons
F-4 Existing -3,100 50 70 -67 1,620 -108,475 68%-1,152
Optimized 3,300 60 70 36 1,620 57,737 68%613
E-3/E-4 Existing -800 40 70 -26 1,620 -41,990 68%-446
-92,729 -985
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Modify controls 0 6 pts $1,000 $6,000
Replace E-3 and E-4 with exhaust grille 0 1 LS $1,000 $1,000
Replace heat wheel 0 1 LS $20,000 $20,000
Rebalance E-2, F-4 0 1 LS $5,000 $5,000
Exhaust duct to heat wheel 0 1 LS $15,000 $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
Energy Costs
Electric Energy 1 - 25 -272 kWh $0.063 ($335)
Fuel Oil 1 - 25 -1,802 gal $4.03 ($205,736)
Net Present Worth ($122,600)
Mendenhall River School 25 Energy Audit (February 2012)
Alaska Energy Engineering LLC Energy and Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Building Name
EEM-12: Install Boiler/Electric Room Heat Recovery
Energy Analysis
Boiler Room
Heat Recovery
Boiler gph Jacket Loss MBH Hours Loss, kBtu Factor Recovery, kBtu η boiler Gallons
18 -1.0% -24 6,480 -157,371 40% -62,949 84%-541
Fan Energy
MBH ΔT CFM ΔP η, fan # Fans Hours kW kWh
24 12 1,874 1.50 35%2 6,480 1.9 12,210
Electrical Room
Transformer heat
kVA ηold MBH Hours Loss, kBtu Factor Recovery, kBtu η boiler Gallons
150 98.0% -10 8,760 -89,667 70% -62,767 84%-540
Fan Energy
MBH ΔT CFM ΔP η, fan # Fans Hours kW kWh
10 12 790 1.00 35%1 8,760 0.3 2,319
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
2,000 CFM HRV 0 2,000 cfm $8 $16,000
Ductwork and grilles 0 1 LS $4,000 $4,000
800 cfm exhaust fan 0 800 cfm $1 $800
Ductwork and grilles 0 1 LS $2,500 $2,500
Remove louver and patch exterior wall 0 1 LS $500 $500
Electrical 0 2 LS $1,000 $2,000
Estimating contingency 0 15%$3,870
Overhead & profit 0 30%$8,901
Design fees 0 10%$3,857
Project management 0 8%$3,394
Annual Costs
HRV maintenance 1 - 25 2 hrs $60.00 $2,043
Energy Costs
Electric Energy 1 - 25 14,529 kWh $0.063 $17,945
Electric Demand 1 - 25 20.1 kW $10.94 $4,330
Fuel Oil 1 - 25 -1,081 gal $4.03 ($123,373)
Net Present Worth ($53,200)
Mendenhall River School 26 Energy Audit (February 2012)
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-13: Upgrade Transformers
Energy Analysis
Number kVA ηold ηnew KW kWh
3 30 96.8% 98.4% -1.4 -12,614
2 75 97.4% 98.7% -2.0 -17,082
-3.4 -29,696
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs
Replace transformer, kVA 30 0 3 LS $4,400 $13,200
Replace transformer, kVA 75 0 2 LS $6,500 $13,000
Overhead & profit 0 30%$7,860
Project management 0 8%$2,725
Energy Costs
Electric Energy 1 - 25 -29,696 kWh $0.063 ($36,678)
Electric Demand 1 - 25 -41 kW $10.94 ($8,747)
Net Present Worth ($8,600)
EEM-14: Upgrade Motors
Energy Analysis
Equip Number HP ηold ηnew kW Hours kWh
F-4 1 1.5 79.1% 86.5% -0.08 1,620 -134
F-5 1 1.5 79.1% 86.5% -0.08 1,620 -134
F-2 1 3 81.4% 89.5% -0.18 1,620 -294
F-1 1 5 83.3% 89.5% -0.23 1,620 -375
F-6 1 5 83.3% 89.5% -0.23 1,620 -375
F-7 1 5 83.3% 89.5% -0.23 1,620 -375
-1.0 -1,686
Life Cycle Cost Analysis Year Qty Unit Base Cost Year 0 Cost
Construction Costs HP
Replace motor 1.5 0 2 LS 955 $1,910
Replace motor 3 0 1 LS 1,080 $1,080
Replace motor 5 0 3 LS 1,290 $3,870
Energy Costs
Electric Energy 1 - 25 -1,686 kWh $0.063 ($2,082)
Electric Demand 1 - 25 -12 kW $10.94 ($2,685)
Net Present Worth $2,100
Mendenhall River School 27 Energy Audit (February 2012)
Appendix B
Energy and Utility Data
Mendenhall River School 28 Energy Audit (February 2012)
Alaska Energy Engineering LLC Billing Data
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Mendenhall River Elementary School
ELECTRIC RATE
Electricity ($ / 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 34,038
Feb 76,640 163 79,720 180 74,800 171 76,960 182 44,448
Mar 70,800 169 77,160 178 74,320 182 79,360 181 44,883
Apr 73,800 163 71,040 179 73,200 182 74,280 182 38,395
May 25,400 164 16,840 162 19,960 178 14,960 36 38,848
Jun 11,480 40 8,040 28 9,160 40 7,080 35 25,300
Jul 10,440 41 8,240 36 8,640 40 8,600 33 11,793
Aug 66,320 168 57,440 169 47,720 181 45,400 163 9,675
Sep 79,160 162 63,200 162 70,680 167 64,200 161 35,523
Oct 79,480 161 80,600 178 72,880 177 81,840 169 43,000
Nov 92,520 166 79,240 181 84,600 182 90,480 184 40,760
Dec 79,600 181 78,480 182 76,880 182 72,800 182 40,718
Total 375,010 382,570 491,460 380,470 407,378
Average 31,251 131 31,881 129 40,955 142 31,706 126 33,948
Load Factor 32.7% 33.9% 39.5% 34.4% 132
ELECTRIC BILLING DETAILS
Month Energy Demand Cust & Tax Total Energy Demand Cust & Tax Total % Change
Jan 2,006 2,259 99 4,365 1,985 2,235 99 4,319 -1.0%
Feb 3,035 2,254 99 5,388 2,558 2,145 99 4,802 -10.9%
Mar 3,418 2,281 99 5,798 2,573 2,101 99 4,773 -17.7%
Apr 3,197 2,269 99 5,565 2,019 2,011 99 4,129 -25.8%
May 3,411 2,225 99 5,736 2,036 1,952 99 4,088 -28.7%
Jun 2,107 1,356 99 3,562 1,473 1,239 99 2,811 -21.1%
Jul 930 834 99 1,863 593 239 99 931 -50.0%
Aug 673 585 99 1,357 671 386 99 1,156 -14.8%
Sep 2,966 1,360 99 4,426 2,263 1,247 99 3,609 -18.5%
Oct 3,367 1,357 99 4,823 2,341 1,348 99 3,788 -21.5%
Nov 2,475 2,254 99 4,828 2,255 2,115 99 4,469 -7.4%
Dec 2,443 2,182 99 4,724 2,481 2,102 99 4,682 -0.9%
Total $ 30,028 $ 21,216 $ 1,191 $ 52,435 $ 23,247 $ 19,120 $ 1,191 $ 43,557 -16.9%
Average $ 2,502 $ 1,768 $ 99 $ 4,370 $ 1,937 $ 1,593 $ 99 $ 3,630 -16.9%
Cost ($/kWh)$0.107 53% 44% 3% $0.114 7.3%
Electrical costs are based on the current electric rates.
2010 2011
2010
AEL&P Electric Rate 24 On-Peak
Nov-May
Off-peak
Jun-Oct
Month 2008 2009 2010 Average
Mendenhall River School 29 Energy Audit (February 2012)
Alaska Energy Engineering LLC Annual Electric Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Mendenhall River Elementary School
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
2008
2009
2010
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
2008
2009
2010
2010
Mendenhall River School 30 Energy Audit (February 2012)
Alaska Energy Engineering LLC Electric Cost
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Mendenhall River Elementary School 2011
$ 0
$ 1,000
$ 2,000
$ 3,000
$ 4,000
$ 5,000
$ 6,000
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
Mendenhall River School 31 Energy Audit (February 2012)
Alaska Energy Engineering LLC Annual Fuel Oil Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Mendenhall River Elementary School
Year 2008 2009 2010 2011 Average
Fuel Oil - Heat 13,448 11,727 17,983 14,424 14,396
Degree Days 9,282 9,093 9,284 9,013
0
2,000
4,000
6,000
8,000
10,000
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
2008 2009 2010 2011 Degree DayGallonsYear
Annual Fuel Oil Use
Fuel Oil ‐ Heat Degree Days
Mendenhall River School 32 Energy Audit (February 2012)
Alaska Energy Engineering LLC Annual Water Consumption
25200 Amalga Harbor Road Tel/Fax: 907-789-1226
Juneau, Alaska 99801 jim@alaskaenergy.us
Mendenhall River Elementary School
Year Water
2007 408,000
2008 360,000
2009 372,000
2010 360,000
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
2007 2008 2009 2010Gallons of WaterYear
Annual Water Use
Mendenhall River School 33 Energy Audit (February 2012)
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 58,669 $1.66 58
Electricity $0.114 $35.32
nterruptible Electric H $0.107 $32.95
Source Cost
Electricity 407,378 kWh $46,600 1,400 41%
Fuel Oil 14,396 Gallons $50,700 2,000 59%
Totals $97,300 3,400 100%
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 Interruptible Electric HeatCost $ / MMBtuCost of Heat Comparison
Mendenhall River School 34 Energy Audit (February 2012)
Appendix C
Equipment Data
Mendenhall River School 35 Energy Audit (February 2012)
MotorHP / Volts / RPM / EfficB-1 Boiler Room Fuel Oil BoilerWeil Mclain H-1086 2040 MBHB-2 Boiler Room Electric BoilerPrecision W-1 1430 MBH 480 V/240 KWF-1 E Central Wing 455 GymAir Care 271-LP 12,000 CFM 5 HP/ 480 V/ 1740 RPM/ 87.5%F-2 E Central Wing 455 AdministrationPace A20-AFS1 7,000 CFM 3 HP/ 480 V/ 1750 RPM/ 86.5%F-3 W Central Wing 208 Library / Classrooms Pace 27DWD1 12,000 CFM 5 HP/ 480 V/ 1750 RPM/ 89.5%F-4 W Central Wing 208 Reclaimed HeatGreenheck 50B-18-15 3,100 CFM 1 1/2 HP/ 480 V/ 1750 RPM/ 84%F-5 E Central Wing 455 CommonsAir Care 121-1-LP 3,000 CFM 1 1/2 HP/ 480 V/ 1750 RPM/ 84%F-6 Fan Room 6 West Wing Classrooms Pace 22AF 11,000 CFM 5 HP/ 480 V/ 1750 RPM/ 87.5%F-7 Fan Room 7 East Wing Classrooms Pace 22AF 11,000 CFM 5 HP/ 480 V/ 1740 RPM/ 87.5%EF-1 Multi Purpose Room Relief/Return Pace Plug Fan 18,000 CFM 5 HP /480 V/1740 RPM/ 87.5%EF-2W Central Wing 208Heat WeelGreenheck SCB 187 2,200 CFM 3/4 HP/ 480 V/ 1725 RPM/ 76%EF-3 W Wing 154 Rest RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-4 W Wing 155 Rest RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-5W Central Wing J201Janitor RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-6 E Central Wing 261 Copy RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-7 E Central Wing J251 Janitors RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-8 E Central Wing 258 Kitchen Preparation Pace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-9 E Central Wing 256 P.E. StoragePace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-10 E Central Wing 271 Server RoomPace DD-250 GV 180 CFM 1/50 HP/ 115 VEF-11E Central Wing S-270Server RoomPace DD-250 GV 180 CFM 1/50 HP/ 115 VEF-12E Central Wing ST-266BRest RoomPace DD-150 GV 100 CFM 1/50 HP/ 115 V Mendenhall River Elementary School- Major Equipment InventoryCapacityNotesUnit IDLocation Function Make Model
Mendenhall River School 36 Energy Audit (February 2012)
MotorHP / Volts / RPM / Effic Mendenhall River Elementary School- Major Equipment InventoryCapacityNotesUnit IDLocation Function Make ModelEF-13E Central Wing ST-266ARest RoomPace DD-150 GV 100 CFM 1/50 HP/ 115 VEF-14E Central Wing T-267Nurse Rest RoomPace DD-150 GV 100 CFM 1/50 HP/ 115 VEF-15 E Central Wing 265 LoungePace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-16 E Central Wing 264 ConferencePace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-17 E Central Wing 104 Rest RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-18 E Central Wing 105 Rest RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-19 W Central Wing 202 Rest RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-20 W Central Wing 203 Rest RoomPace DD-450 GV 400 CFM 1/10 HP/ 115 VEF-21A Crawl Space Crawl SpaceTradewind AF 7M 290 CFM 65 Watt/ 115 VEF-21B Crawl Space Crawl SpaceTradewind AF 7M 290 CFM 65 Watt/ 115 VEF-22 W Central Wing 208 Custodial Storage Exhaust Pace DD-450 GV 400 CFM 1/10 HP/ 115 VPU-1 E Central Wing 455 Gym Heat and Vent B&G37.5 GPM 1/6 HP/ 480 V/PU-2 E Central Wing 455 Not UsedB&GPU-3 E Central Wing 455 Not UsedB&GPU-4 E Central Wing 455 Not UsedB&GPU-5 E Central Wing 455 Commons Heat and Vent B&G10 GPM 1/6 HP/ 115 V/ 1750 RPMPU-6 Boiler Room Water HeaterTeel 1P965C 27 GPM 1/6 HP/ 115 V/ 1750 RPMPU-7 Boiler Room Hot Water Recirculation B&G NBF-22 10 GPM 1/6 HP/ 115 V/ 1750 RPMPU-8 Boiler Room West WingB&G PD 37 50 GPM 3/4 HP/ 480 V/ 1750 RPM/ 76%PU-9 Boiler Room Back UpB&G PD 37 50 GPM 3/4 HP/ 480 V/ 1750 RPM/ 76%PU-10 Boiler Room East WingB&G PD 37 35 GPM 3/4 HP/ 480 V/ 1750 RPM/ 76%
Mendenhall River School 37 Energy Audit (February 2012)
MotorHP / Volts / RPM / Effic Mendenhall River Elementary School- Major Equipment InventoryCapacityNotesUnit IDLocation Function Make ModelPU-11 Boiler Room Sump PumpPaco PIP-700 36 GPM 1/3 HP/ 115 VDHW-1 Boiler Room Indirect Domestic Hot WaterSuperstarSSU-119C 120 GallonDHW2 Boiler RoomElectric Hot Water HeaterRheem 1009E 00221 119 Gallon 36KW/ 98% EfficientT-1 Electrical Room Transformer Square D 7573 HB 75 KVA 80 Degree Temperature Rise Non TP RatedT-2 Electrical Room Transformer Westinghouse T83-C-07114 75 KVA Non TP RatedT-3 Fan 7 Room Transformer Westinghouse DT-3 30 KVA Non TP RatedT-4 Supply Room Transformer Westinghouse DT-3 30 KVA Non TP RatedT-5 Fan Room 6 Transformer Westinghouse DT-3 30 KVA Non TP RatedAC-1 Boiler Room Air Compressor Manchester CRNF-0516 150 Gallon 2 HP/480 V/1725 RPM/ 80% Two Motors
Mendenhall River School 38 Energy Audit (February 2012)
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
Mendenhall River School 39 Energy Audit (February 2012)