Attachment 1 - Final Investment Grade Audit
ESCO Contract — Nashua Schools & EEI, Inc 11/22/2019
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ENE Systems, Inc./Energy Efficient Investments, Inc.
Investment Grade Audit
FOR:
Nashua School District
Prepared by:
Michael Davey, CEM
Date: December 05, 2019
BEE] SENE
ENERGY EFFICIENT INVESTMENTS INC. EFFICIENT INVESTMENTS INC.
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REDUCING THE OPERATING AND ENERGY COSTS OF YOUR FACILITY
Table of Contents
Executive SUM MALY vaccceseeeeeceseeeeeeeeseeeeeeueeaseeeueeeeeseueeeeeseuaeeausauaeeansanas
ECM Matrix wiccccccceeccceceeeceeeeeeeeeeenaeeeeeaeeeesaeeuneeneueuaneeueeaeeueeeeeeugeeeeueeaneegs
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Utility AM@lySIS .....cccccseeceeeseecseeeseeceeaeaeueeeasaeaeeeagueeeesuaueeeuauaueeseanaeaeaesnsD
ECONOMIC ANALYSIS .icccccceceseceeeeeeeeeeeseeeaeeeeuaeaeaeeuaeaeaueeauaeaeaeanaeaeanaeersnssO
7
Energy Conservation Measures DEPP
ENE Systems, Inc. / Energy Efficient Investments, Inc.
~Confidential & Proprietary~
Executive Summary
EEI is located in Merrimack, NH, and has a proven track record of designing and
implementing energy improvements to mechanical systems, building controls systems,
insulation, and renewable systems. EEI is also an approved energy management contractor
with, Eversource, Liberty Utilities, and Unitilin New Hampshire.
EEI has developed a plan which could reduce annual energy expenditures in the
district by more than $466,719.70
EEI in its role as Energy Service Company (ESCO) has agreed to develop an energy project
targeting energy savings at the locations identified below:
Building Location
Nashua North High School 8 Titan Way, Nashua, NH 03063
Nashua South High School 36 Riverside St. Nashua, NH 03062
The development of every energy project starts with the initial energy assessment which
includes a site visit and the collection of utility and operational costs for each location. The
Preliminary IGA entailed defining measures, budgetary costs, and estimated savings values
by measure for each building. This Investment Grade Audit document finalizes these
findings and the costs associated with them.
EEI has prepared bid packages for each measure through the
solicitation of competitive bids from respected local contractors.
These bids were tallied, and the contractor cost has replaced the
budgetary cost established in the Preliminary Investment Grade
Audit. The Final Investment Grade Audit will be presented to the
Nashua School District for acceptance as part of the Energy
Performance Contract.
ENE Systems, Inc. / Energy Efficient Investments, Inc.
~Confidential & Proprietary~
ECM Matrix
ECM Matrix
Upgrade
ransformers
Commissioning
Hot Water
argeted Balancing
Hood
In Coolers
otal NNHS
Upgrade
ransformers
Commissioning
Hot Water
argeted Balancing
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otal NSHS
Cost for Installed Energy Savings potential Rebates “wal Hectric
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Al?
$1,077,300
$50,000.
$577,371.
$262, 080.
700.
$165,000.
$75,000.
000.
$35,000.
$3690,868.
$1
$1,197,000
$50,000.
$430,920.
$262, 080.
$119,700.
$165,000.
$75,000.
000.
$35,000.
$3807,942.0
$27,000.
$20,000.
$22,000.
$35,000.
$4,000
$5,000
$5,000
$410,500.
$30,000.
$20,000.
$20,000.
$35,000.
$0
$4,000
$0
$5,000
$234, $444,000.
Anal Ntural CO2 Emmisions
Gas Savings Reduction ATi [Bb rel
feud) (Tons)
Total
$7,498, 810.00
$466,719.70 $854,500.00
2980,784 mac ail 119
ENE Systems, Inc. / Energy Efficient Investments, Inc.
~Confidential & Proprietary~
Utility Analysis
The utility bills were analyzed to better understand the energy use of each building. Each
building utilizes natural gas provided by Liberty Utilities for HVAC heating, domestic hot
water heating, and cooking. The electricity is provided by Eversource. The utility data was
analyzed over a three year period, 2016-2018, and shows an average Energy Use Index
(EUI) of 65 at the Nashua North High school, and 62 at the Nashua South High School. The
EUI is used to compare energy consumption per square foot of building space. According to
the U.S. Department of Energy, the average EUI fora K-12 Facility is 48.5. This means that
both schools use approximately 35% more energy than the average K- 12 facility. Given this
information, we believe there are energy saving opportunities at each school. See the table
below summarizing the annual energy consumption data.
Building Summary Information
Project Name: Nashua North & Nashua South High Schools
Annual Utility Data
Average Use
2016-2018
Nashua North
HS. Nat Gas (therms) 141,816
Elec (kWh) 3,948,662
Nashua South
HS. Nat Gas (therms) 141,589
Elec (kWh) 3,725,082
Contract Utility Rates
Natural Gas Therm Rate 51.00
Electricity Electric Rate $0.15
Nashua, NH Balance Point (65°)
HDD 6071
CDD 1050
ENE Systems, Inc. / Energy Efficient Investments, Inc.
~Confidential & Proprietary~
Economic Analysis
Making good economic decisions requires analysis of available information and
understanding the monetary value of time. A Discounted Life Cycle Cost Analysis
(DLCCA) is very useful for this type of analysis when multiple alternatives exist. This is
the Federal Energy Management Program (FEMP) approved method of analysis and is
used to aid in decisions that are based on the most favorable economic outcome. The
Nashua School District can see the estimated time it will take for this energy project to
payback shown on the ECM Matrix on page 3.
The key assumptions EEI used in our Economic Analysis include the baseline gas and
kWh use which are the average fiscal year totals from2016 - 2018. Building interior
lighting fixtures were assumed to run 2,000 hours per year, this is based on observation
and interviews with staff. Exterior fixtures were assumed to run 4,380 hours per year.
Additionally, the estimated energy savings calculations are dependent upon the building
HVAC controls being controlled to a defined set of temperatures. These standards of
comfort can be seen below.
EEI, Inc.
Nashua School District
Occupied Unoccupied
Building Setpoint °F Heating Tire) tai marl]
Nashua High School North
Classrooms 68 60 72 80
Media Center 68 60 72 80
Cafeteria/Kitchen 68 60 72 80
Auditorium 68 60 72 80
Offices 68 60 72 80
Gym 65 60 72 80
Library 68 60 72 80
Hallways 68 60 72 80
Nashua High School South
Classrooms 68 60 72 80
Media Center 68 60 72 80
Cafeteria/Kitchen 68 60 72 a0
Auditorium 68 60 Ta 80
Offices 68 60 ee 80
Gym 68 60 72 80
Library 68 60 72 80
Hallways 68 60 72 80
Notes:
1. All setpoints and times are suggested, Actual values to be determined after discussions with Nashua School District.
2. EE! will program a General Building Override button. This will allow the building operator to override the building schedule for non-scheduled events (such as snow days)
ENE Systems, Inc. / Energy Efficient Investments, Inc.
~Confidential & Proprietary~
Energy Conservation Measures
In this section of the document we will define the Energy Conservation Measures we have
evaluated for this project. Then we will define the measures on a building by building basis.
Careful consideration was given to each measure and its interaction withthe overall building
performance.
General ECM Descriptions
Nashua North High School
ECM 1 - LED Lighting
The schools currently utilize a combination of T8 and T5 fluorescent lighting. EEI proposes
replacing the existing fixtures with new LED lighting. EEI performed a detailed survey of the
interior and exterior spaces in order to identify opportunities in which we can improve
lighting quality, reduce maintenance costs, and save energy.
The existing lighting demand (kW) per fixture, hours of operation, fixture quantities, and
recommended retrofits are based on the physical inspection and site visits conducted by EEI
in 2019. As a result of the survey and analysis, EEI has developed a high efficiency lighting
upgrade project that will provide the schools listed with new LED fixtures with controls,
resulting in guaranteed annual energy savings and a reduction in electrical demand.
LED type lighting provides significant illumination, has longer life expectancy, increased
savings in electric consumption, and provides dimming capabilities. Also, standardizing all
fixtures will reduce future maintenance requirements.
LED fixtures in a school environment have an estimated life of more than 20 years. There is
significant maintenance savings when LED fixtures are used due to their longer lifespan.
All light energy eventually converts to heat. The conversion to higher efficiency LED fixtures
will reduce the building’s lighting energy intensity (kW/sq.ft), therefore impacting the HVAC
heating and cooling loads. Converting to LED lighting will eliminate 2,799 mmBTU waste
heat annually. The reduction in lighting waste heat will increase the HVAC load during
heating season, approximately 11,983 therms annually. Conversely, the HVAC load will
decrease in the cooling season, approximately 55,925 kWh annually. The net HVAC utility
impact is an increase in cost of approximately $3,594. This increase in cost has been
subtracted fromthe energy savings for the ECM. Please see below forthe formulas used to
calculate the net savings affect.
HVAC Heating Load Increase = (Net Annual Interior LED Lighting kWh Savings * Btu
Conversion Factor * Therm Conversion Factor* % of Time HVAC Systemis Heating * Utility
Rate per Therm) / (Heating System Efficiency)
HVAC Cooling Load Decrease = Net Annual Interior LED Lighting kWh Savings * Btu
Conversion Factor * Cooling Tons Conversion Factor * % of Time HVAC Systemis Cooling *
Cooling System Efficiency * Utility Rate per kWh
Assumptions:
o Net Annual Interior LED Lighting kWh Savings = 820,956 kWh
o % of time HVAC Systemis Heating = 3000 hours / 8760 hours = 35%
o % of time HVAC Systemis Cooling = 3000 hours / 8760 hours = 35%
o Heating SystemEfficiency = 80%
o Cooling System Efficiency = .7 kW/ton
o Utility Rate per Therm = $1.00/therm
o Utility Rate per kWh = $.15/kWh
Scope of Work:
Install (2,953) LED 2x4 and 2x4 retrofit fixtures with Spacewise control and wireless
dimming capability
Install (271) LED high bay fixtures with Spacewise control and wireless dimming capability
Install (461) LED recessed can fixtures
Install (2,310) LED tubes and (1,350) LED drivers
Install (139) LED lamps
Install (180) LED round decorative fixtures
ECM 2 —- Controls Upgrade
EEI proposes installing a complete DDC system as an extension of the existing N4
Enterprise Supervisor.
Scope of work:
e Demo the existing VAV controllers, keeping the existing communication wiring
operational for the existing controllers.
e New BACnet IP DDC controllers, new space sensors with CO2, and new discharge
air sensors. Reuse existing control valves. Provide programming to reduce
minimum airflow when space temperature and CO2 levels are satisfied.
e Assistance in displaying building analytics software. Review analytics reports with
the team and retro-commission systems to remedy problem zones. Repeat this
monthly to fine tune the building HVAC systems.
e Assistance to the balancing contractor to calibrate VAVs, airflow stations, and
AHUs.
e Network controller hardware and software updates as needed.
ECM 3 -— Weatherization
EEI completed a detailed building audit. Suspected air leakage locations were verified
and opportunities to improve building performance and save energy were found. Air
leakage is caused by pressure differences subject to variations in wind velocity and
HVAC systems. In order to control heating and cooling loads, and allow the mechanical
systems to operate effectively, pressure differences from the outdoor environment to
the indoor building spaces must be controlled. The best way to do this is by tightening
the building envelope through insulating and air sealing. This will extend the life cycle
of the building by protecting it from the elements and minimizing moisture carried by
air which penetrates the building. Also, insulation and air sealing increases thermal
performance of the building and the comfort, health and safety of the building
occupants.
Scope of work:
Inspect exterior doors for deficiencies to the weather stripping and door sweeps. Install
new weather stripping and door sweeps as needed.
ECM 4 - Transformers
EEI evaluated the electrical systems of the s chool buildings and determined that the
existing transformers at Nashua North High School are standard efficiency models that
are not designed to handle the loads of modern facilities. The most common efficiency
for commercial and industrial transformers supplying linear loads in the 30-150 kVA
range is 95%, as compared to 98% for a high efficiency model. Further, conventional
transformer losses, which are non-linear, increase by 2.7 times when _ feeding
computer loads.
EEI recommends the replacement of existing inefficient transformers in order to improve
the energy efficiency ofthe electricaldistribution systems through the replacement
of the transformers with new high efficiency units. The scope of work for this measure
would include upgrading:
32 Transformers
(5) 15 kVA
(4) 30 kVA
(2) 45 kVA
(1) 75 kVA
(6) 112.5 kVA
(1) 145 kVA
(1) 150 kVA
(1) 175 kVA
(3) 220 kVA
(4) 225 kVA
(2) 300 kVA
(2) 500 kVA
ECM 5 -— Retro Commissioning
This is an allowance for an engineering and maintenance team to install, repair, and
replace any damaged existing to remain equipment. Existing AHUs will include software
revisions to reduce energy consumption. Includes 5 years of analytics reports.
ECM 6 — Mini Splits
EEI proposes removing the (19) existing Mitsubishi ductless splits.
Furnish and install (19) new Mitsubishi condensing units of the same capacity of the
existing system. Counts are as follows: (7) 1-tonceiling cassette systems, (3) 1.5-ton
ceiling cassette systems, (1) 2-tonceiling cassette system. (1) 1-ton wall mounted
system, (6) 1.5-ton wall systems, (1) 2-ton wall mounted system. New units will be
furnished with wind baffles for low ambient cooling and new wall mounted thermostats.
