Download - Public Schools HVAC Assessment
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Final Report
Town of Andover
Public Schools HVAC Assessment
September 2020
Submitted By: NV5
Carol Donovan, Director Michael Papagni, PE
200 Brickstone Sq. #201 Andover, MA 01810
Submitted To: Town of Andover Andrew Flanagan, Town Manager Sheldon Berman, Superintendent Janet Nicosia, Director of Facilities 5 Campanelli Drive Andover, MA 01810
Table of Contents
Town of Andover Page 1 of 39
School HVAC Assessments September 28, 2020
Section Page
1.0 Executive Summary ...................................................................................................................... 2
2.0 HVAC Assessment Methodology .................................................................................................. 9
3.0 Facility Descriptions and Assessments ..................................................................................... 14
3.1 Andover High School................................................................................................................... 14
3.2 Doherty Middle School ............................................................................................................... 16
3.3 West Middle School .................................................................................................................... 18
3.4 Wood Hill Middle School ............................................................................................................ 20
3.5 Bancroft Elementary School ...................................................................................................... 22
3.6 High Plain Elementary School ................................................................................................... 25
3.7 Sanborn Elementary School ...................................................................................................... 27
3.8 South Elementary ....................................................................................................................... 29
3.9 West Elementary School ............................................................................................................ 31
3.10 Shawsheen Preschool ................................................................................................................ 34
4.0 General Observations ................................................................................................................. 36
5.0 Recommendations and Next Steps........................................................................................... 38
Executive Summary
Town of Andover Page 2 of 39
School HVAC Assessments September 28, 2020
1.0 Executive Summary
Introduction and Project Overview:
NV5 was retained by the Town of Andover to assess the current status of the HVAC systems
serving their public schools. The school district consists of ten (10) schools: one preschool, five
elementary schools, three middle schools and one high school. Woodhill Middle School and
High Plain Elementary School were constructed as one building but act as two schools with
shared common areas. The list of schools assessed with approximate gross square footage and
year built is provided below.
Table 1 – School Data Summary
Building Name
Gross
Square
Footage
Number
of Stories
Year
Built
Year of Last
Renovation
Andover High School 315,000 3 1966 1995
Doherty Middle School 125,000 2 1951 1995
West Middle School 106,000 2 1956 1990
Bancroft Elementary School 105,000 3 2014
Sanborn Elementary School 51,560 1 1951 1995
South Elementary School 65,800 1 1957 1995
West Elementary School 94,000 1 1951
Woodhill Middle/ High Plain Elementary Schools 176,000 3 2002
Shawsheen Pre School 38,500 2 1923
The overall objective of the HVAC assessment was to conduct an independent survey of the
ventilation systems serving each school and determine if the systems were functioning properly
and are meeting or exceeding the current ASHRAE (American Society of Heating, Refrigerating,
Air Conditioning Engineers) Guidance for the Re-opening of Schools.
ASHRAE is a global professional society committed to serve humanity by advancing the art and
science of heating, ventilating, air conditioning, refrigeration and their allied fields. ASHRAE
developed a task force to help determine the technical approach to address the challenges of
the COVID-19 pandemic and possible future epidemics. A summary of the key general
recommendations related to HVAC systems is described below.
Inspection and Maintenance: Assess the condition of systems and make necessary
repairs.
Ventilation: A good supply of outside air, in accordance with ASHRAE Standard 62.1-
2019, to dilute indoor contaminants is a first line of defense against aerosol
transmission. Pre and post occupancy purge cycles are recommended to flush the
building with clean air.
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School HVAC Assessments September 28, 2020
Filtration: Use of at least MERV-13 rated filters is recommended if it does not adversely
impact system operation. If MERV-13 filters cannot be used, including when there is not
mechanical ventilation of a space, portable HEPA filters in occupied spaces may be
considered.
Air Cleaning: Air cleaners such as germicidal ultraviolet air disinfection devices may also
be considered to supplement ventilation and filtration. Technologies and specific
equipment should be evaluated to ensure they will effectively clean space air without
generating additional contaminants or negatively impacting space air distribution.
Energy Use Considerations: In selecting mitigation strategies, consideration should be
given to energy use as there may be multiple ways to achieve performance goals that
have greatly different energy use impact. Control changes and use of energy recovery to
limit or offset the effect of changes in indoor air ventilation rate and filter efficiency may
reduce or offset energy and operating cost penalties.
Project Goals and Objectives:
Based on a review of the ASHRAE recommended guidelines and collaboration with the Andover
Department of Facilities, an overall achievable scope of work to address the technical
challenges for this project was developed with the town and is summarized below.
Review of design documentation provided by the Town for each school including original
drawings, HVAC upgrade drawings, retro-commissioning reports and additional
applicable reports referencing the original design intent.
Review of preventative maintenance program including master schedules and process
flow of work orders and routine preventative maintenance activities.
Assessment of all of the major air handling units (AHUs) including roof tops units (RTUs)
providing ventilation air to the schools including but not limited to visual surveys for
cleanliness, functionality and control through the building automation system (BMS) and
review of the programmed sequences of operation impacting the supply of outside air to
the space.
Assessment of major ventilation equipment filter status and filter upgrades to MERV13
filtration.
Assessment of a percentage (to the extent possible) of the unit ventilators (UVs) serving
individual classrooms including but not limited to visual surveys for cleanliness,
functionality and controllability.
Collaboration with the Town’s Department of Facilities (Department) to review and
enhance the current building management’s programmed sequence of operations for
each school to enhance (to the extent possible) the quantity of outdoor air being
supplied to the space.
Assessment of programmed daily air flush pre and post occupancy and confirm
programmed occupancy schedules.
Assessment of the isolation rooms and dedicated airflow maintaining a negative space
pressurization.
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School HVAC Assessments September 28, 2020
Review of CO2 monitoring where applicable and programmed maximum ppm set points.
Review of the Department’s intended future upgrades to each school and future
recommendations.
Project Timeline:
NV5 was contacted by the Department of Facilities on August 13th and reviewed the general
scope or work required to perform the HVAC assessment of each school prior to the return of the
teachers and students. The following week of August 17th through August 21st, NV5 received
documents for each school for review prior to the onsite assessment. NV5 collaborated closely
with the entire Department of Facilities over the following three weeks to get access through-out
each school and perform the onsite HVAC assessment. Daily updates on findings were
distributed to the Department via field reports and spreadsheets and the Departments staff
addressed and fixed identified deficiencies around the clock during this time.
NV5 Firm Profile and Qualifications:
NV5 Global, Inc. (NASDAQ: NVEE) is a provider of professional and technical engineering and
consulting solutions to public and private sector clients in the infrastructure, energy,
construction, real estate and environmental markets. NV5 primarily focuses on five business
verticals: construction quality assurance, infrastructure, engineering and support services,
energy, program management, and environmental solutions. The Company has over 2,000
employees and operates out of 102 locations nationwide and abroad.
NV5 Global Inc. acquired Richard D Kimball, Inc. referred to as RDK Engineers on or about the
summer of 2016 and RDK became fully integrated into the NV5 brand in the summer of 2018.
RDK was founded locally in 1897 and is headquartered in the Town of Andover and continues to
provide HVAC, electrical, plumbing and fire protection, telecommunications, audio visual,
security, commissioning and energy consulting services. We have just under 200 multi-
disciplined engineers and administrative professionals locally here in Andover. Although our
name has changed, we will continue to provide our clients with the same level of service that we
have for the last 120 years with more extended service offerings. We have been working with
the Town of Andover closely on a multitude of HVAC projects over the past 20 years.
As a nationally recognized premier provider of commissioning and retro-commissioning services,
we have a portfolio of more than 2,000 projects including over 200 LEED projects including
numerous projects involving K-12 schools. Our team has held multiple contracts with the
Massachusetts School Building Authority (MSBA) for the past ten years as one of their preferred
commissioning engineers. In addition, we have been a preferred commissioning and retro-
commissioning provider for the Department of Capital Asset Management (DCAMM) for the past
ten years. Recent additional K-12 experience includes:
MSBA, Dracut Senior High School Addition/Renovation, Dracut, MA
Executive Summary
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School HVAC Assessments September 28, 2020
MSBA, New Marathon High School, Hopkinton, MA
MSBA, New Glover Elementary School, Marblehead, MA
MSBA, New Winchester High School, Winchester, MA
MSBA, New Marshall Simonds School, Burlington, MA
MSBA, Southeastern Regional Vocational Technical High School, South Easton, MA
MSBA, Cape Cod Regional Vocation Technical High School, Harwich, MA
MSBA, Marblehead Village Elementary School Renovation, Marblehead, MA
MSBA, Sutton Middle High School Renovation/Addition, Sutton, MA
MSBA, Stoneham Middle School Addition/Renovation, Stoneham, MA
The Winsor School, Center for the Performing Arts and Wellness, Boston, MA
Boston Prep Charter School, Boston, MA
North Andover New High School, North Andover, MA
Town of Andover Department of Facilities Staffing:
The Town of Andover Department of Facilities employs 4.5 full time skilled tradespersons to
maintain and repair HVAC systems and equipment at Town and School buildings. These consist
of 2.5 HVAC mechanics, a plumber, and a boiler mechanic. They are overseen by a Building
Operations Manager, who is also an HVAC Technician. All of the HVAC mechanics have received
Johnson Metasys BMS training. The Department also employs a full time mechanical engineer
who designs systems, diagnoses issues, and oversees mechanical design contracts.
The Administration of work orders and inventory is handled by a full time Work Control
Coordinator and a full time Materials Coordinator. Six of these individuals are trained in using
the Johnson Controls Metasys BMS system, with 3 of them having completed expert level
programming training. All of these individuals work under the Director and Deputy Director of
Facilities, who evaluate metrics and develop long term capital projects in collaboration with
staff, and who also use the BMS.
The Department of Facilities utilizes the SchoolDude computerized management and
maintenance system (CMMS). Several modules of this platform are used to support and track
repairs and maintenance. SchoolDude Preventative Maintenance module automatically
generates detailed equipment maintenance work orders based on a best practice schedule
defined by the operations and maintenance manuals for building systems. SchoolDude
Maintenance module is a work order system which assigns work by craft directly to
tradespersons for repairs as needed. SchoolDude inventory module records inventory purchases
and assignments to work orders to rack costs. SchoolDude Energy Manager tracks energy use
for every building.
The Town of Andover provided their Preventative Maintenance (PM) reports that they are
currently maintaining for each HVAC system for our review before and during the assessment.
Executive Summary
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School HVAC Assessments September 28, 2020
HVAC Assessment Methodology:
NV5 was provided with full transparent access to the Town’s documentation records for each
building and the Metasys building management system (BMS) to review the programmed
sequences of operations and programmed setpoints for each of the Rooftop Units (RTU’s), Air
Handling Units (AHU’s), Heating and Ventilating Units (HV’s) and Unit Ventilators (UV’s), AC units
and exhaust fans serving the various school spaces.
In collaboration with the Department of Facilities, NV5 prioritized the assessment of the air
handling equipment and respective filter installations. In addition to the visual observations of
the equipment, NV5 exercised the functionality and operation of each RTU, AHU, HV and UV by
changing the operating parameters through the Metasys BMS. For UV’s, an approximate
sampling of 25% was performed and similar findings for UVs were provided to the Department
of Facilities and they continued with the inspection of the remaining UVs based on our findings
and recommendations. Deficiencies observed by NV5 were immediately put into the repair
work order process and addressed by the facilities staff.
The Department of Facilities and NV5 developed a priority rating to assign to the deficiency
issues during the onsite assessment. The highest priority issues were determined to be any
element related to impacting the volume of outside air volume being supplied to the space.
Summary of Findings:
The Table below outlines the total number of ventilation units serving each school and the
number of high priority and low priority issues identified. High priority issues were determined
as having potential to impact the performance of the unit and the quantity of outdoor air being
supplied to the space.
All high priority (HP) items were coordinated and turned over immediately to the Department of
Facilities staff where they began processing immediately. The facilities staff proactively
addressed and repaired 100% of all high priority issues and each issue was reviewed
independently with our onsite team. All high priority items were addressed and repaired by the
facilities staff prior to return of teachers and students and the start of school on September 16,
2020.
The Department of Facilities continuously worked on the remaining low priority (LP) issues with
a large percentage of these issues being resolved. It should be noted that Shawsheen pre-
school opened at a later date. The total number of unit ventilators provided in the Table below
was provided by the town. NV5 assessed an approximate 25% sampling at each school as
appropriate. The issues remaining to complete are deemed low priority issues. Many of the low
priority issues are the result of older systems and aged equipment reaching the end of useful
life.
Executive Summary
Town of Andover Page 7 of 39
School HVAC Assessments September 28, 2020
Table 2 – Ventilation Equipment Summary
Building Name
Total
No.
AHUs
Total
No. of
RTUs
Total
No. UVs
Total
No.
of
Issues
High Priority
Issues
Addressed
and
Repaired
Low Priority
Issues
Remaining to
Complete
Andover High School 14 14 70 31 4 14
Doherty Middle School 5 2 53 61 5 55
West Middle School 4 3 45 14 4 4
Bancroft Elementary School 10 ----- ---- 14 10 4
Sanborn Elementary School 3 9 20 9 5 3
South Elementary School 2 10 30 28 15 6
West Elementary School 10 ---- 20 39 8 4
Woodhill Middle /
High Plain Elementary
Schools
12 2 ---- 20 8 12
Shawsheen Preschool 1 ---- 4 4 4 0
In Summary, the Department of Facilities meets and in many cases exceeds the guidelines
outlined in the ASHRAE guidance for the reopening of schools. All of the AHUs and RTUs were
surveyed to the extent possible and all necessary repairs related to the supply of outside air
were fixed by the Department. Pre and post occupancy purge cycles have been incorporated for
every school through the BMS and outside air intake has been increased to provide a good
supply of outside air in accordance with ASHRAE Standard 62.1. Filters have been upgraded to
MERV-13 rated filters for AHUs and RTUs to the extent possible. Demand control ventilation
(DCV) strategies and other control strategies have been modified so as not to adversely impact
the amount of outside air delivered to the space.
Acknowledgements:
On all of our projects, NV5 strives to be a strong “team” player. We work collaboratively with our
clients to establish goals that will meet the client’s needs throughout the project while
understanding that every project is diverse with its own set of unique circumstances and
requirements such as this pandemic related HVAC assessment. NV5 would like to acknowledge
the outstanding support and transparent collaboration that was received from the Department
of Facilities staff during the rigorous and intensive 3 week onsite effort. They proactively stayed
on top of every request from our onsite team and addressed each issue as it was brought to
their attention and notably worked around the clock to complete this effort.
Executive Summary
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School HVAC Assessments September 28, 2020
Table 3 – Abbreviations and Acronyms
Abbr. Description
AHU Air Handling Unit
ASHRAE American Society of Heating, Refrigerating and Air-Conditioning
BAS Building Automation System
BMS Building Management System
CM Construction Manager
CO2 Carbon Dioxide
Cx Commissioning
CxA Commissioning Authority
DCV Demand Control Ventilation
DOA Dedicated Outside Air
ERV Energy Recovery Ventilator
HEPA High Efficiency Particulate Air
HV Heating & Ventilating Unit
HVAC Heating, Ventilation, and Air Conditioning
IDIQ Indefinite Delivery, Indefinite Quantity
O&M Operations and Maintenance
OA Outside Air
PM Preventative Maintenance
PPM Parts Per Million
QC Quality Control
RTU Roof Top Unit
TAB Testing, Adjusting, and Balancing
UV Unit Ventilator
VRF Variable Refrigerant Flow
WC Water Column
HVAC Assessment Methodology
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School HVAC Assessments September 28, 2020
2.0 HVAC Assessment Methodology
HVAC Assessment Means and Methods:
NV5 was provided with full transparent access to the Town’s documentation for each school
including construction drawings, preventative maintenance plans and other pertinent reports.
Refer to Table below for a comprehensive list of documentation. NV5 was also granted access
to the Metasys BMS in order to review the programmed sequence of operations and setpoints
for each of the RTU’s, AHU’s, HV’s and UV’s serving the various school spaces.
NV5 and the Department of Facilities prioritized assessment of all major air handling equipment
to be assessed in lieu of a sampling methodology. The reasoning for this determination is
based on the circumstance that these units typically serve a multitude of spaces and have a
larger potential to cross contaminate. Assessment of filter installations and filter upgrades
were also prioritized and verified to be MERV-13 where applicable for these units. A sampling of
the UV’s of approximately 25% was determined to be adequate in identifying similar issues for
the Department of Facilities to assess and then subsequently verify on the remaining units. The
UVs are standalone pieces of equipment that serve individual spaces or classrooms with a
controlled quantity of outdoor air supplied to the space, hence, less potential for cross
contamination. NV5 provided the facilities staff with the testing protocols to assess the
remaining UVs.
In addition to the visual onsite assessment, NV5 reviewed the functional operation of each RTU,
AHU, HV and UV by modulating and adjusting the programmed operating parameters through
the Metasys BMS. The intent in doing so was to verity that outdoor air and return air dampers
and actuators were modulating and functioning adequately and that the percent opening of the
associated outdoor air damper was within the desired specifications. Control sensors and
devices were reviewed for reasonable and adequate monitoring and reporting. NV5 did not
perform calibration of unit sensors.
The Department of Facilities generated a repair work order for all of the NV5 identified issues
including both low and high priority issues. The work orders were prioritized with the highest
priority assigned to those elements that would provide increased outside air to the spaces
served by the associated equipment.
Table 4 – List of School Documentation
Type of Document School Drawings - 64-AHU Vol 2 M-1.4 thru 87-AHU Vol 2 M6.2 Andover High School
2013.08.16 Andover High School - RCx Report Andover High School
Facility Drawings - Levels 1-4 Andover High School
HVAC Assessment Methodology
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School HVAC Assessments September 28, 2020
Type of Document School CAD Construction Drawings - MEPFP Bancroft Elementary School
PDF Construction Drawings - MEPFP Bancroft Elementary School
Replace Main Office HVAC Project Equipment Scope Doherty Middle School
2018 Main Office AC - Plan of Sheetmetal Doherty Middle School
2019.05.03 Facilities Report FINAL Doherty Middle School
Split System Rev1 18952017_1347 Doherty Middle School
Drawings - 48 D-M1 thru 57 D-M10. Doherty Middle School
New offices - Mechanical 06.28.2017 Doherty Middle School
Facility Drawings - Levels B, 1, 2 Doherty Middle School
VRV Selection Report - Town of Andover School Phase 2 Doherty Middle School
2019.10.22 Sanborn, South & West MS - Study Report Revised Sanborn Elementary School
G-7113 - Andover Sanborn ES Café DCV 2019-04-11 Sanborn Elementary School
Drawings - 1998 HVAC 1 H1A thru HVAC 5 HVC Sanborn Elementary School
Library RTU - Trane Submittal Sanborn Elementary School
RTU 2015 New 1 Sanborn Elementary School
RTU 2015 New 2 Sanborn Elementary School
Drawings - 1961 023 HV1 thru 1961 025 HV3 Sanborn Elementary School
Facility Drawing Sanborn Elementary School
Cad Drawings - GER 0500 Heating Study Shawsheen Preschool
PDF Drawings - GER 0500 Heating Study Shawsheen Preschool
Cad Drawings - GER Heating Phase 1 Shawsheen Preschool
PDF Drawings - GER Heating Phase 1 Shawsheen Preschool
Cad Drawing - Steam to HW plan Shawsheen Preschool
PDF Drawing - Steam to HW plan Shawsheen Preschool
Cad Drawing - Fl Plans Combined Layout1 Shawsheen Preschool
PDF Drawing - Fl Plans Combined Layout1 (1) Shawsheen Preschool
Facility Drawings - Levels B, 1, 2 Shawsheen Preschool
2019.10.22 Sanborn, South & West MS - Study Report Revised South Elementary School
Drawings - As-Builts 54 H-1 thru 62 H-9 South Elementary School
Facility Drawing South Elementary School
PDF Drawings - Mechanical West Elementary School
Drawings - 1968 08 12 HV-1 thru HV-8 West Middle School
2013.03.22 HV System Upgrade West Middle School
2019.10.22 Sanborn, South & West MS - Study Report Revised West Middle School
Facility Drawings - Levels 1, 2 West Middle School
Drawings - 178 M0.1 thru 198 M5.3 Wood Hill Middle - High Plain Elementary
17062.00 Andover School AC Project - Bid Drawings - 02-14-2018 Wood Hill Middle - High Plain Elementary
Facilities Drawings - Levels Lower, Main, Upper Wood Hill Middle - High Plain Elementary
Table 5 – List of Preventative Maintenance Documentation
Type of Document School Preventative Maintenance Master Schedule Andover High School Collins Center
Preventative Maintenance Master Schedule Bancroft Elementary School
Preventative Maintenance Master Schedule Doherty Middle School
Preventative Maintenance Master Schedule High Plain Elementary School
Preventative Maintenance Master Schedule Sanborn Elementary School
Preventative Maintenance Master Schedule Shawsheen Preschool
Preventative Maintenance Master Schedule South Elementary School
Preventative Maintenance Master Schedule West Elementary School
Preventative Maintenance Master Schedule West Middle School
Preventative Maintenance Master Schedule Wood Hill Middle School
School Preventative Maintenance 07.01.19-07.19.20 HVAC All schools
School Preventative Maintenance HVAC All schools
HVAC Assessment Methodology
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School HVAC Assessments September 28, 2020
METASYS Building Management System (BMS):
The Town of Andover has chosen to utilize Johnson Controls Metasys Building Automation
System (BMS) for their building operations control. The BMS system is an intelligent
microprocessor based controller networks installed to monitor and control a buildings technical
HVAC systems and more. They allow the functionality of individual pieces of equipment to
operate as one integrated system. The entire system is made up of operator workstation, server
network, mircroprocessors, controllers, inputs and outputs to remotely monitor and control
locally mounted sensors and devices.
Typical System Components – Network
Web browser
Server
Workstation
Automation level controllers
Field level controllers
Operator terminals
Third party integrators
Room controllers
Programmed sequences of operations
Graphic displays
Alarms and notifications
Typical System Components – Field Devices
Airflow monitoring stations (CFM)
Temperature and humidity sensors
Damper actuators
Valve actuators
Airflow pressures
Water flow pressures
Carbon Dioxide sensors
Pumps, fans and motor status
Boiler and Chiller and Cooling tower status
Low level and high level connections
The Johnson Controls Metasys system is remotely monitored around the clock by the Andover
Department of Facilities trained staff. The BMS monitors and controls the day to day HVAC
operations of the school buildings and measures building performance. When building
parameters fall outside of their defined setpoints of performance, alarms and alerts are
HVAC Assessment Methodology
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School HVAC Assessments September 28, 2020
generated for the facilities staff to address. The facilities staff has the ability to adjust setpoints
when deemed feasible and practical.
NV5 collaborated with the facilities staff with programming changes to be implemented in an
effort to maximize the amount of fresh outdoor air being supplied to the space.
Below are examples of the BMS interface typical for each school.
Bancroft Elementary School – BMS Main Page
HVAC Assessment Methodology
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School HVAC Assessments September 28, 2020
Bancroft Elementary School – AHU-1
Bancroft Elementary School – HV-1
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
3.0 Facility Descriptions and Assessments
3.1 Andover High School
Existing HVAC System:
RTU’s serve the Field House, 3rd and 4th level Science classrooms, and the
Collins Center. AHU’ s serve the Kitchen, Lobby, Main Office, Health Office,
Library, Computer Labs, Lockers, Dunn Gym, Art Wing classrooms and Graphic
Arts classrooms. UV’s serve all perimeter classrooms (except for the Science
Labs), the Cafeteria, and 3rd level Teams room.
HVAC Assessment:
A total of 31 issues were identified at the Andover High School with 4 of these
issues determined to be high priority and the remaining deemed low priority.
100% of the high priority issues were addressed and repaired prior to teachers
and students returning to school on September 16, 2020. There are
approximately 14 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
Andover High School 14 14 70 31
RTU’s and AHU’s: Units have been provided with 2” MERV 13 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 75%
Outside Air (non-DCV) or 50% Outside Air (DCV). We identified various damper
positions that needed to be recalibrated.
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
Unit Ventilators: Units have been provided with 1” MERV 8 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 50%
Outside Air (DCV). Various damper positions need to be adjusted. Various CO2
sensors were reading unreliable in the Metasys system and need to be
recalibrated. Subsequently, the Department of Facilities performed functional
testing of all the remaining unit ventilators.
BMS:
Andover High School – AHU-2
Andover High School – UV - Room 375
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
3.2 Doherty Middle School
Existing HVAC System:
RTU’s serve the Auditorium and Faculty Dining. AHU’s serve the Lockers, Gym
and Music Rooms. UV’s serve the Library, Offices and all classrooms. Variable
Refrigerant Flow (VRF) with Energy Recovery Ventilator (ERV) systems serve the
Main Office and Student Services.
HVAC Assessment:
A total of 61 issues were identified at the Doherty Middle School with 5 of these
issues determined to be high priority and the remaining deemed low priority.
100% of the high priority issues were addressed and repaired prior to teachers
and students returning to school on September 16, 2020. There are
approximately 55 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
Doherty Middle School 5 2 53 61
Heating and Ventilating (HV) Units: Units have been provided with 2” MERV 13
filters, with the exception of HV-1, which has 2” MERV 8 filters. Filters for this unit
need to be upgraded. Outside air dampers were confirmed to be programmed for
a Minimum Position of 75% Outside Air (non-DCV) for HV-4 and HV-5. For HV-2
and HV-3 which serve the Gym, the dampers were found to be programmed to a
minimum of 25% outside air. The minimum damper positions for these units
should be increased to 75% outside air. For HV-6, when the mixed air dampers
were commanded 100% open, the mixed air dampers were closer to 40% open.
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
The damper linkage should be adjusted as necessary so that the mixed air
dampers modulate to the commanded position.
Unit Ventilators: Units have been provided with 1” MERV 8 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 50%
Outside Air (DCV). The CO2 reading for UV-121 was zero (0). This CO2 sensor
operation needs to be reviewed.
BMS:
Doherty Middle School – UV – Classroom 120
Facility Descriptions & Assessments
Town of Andover Page 18 of 39
School HVAC Assessments September 28, 2020
3.3 West Middle School
Existing HVAC System:
RTU’s serve the Library, Cafeteria, Kitchen and Lecture Hall. AHU’s serve the
Auditorium and Gym. UV’s serve all perimeter classrooms (except the Lecture
Hall), Weight Room, Locker Rooms, Main Office and Health Office.
HVAC Assessment:
A total of 14 issues were identified at the West Middle School with 4 of these
issues determined to be high priority and the remaining deemed low priority.
100% of the high priority issues were addressed and repaired prior to teachers
and students returning to school on September 16, 2020. There are
approximately 4 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
West Middle School 4 3 45 14
RTU’s and AHU’s: Units have been provided with 2” MERV 13 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 50%
Outside Air (DCV). Various AHU’s dampers were being commanded 0% open
during occupied mode. It is unclear why the mixed air damper command was
below the programmed minimum position of 50%. The units may have been
operating in a warm-up mode. If this is the case, the warm-up mode should be
disabled. The programming governing the control of the mixed air dampers
should be reviewed and revisions should be made to ensure that during occupied
mode, the mixed air damper command never drops below 50%. RTU-9 was
observed to be de-energized when commanded to occupied mode. The unit may
not have power. Outdoor air control could not be verified for this unit.
Facility Descriptions & Assessments
Town of Andover Page 19 of 39
School HVAC Assessments September 28, 2020
Unit Ventilators: Units have been provided with 1” MERV 8 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 50%
Outside Air (DCV). In general, the mixed air dampers were observed to modulate
to the commanded position. For UV-309, the filter was observed to be dirty and
should be replaced.
BMS:
West Middle School – UV – Classroom 101
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
3.4 Wood Hill Middle School
Existing HVAC System:
RTU’s serve the Dining area and Music/Fitness rooms. AHU’s serve the
remainder of the building.
HVAC Assessment:
A total of 20 issues were identified at the Wood Hill Middle School with 8 of
these issues determined to be high priority and the remaining deemed low
priority. 100% of the high priority issues were addressed and repaired prior to
teachers and students returning to school on September 16, 2020. There are
approximately 12 low priority issues remaining to complete that the Department
of facilities is actively addressing. It should be noted that total counts for Wood
Hill Middle School incorporate total counts for High Plain however the buildings
were assessed separately.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
Wood Hill Middle School 12 2 --- 20
AHU’s: AHU-1 has been provided with 2” MERV 13 Pre-filters, 4” MERV 13 HEPA
outside air filters and 2" MERV 13 return air filters. AHU-2 and AHU-3 have been
provided with 2” MERV 13 Pre-filters, 4” MEPA outside air filters and 2" MERV 13
return air filters. AHU-6 and AHU-7 have been provided with 2" MERV 13 and 12"
MERV 11 HEPA filters. AHU-1, AHU-2 and AHU-3 are 100% outside air units. For
AHU-6, the mixed air damper command was 25% with a CO2 reading of 2016
ppm. It does not appear that the unit is utilizing the CO2 reading, or the sensor
may be deficient, or thee unit may not be utilizing a CO2 sensor. It should be
confirmed if this unit is utilizing the DCV programming. If so, the AHU-6 minimum
mixed air damper command should be increased to 50%. For AHU-7, the mixed
air damper command was 100% with a CO2 reading of 504 ppm. It does not
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
appear that the unit is utilizing the CO2 reading. The dampers remain at 100%
open even with the outside air temperature above the economizer setpoint.
RTU’s: Units have been provided with 2” MERV 13 and 12” MERV 11 HEPA filters.
The minimum mixed air damper commands are programmed to 50%. It is
unclear if the RTU’s are utilizing the CO2 readings. For RTU-1, one of the outside
air dampers remained closed at all times regardless of the damper position
command.
BMS:
Wood Hill Middle School – AHU-1
Facility Descriptions & Assessments
Town of Andover Page 22 of 39
School HVAC Assessments September 28, 2020
3.5 Bancroft Elementary School
Existing HVAC System:
AHU’s serve the entire building.
HVAC Assessment:
A total of 14 issues were identified at the Bancroft Elementary School with 10 of
these issues determined to be high priority and the remaining deemed low
priority. 100% of the high priority issues were addressed and repaired prior to
teachers and students returning to school on September 16, 2020. There are
approximately 4 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
Bancroft Elementary
School 10 ----- ---- 14
AHU’s: Exceptions to the filter change out were noted as follows: AHU-3 was
noted to have 2" MERV 8 installed in the pre-filter rack and final filter rack. AHU-
5 was noted to have 2" MERV 8 filters installed in the return air filler rack, pre-
filter rack and final filter rack. AHU-6 was noted to have 2" MERV 8 filters. The
installed MERV 8 filters in these AHU systems should be replaced with MERV 13
filters.
For AHU-1 through AHU-8, the demand control ventilation programming had not
yet been updated. The programming should be updated to reset the mixed air
damper command from 50% to 100% as the return air CO2 rises from 600 ppm
to 800 ppm. The majority of units were observed to utilize CO2 setpoints of 800
ppm and 1000 ppm and a minimum mixed air damper command below 50%.
HV Units: Exceptions to the filter change out were noted as follows: HV-2 was
noted to have 2" MERV 8 filters. The installed MERV 8 filters should be replaced
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
with MERV 13 filters. For the HV Units, the demand control ventilation
programming had not yet been updated. The programming should be updated to
reset the mixed air damper command from 50% to 100% as the return air CO2
rises from 600 ppm to 800 ppm. The majority of units were observed to utilize
CO2 setpoints of 800 ppm and 1000 ppm and a minimum mixed air damper
command below 50%.
BMS:
Bancroft Elementary School – BMS Main Page
Facility Descriptions & Assessments
Town of Andover Page 24 of 39
School HVAC Assessments September 28, 2020
Bancroft Elementary School – AHU-1
Bancroft Elementary School – HV-1
Facility Descriptions & Assessments
Town of Andover Page 25 of 39
School HVAC Assessments September 28, 2020
3.6 High Plain Elementary School
Existing HVAC System:
RTU’s serve the Dining area and Music/Fitness rooms. AHU’s serve the
remainder of the building.
HVAC Assessment:
A total of 20 issues were identified at the High Plain Elementary School with 8 of
these issues determined to be high priority and the remaining deemed low
priority. 100% of the high priority issues were addressed and repaired prior to
teachers and students returning to school on September 16, 2020. There are
approximately 12 low priority issues remaining to complete that the Department
of facilities is actively addressing. It should be noted that total counts for Wood
Hill Middle School incorporate total counts for High Plain however the buildings
were assessed separately.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
High Plain Elementary 12 2 --- 20
AHU’s: AHU-8 has been provided with 2” MERV 8 and 12” MERV 11 HEPA filters.
AHU-4 and AHU-5 have been provided with 2" MERV 13 and 4" MEPA outside air
filters, and 2" MERV 13 return air filters. AHU-4 and AHU-5 are 100% outside air
units. AHU-8 was not operating due to its associated return fan VFD being offline
in alarm. AHU-8 appears to have a minimum mixed air damper command of
10%. The AHU-8 DCV programming appears to require updating.
HV Units: Units have been provided with 2” MERV 8 Pre-Filters and 12” MERV 11
HEPA filters. For HV-1, the mixed air damper command was 50% with a CO2
reading of 986 ppm. It does not appear that the unit is utilizing the CO2 reading.
For HV-2, the mixed air damper command was 25% with a CO2 reading of 703
ppm. It does not appear that the unit is utilizing the CO2 reading. It should be
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
confirmed if these units are utilizing the DCV programming. If so, the HV-2
minimum mixed air damper command should be increased to 50%.
BMS:
High Plain Elementary School – AHU-4
Facility Descriptions & Assessments
Town of Andover Page 27 of 39
School HVAC Assessments September 28, 2020
3.7 Sanborn Elementary School
Existing HVAC System:
RTU’s serve the Main Office, Special Education offices, Library, Computer Room,
Music Room, Resource Rooms and all interior offices. AHU’s serve the
Cafetorium and Gym. UV’s serve all three wings of classrooms.
HVAC Assessment:
A total of 9 issues were identified at the Sanborn Elementary School with 5 of
these issues determined to be high priority and the remaining deemed low
priority. 100% of the high priority issues were addressed and repaired prior to
teachers and students returning to school on September 16, 2020. There are
approximately 3 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
Sanborn Elementary 3 9 20 9
RTU’s and AHU’s: Units have been provided with 2” MERV 13 filters with the
exception of AHU-5. AHU-5 was observed to be equipped with a mix of MERV 8
and MERV 13 filters. All MERV 8 filters should be replaced with MERV 13 filters.
For AHU-5, the outdoor air damper and return air damper do not appear to
modulate. The return air damper remains approximately 100% open and the
outdoor air damper remains approximately 50% open. There may be a
pneumatic leak at this unit. For Cafe Unit 1 and Cafe Unit 2, the return air
dampers does not appear to rotate. The linkages may be disconnected. Damper
operations should be reviewed and necessary actions taken to ensure that the
damper modulates to the commanded position. For RTU-1(A), RTU-1(B) (two
units are labeled RTU-1 on the roof), RTU-2, AHU-4, RTU-6 and RTU-7, the damper
commands are not available through Metasys. The mixed air dampers are
Facility Descriptions & Assessments
Town of Andover Page 28 of 39
School HVAC Assessments September 28, 2020
positioned for approximately 20% outdoor air. Minimum mixed air damper
commands should be increased to 75%. This may need to be programmed at the
unit’s packaged controller.
Unit Ventilators: Units have been provided with 1” MERV 8 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 50%
Outside Air (DCV). No deficiencies were noted for the Unit Ventilators that were
assessed.
BMS:
Sanborn Elementary School – AHU – Gymnasium
Sanborn Elementary School – UV – Classroom A1
Facility Descriptions & Assessments
Town of Andover Page 29 of 39
School HVAC Assessments September 28, 2020
3.8 South Elementary
Existing HVAC System:
RTU’s serve the Main office, Kitchen, Music, Chorus, Art, Interior Special
Education rooms and the Gymnasium. AHU’s serve the Cafetorium. UV’s serve all
perimeter classrooms, Nurse and Teacher’s Lounge.
HVAC Assessment:
A total of 28 issues were identified at the South Elementary School with 15 of
these issues determined to be high priority and the remaining deemed low
priority. 100% of the high priority issues were addressed and repaired prior to
teachers and students returning to school on September 16, 2020. There are
approximately 6 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
South Elementary 2 10 30 28
RTU’s: The majority of the units have been provided with 1” MERV 8 filters. The
packaged RTU’s may not have the capacity to handle the static pressure drop of
a 1” MERV 13 filter. This should be confirmed with the unit manufacturer. The
damper commands are not available through Metasys. The mixed air dampers
are positioned for approximately 20% outdoor air. Minimum mixed air damper
commands should be increased to 75%. This may need to be programmed at the
unit’s packaged controller.
HV Units (Cafetorium and Gymnasium): Units have been provided with 2” MERV
13 filters. The demand control ventilation programming needs to be updated to
reset the minimum mixed air damper command from 50% to 100% as the space
CO2 level rises from 600 ppm to 800 ppm. For HV-1, the mixed air dampers
appeared to remain in their recirculation positions (100% return air) during
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
occupied mode. Damper operation should be reviewed and corrections made to
ensure the dampers modulate to the commanded position. For HV-2, the mixed
air dampers are unable to modulate 100% open. The dampers appear to stop
modulating once they are approximately 75% open.
Unit Ventilators: Units have been provided with 1” MERV 8 filters. Outside air
dampers were confirmed to be programmed for a Minimum Position of 50%
Outside Air (DCV). Various CO2 sensors were reading Unreliable in the Metasys
system and need to be recalibrated. For UV-101, the pneumatic line appears to
be disconnected from damper actuator. The dampers did not modulate when
commanded. For UV-121, the return air damper does not move and stays in full
open position. The damper and linkage appear to require adjustment.
BMS:
South Elementary School – RTU – Rooms 142 & 144
South Elementary School – UV – Classroom 103
Facility Descriptions & Assessments
Town of Andover Page 31 of 39
School HVAC Assessments September 28, 2020
3.9 West Elementary School
Existing HVAC System:
AHU’s serve A Pod and B Pod Classrooms, Library, Classrooms between the Main
Office and the Library, both Gyms and the Auditorium. UV’s serve the Main Office,
Cafeteria, Kitchen, Kindergarten, Grade 1a and Grade 5 Classrooms.
HVAC Assessment:
A total of 39 issues were identified at the West Elementary School with 8 of
these issues determined to be high priority and the remaining deemed low
priority. 100% of the high priority issues were addressed and repaired prior to
teachers and students returning to school on September 16, 2020. There are
approximately 4 low priority issues remaining to complete that the Department
of facilities is actively addressing.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
West Elementary 10 ---- 20 39
AHU’s: The four AHU’s in the basement have 2” MERV 13 filters. The Auditorium
AHU has 2” MERV 8 filters. It should be confirmed if the Auditorium AHU can be
upgraded to MERV 13 filters. For AHU-C, the three dampers (outside air, return
air and exhaust air) do not fully open when commanded to 100%. Damper
linkage may require some adjustment. For AHU-D, the return air damper did not
appear to modulate. It remained fully open with the outside air damper
commanded to 100% open. For AHU-E, the return air damper and exhaust air
damper range of modulation appears to be limited. For the Auditorium Unit, the
mixed air dampers only opened to approximately 20% position when
commanded to the 100% position.
HV Units: For the three HV units serving the two Gymnasiums, filter types were
not observed due to the high elevations of the HV unit installations. When the
Facility Descriptions & Assessments
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School HVAC Assessments September 28, 2020
dampers positions were commanded to 100% and 0%, the actuator pistons were
observed to stroke, but the actual damper positions were not visually verified.
Unit Ventilators: Units have been provided with 1” MERV 8 filters. The majority of
filters were dirty. NV5 was informed that these filters are scheduled to be
replaced within the next week. The filters in the four unit ventilators serving the
Cafeteria do not have MERV ratings. These four units have multiple filters in
them and they do not appear to be the correct size for the units. Outside air
dampers were confirmed to be programmed for a Minimum Position of 75%
Outside Air (non-DCV). For a number of the unit ventilators, the dampers did not
appear to modulate, or had minimal modulation. It was noted that the linkage
for many of these dampers were not functional, corroded and impeded by debris.
The dampers and linkage are dirty.
BMS:
West Elementary School – AHU-1
Facility Descriptions & Assessments
Town of Andover Page 33 of 39
School HVAC Assessments September 28, 2020
West Elementary School – UV – Room D1
Facility Descriptions & Assessments
Town of Andover Page 34 of 39
School HVAC Assessments September 28, 2020
3.10 Shawsheen Preschool
Existing HVAC System:
A Dedicated Outside Air (DOA) system serves the whole building. UV’s serve the
classrooms in the West Wing.
HVAC Assessment:
A total of 4 issues were identified at the Shawsheen Preschool with all 4 of these
issues determined to be high priority. 100% of the high priority issues were
addressed and repaired prior to teachers and students returning to school.
Building Name Total No.
AHUs
Total No.
RTUs
Total No.
UVs
Total No.
of Issues
Shawsheen Preschool 1 ---- 4 4
Unit Ventilators: The four unit ventilators have been provided with 1” MERV 8
filters. The dampers did not appear to be fully functional. When the dampers
were commanded to modulate, the return air damper did not change position.
The outdoor air damper could not be observed because it is located behind the
return air damper blade. The damper linkages appear to be in poor condition and
require maintenance/repair. Damper operation should be reviewed by the
facilities group at each unit.
When the unit ventilators were in occupied mode, the mixed air dampers were
being commanded to 0% open. Since the units do not have a return air CO2
sensor, the minimum mixed air damper command should be 75% open during
occupied mode.
For UV-1 serving Classroom 3/3a, the supply fan remained off when it was being
commanded to run. The fan operation should be reviewed by the facilities group.
Facility Descriptions & Assessments
Town of Andover Page 35 of 39
School HVAC Assessments September 28, 2020
BMS:
Shawsheen Preschool – Fresh Air Makeup Unit
Shawsheen Preschool – UV-3 – Classroom 9 & 9A
General Observations
Town of Andover Page 36 of 39
School HVAC Assessments September 28, 2020
4.0 General Observations
HVAC System Air Filters:
The schools’ HVAC systems with existing 2” filters were to be provided with new MERV 13 filters.
This includes the Rooftop Units, Air Handling Units and HV Units serving the buildings.
The schools’ HVAC systems with existing 1” filters were to be provided with new MERV 8 filters.
This includes the Unit Ventilators serving the classroom spaces.
Filter types were verified by NV5 as the system operations were reviewed. Based on the Town’s
Preventative Maintenance records, the majority of filters were changed in February and March
of 2020. The Town has noted that all filters have been replaced by the end of August 2020. As
noted by the Town, 95% of the school HVAC equipment with 2” filters have been provided with
MERV 13 filters. Any remaining filter replacements are currently due to filter orders being
backlogged at the manufacturing sites. The Town of Andover does have the required filters on
order.
Any systems that had dirty filters were noted by NV5 and the Department of Facilities
department has changed those filters prior to the start of school. The Town will also be changing
filters based upon the upcoming Preventative Maintenance schedules. The Town’s preventative
maintenance schedule has the filters being changed every three months throughout the school
year.
Demand Control Ventilation (DCV) Systems:
The schools utilize Johnson Controls Metasys for the Building Management System (BMS) for
each of the schools.
For any systems that are not programmed with DCV controls, the minimum mixed air damper
position is to be set to 75% open (75% outside air, 25% return air).
For any systems that are programmed with DCV controls, the minimum damper position is to be
set to 50% open. As the CO2 level increases from 600 ppm to 800 ppm, the damper position is
to increase from 50% to 100% (100% outside air, 0% return air).
The Department of Facilities department has noted that the CO2 sensors are calibrated
periodically utilizing a calibration kit or a calibrated sensor.
Occupancy Schedules:
Pre and post occupancy purge cycles to flush the building with clean air were implemented and
the occupancy schedules for the schools has been revised to two hours prior to the maintenance
staff arriving on site at 6:00 a.m., until two hours after the maintenance staff has left the site at
General Observations
Town of Andover Page 37 of 39
School HVAC Assessments September 28, 2020
11:00 p.m. Consequently, the HVAC systems will be operating from 4:00 a.m. until 1:00 a.m.,
and will be off from 1:00 a.m. until 4:00 a.m., Monday through Saturday. This programming has
been done in the Town’s Metasys building management system (BMS). The Town has noted
that Wednesday’s and Saturday’s will be cleaning days for the schools.
Negative Pressure Isolation Rooms:
The Town of Andover has established an isolation room in each school to house any student or
faculty that is not feeling well and has been assessed by the school nurse to remain in isolation
from the school population. Each isolation room has been equipped with a manometer on the
outside of the room to display the room’s air pressure in relation to the adjacent spaces. The
isolation rooms were targeted to have a pressure of -0.01 inches of water column (-0.01“w.c.) in
relation to the adjacent spaces. With the space being negative, this indicates that air is flowing
from the adjacent spaces into the isolation room, with the door closed. The majority of the
isolation rooms have been provided with signage to indicate restricted access to the space. The
majority of the isolation rooms have a second means of egress to allow the isolated person to
exit the space through another means of access to the exterior of the building.
Future Planned Projects
Town of Andover Page 38 of 39
School HVAC Assessments September 28, 2020
5.0 Recommendations and Next Steps
In Summary, the Department of Facilities meets and in many cases exceeds the guidelines
outlined in the ASHRAE guidance for the reopening of schools. All of the major AHUs and RTUs
were assessed and all noted deficiencies are recorded and tracked in the Departments work
order system. The Department of Facilities has indicated that all high priority items, relating to
operation, outside air damper setpoints and BMS communications, have been corrected as of
Wednesday, September 16, 2020.
Lower priority items such as filter change-outs (MERV 8 changed to MERV 13) will be addressed
once backlogged filter orders are received. CO2 sensor calibrations will be also performed as
required. The CO2 sensor corrections are lower priority as the typical outside air volume
delivered by the HVAC systems has already been increased based on the revised Metasys
programming.
Pre and post occupancy purge cycles have been incorporated for every school through the BMS
and outside air intake has been increased to provide a good supply of outside air in accordance
with ASHRAE Standard 62.1. Demand control ventilation (DVC) strategies and other control
strategies have been modified so as not to adversely impact the amount of outside air delivered
to the space.
Department of Facilities Planned Upgrades:
The Department of Facilities noted that they have started the process of cleaning the exhaust
grilles throughout the schools’ spaces. Facilities personnel also noted that they are in the
process of creating an annual preventative maintenance program for inspecting and cleaning
the exhaust systems serving the schools. This process will create better conditions for the space
airflows to be maintained as designed and will allow the exhaust equipment to operate under
the intended conditions.
The Department of Facilities noted that they have employed additional staff that are targeted to
perform HVAC system filter replacements as scheduled through the PM work order schedule.
This staff is also targeted to receive training on the Metasys controls system so that they can
functionally test the HVAC systems and review their operation on a regularly scheduled basis.
Additionally, they have created an automatically generated PM for each school to inspect and
clean every exhaust grill in every school.
The Department of Facilities noted that they have just obtained funding at the 2020 town
meeting to create a system-wide inventory of the town and schools’ mechanical systems to
create a 20 year replacement plan.
South Elementary School has begun design phase services for replacement of all new HVAC
equipment serving all spaces.
Future Planned Projects
Town of Andover Page 39 of 39
School HVAC Assessments September 28, 2020
Recommendations for Improving HVAC System Performance:
It is recommended that the facilities group review the damper operations of each of the HVAC
systems during the filter change that proceeds the start of the school year. With this, any
damper operation deficiencies can be addressed prior to the school year.
Throughout the school year, it is recommended that the facilities group reviews the Metasys
BMS system periodically, to confirm that any overrides, communication drops or any other items
can be addressed and set back to their normal operating parameters.
As a majority of the schools have Unit Ventilator systems serving the classrooms, it is
recommended that the custodial staff avoid sweeping the floors towards the bottom of the units
as this is where the return air from the space is drawn in. This would help to avoid any paper
trash or dust from being drawn in to the unit ventilators and reducing the effectiveness of the
filters. Outside air inlets should also be cleaned on a regular basis as the intakes have the
tendency to accumulate leaves, grass and other debris from the exterior of the building.
It is recommended that the HVAC systems be retro-commissioned so that their full operation
can be reviewed and any deficiencies can be addressed to keep the systems operating in the
manner they were designed to operate. Refer to the next section for additional retro-
commissioning information.
Retro-Commissioning:
Retro-commissioning is the application of the commissioning process to existing buildings.
Retro-commissioning is a process that seeks to improve how building equipment and systems
function together. Depending on the age of the building, retro-commissioning can often address
problems that have developed throughout the building's life. In all, retro-commissioning
improves a building's operations and maintenance (O&M) procedures to enhance overall
building performance, increase occupant comfort and save energy. It is recommended that a
building’s HVAC systems be retro-commissioned every three to five years. It is estimated that
retro-commissioning services would cost an estimated $25,000 to $30,000 per school.
In addition to retro-commissioning, it is recommended that a certified Testing, Adjusting and
Balancing (TAB) firm take air flow and water flow readings on the HVAC systems to evaluate if
they are operating as originally designed. The TAB firm could then make any possible
adjustments to the HVAC systems so that they are operating as close as possible to their
original design.