Installation of a GREE FreeMatch R32 GWHD(24)ND6MO 2-head wall-mounted heat pump in Saint-Hugues

Cooling an institutional space without touching the suspended ceiling or fire alarm devices

At Saint-Hugues, in the Maskoutains RCM, we installed a GREE FreeMatch R32 wall-mounted heat pump with two heads in a building for light institutional use: suspended ceiling with acoustic tiles, structural drop around the perimeter, manual alarm station, and portable fire extinguisher visibly marked within the immediate field of view of the installation area.

This type of project is not planned like a house. At AirGreen, we regularly handle buildings in this category in Montréal, Laval, Longueuil, and Montérégie, and experience has taught us that the challenges of a commercial installation are almost never related to refrigeration. They are regulatory, logistical, and aesthetic.

The system: GREE FreeMatch R32, GWHD(24)ND6MO compressor

Technical data

R32 is an A2L refrigerant: what this means in an occupied building

This is the most misunderstood aspect of the entire transition to R32, and it is the one that matters most in a space open to the public.

R32 is classified as A2L: low toxicity, slightly flammable. It does not ignite under normal operating conditions—it requires a high concentration in an enclosed space and a clear ignition source. However, the classification imposes a design approach that R410A did not require: the refrigerant charge must be considered in relation to the volume of the served room.

In practical terms, the smaller the room, the lower the permissible charge on a given head. An oversized head in a cramped room is not merely a poor comfort choice—it is a calculation that must be redone.

The FreeMatch R32 comes with an integrated A2L leak detection sensor. This sensor is not a decorative accessory: if a leak is detected, the unit's control logic responds accordingly. We check its operation during commissioning and record it in the report provided to the building manager.

What we did in Saint-Hugues before drilling:

1. Measured the volume of each served zone (actual area × height below the suspended ceiling, not slab height).
2. Distributed the load between the two heads based on these volumes rather than on the catalog.
3. Documented the calculation in the file, available to the insurer and any inspector.

A contractor who installs R32 in a commercial building without performing this calculation puts the client at risk. We do not.

The constraints specific to this room, and our decisions

The suspended ceiling and the perimeter drop

The site photo shows the exact difficulty: an acoustic tile ceiling with a perimeter drop at the wall corner. The usable installation height is therefore reduced, and the head must be positioned beneath the drop without suffocating its upper intake grille.

We anchored the mounting plate to the wall structure—never to the suspended grid, and never to a finish panel alone. A wall-mounted head of this size, with its condensate pan full, requires structural anchoring. Every year, we take over installations where the plate was screwed into bare drywall.

The proximity of the manual fire alarm call point and the fire extinguisher

On the same wall, there is a manual fire alarm call point and, immediately beside the door, a portable fire extinguisher with its signage. These elements impose rules that we systematically apply in commercial installations:

• No obstructed egress. The manual call point must remain accessible and visible from the circulation corridor. Neither the head, its conduit, nor its wiring may obscure it.
• Fire extinguisher signage must remain within the visual axis. A sign moved “because it was in the way” is a non-compliance.
• Blown air must not sweep across a smoke detector. A direct air stream onto a spot-type detector can delay its response or, conversely, trigger nuisance alarms by stirring up dust. We check the louver orientation based on the actual position of the detectors, not their theoretical position on the plan.

These are ten-minute checks that prevent a complete redo after an inspection by the fire department.

Routing through surface-mounted rather than concealed raceway

In a finished, occupied building, opening a wall means dust, cutting, repair, painting, and several days of downtime. Instead, we routed the connection through surface-mounted raceway painted to match the wall, with a straight vertical drop and a short pass-through to the exterior, directly through the masonry wall.

This choice is deliberate, and we stand by it:

• The refrigerant line run is short, so pressure losses are minimal and the additional refrigerant charge remains low, or even zero below the 30 m precharged limit.
• Future service access is immediate. A connection concealed in a wall is a connection that cannot be inspected.
• The work can be completed in a single day, with no additional trade required.

The only real criterion is the quality of execution: level raceway, straight routing, clean bends, a wall sleeve with an outward slope, and sealing with the appropriate firestop when the wall is fire-rated.

Leaving the protective film in place

In the photo, the head is still covered with its factory plastic film. This is not an oversight — it is our protocol. The film remains in place until the work is complete and is removed only during commissioning, in front of the client. In an occupied building, drilling dust, paint splatter, and furniture handling can damage a new casing within hours.

Common mistakes in light commercial installations

We regularly perform corrective work on projects of this type in Saint-Hyacinthe, on the South Shore and the North Shore. The same defects keep recurring:

• No load calculation by zone. The space is treated as a single volume even though two heads serve two distinct thermal environments with different internal gains (occupancy, lighting, equipment).
• Electrical power tapped from an existing circuit. The GWHD(24) requires a dedicated circuit protected at 25 A with an accessible disconnect. Connecting it to a lighting or receptacle circuit is a mistake, not a shortcut.
• Condensate discharged into a floor drain without an adequate trap. In commercial settings, returning odors are a daily source of complaints.
• No documentation provided to the property manager. A commercial building changes managers. The AHRI sheet, evacuation report, final charge, and HVAC maintenance schedule must be left in the building's records, not just in one person's email inbox.
• Filters never cleaned. A commercial space clogs its filters three to four times faster than a residence. The maintenance schedule must account for this; otherwise, the SEER2 of 21 is just a number on paper.

Efficiency and eligibility for incentive programs

The GWHD(24)ND6MO delivers a SEER2 of 21, an HSPF2 of 10, and the ENERGY STAR Cold Climate designation, with heating capacity maintained down to -30 °C—covering Montérégie's actual extremes without systematically relying on electric backup heat.

For a small electrically heated building, replacing resistance heating with a heat pump of this efficiency (COP of 3.9 under nominal conditions) significantly changes the winter consumption curve, especially during the shoulder seasons, when the inverter modulates below one-third of its capacity.

In terms of financial incentives, the equipment falls within the performance categories generally recognized by energy-efficiency programs offered in Quebec, including programs for commercial and institutional buildings. Eligibility criteria, maximum amounts, and required documents vary by program and year: we validate each application when the quote is prepared and provide the AHRI numbers, technical data sheet, and proof of installation required for processing.

Why the commercial context changes everything

A successful residential HVAC installation keeps a family comfortable. A successful commercial installation must also withstand intensive use, survive a change of manager, pass a fire inspection, never obstruct an evacuation route, and be serviceable without dismantling a ceiling.

That is why we document every project, why we calculate the A2L charge based on room volume, and why we prefer a clean, accessible line set cover to an invisible but impossible-to-service recessed installation.

AirGreen performs the load calculation, supplies the equipment, carries out the complete HVAC installation, connects the dedicated electrical circuit, provides documented commissioning, and offers contractual HVAC maintenance for your wall-mounted heat pump, in both residential and light commercial settings, in Montreal, Laval, Longueuil, on the North Shore, the South Shore, and in Montérégie, including Saint-Hugues and the Saint-Hyacinthe area.

Contact our team for an assessment of your building.