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North Building Exterior.02.jpg

Air Conditioning &

Improved Occupant


Improved IAQ &

Introduction of

Fresh Air System

LED Lighting &


Color Temperature

Touchless, Water


Plumbing Fixtures

Following completion of the Sustainability and Indoor Air Quality (IAQ) Project, MHR was hired to implement a mechanical fresh air system and enhance IAQ of the school's North Building.

Existing Conditions

The North Building (built in 1986) was previously only ventilated by a central exhaust fan in conjunction with operable windows.  While this was acceptable at the time, this is not currently code compliant and similar systems in school buildings has led to indoor air quality (IAQ) issues as the induced outdoor air is not filtered and conditioned and during unfavorable outdoor air ambient conditions the use of operable windows is limited.  The building was heated by a gas-fired condensing boil connected to a hydronic (fin-tube) hot water heating system

The building did not have any controllable filtered fresh air induction, no humidity control, no air conditioning, and it was not integrated into the campus wide building management system (BMS) system.


The North Building Air Conditioning and IAQ upgrade involved conditioning the building’s upper and lower hallways, all classrooms, and the Twitchell Room (multipurpose room).  Advanced air handling equipment included dedicated outdoor air system (DOAS) and variable refrigerant flow (VRF), was located within an expanded exterior enclosure.  Fresh air ductwork and refrigeration line sets laminated to the exterior of the building were encased in an architectural enclosure.  The project received a utility incentive of $5,161

The ventilation and air conditioning system were designed and installed in accordance with the 2018 Connecticut State Building and Fire Safety and Fire Prevention Codes including the 2015 version of the International Mechanical Code and International Energy Conservation Code, and associated Connecticut amendments.

Project Scope: HVAC

The enhanced ventilation system consists of a 2,000 cfm 100% outdoor air DOAS unit, which provides conditioned fresh air to the classrooms, hallways, and the Twitchell Room through a new ducted air distribution system.  The new outdoor air system provides neutral temperature air (approximately 72 ºF) and dehumidified air when the building is occupied.  The outdoor air enters the classrooms directly through side wall supply registers.  The new DOAS outdoor air unit is located in the expanded existing enclosure

The new air conditioning system consists of wall-mounted ductless heat pump type VRF fan coil units in the classrooms and the Twitchell Room; each classroom has one 2-ton unit, and the Twitchell Room is serviced by three 2-ton units.  The upper and lower hallways each consist of a single ceiling-mounted cassette unit.  The VRF heat pump units are connected to refrigerant piping to an 18-ton pad-mounted condensing unit, which is located within the new outdoor enclosure

The system offers advanced indoor air quality (IAQ) by providing enhanced filtered and dehumidified fresh air via MERV-13 filtration and in-room bipolar ionization to eliminate airborne viruses, reduce particulate matter, dust, and pollen.  This also enhances filter performance without impeding air circulation

Installation of needlepoint bipolar ionization units in each air air handler to improve air filtration and enhance IAQ and occupant comfort

Installed networked building management system (BMS) controls (FX-80) to integrate with campus wide BMS platform.

Project Scope: Hydropower Water Fixtures

The school installed foot pedal operated sinks and upgraded existing lavatory fixtures in all bathrooms (faucets and toilet and urinal flushometers) to self-generating hydropower, water saving, touchless fixtures.

Project Scope: Interior Restoration

In addition to providing conditioned fresh air, this project also included restoration of the interior of the walls, ceilings, stairs, raisers, railings, doors and wood surfaces of the building.

Painting: Patched holes and repainted the walls of all classrooms, multi-purpose room, hallways, vestibules, bathrooms, and stairwell / atrium.  Sanded and painted hollow metal door frames / jams of classrooms and entrance and vestibule doors.

Woodwork: Cleaned, deglossed, and refinished all wood doors, benches and windows in multi-purpose room, and hallway cabinets.

Hallway Ceilings: Removed and replaced ceiling tiles and grid of the hallways and vestibules to allow for symmetric positioning of HVAC equipment and lighting.

Lighting: Replaced off-colored lights directly outside of classrooms to maintain a homogenous color appropriate for a school environment.

Building Safety Measures: New ductwork included fire safety dampers and installation of fire barrier sheetrock above drop ceiling.

Project Scope: Exterior Enclosure

The architecturally designed, cedar enclosure was extended parallel to the northern side of the facility.  The enclosure has cedar walls with copper capping accent to harmonize the period details of the school building.

The vertical enclosure houses the linesets and power supply and was designed to match the ground enclosure.  The horizontal banding of the vertical enclosure was constructed to line up with and complement the building’s dark brick banding.






Interior Restoration
Water Fixtures
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