An HVAC project designed for Montreal winters, discreet from the street and robust on the roof
At AirGreen , we support every homeowner in Greater Montreal with HVAC solutions tailored to the building's real-world context. In this Côte-des-Neiges–Notre-Dame-de-Grâce duplex, the goal is clear: to provide reliable heating and efficient air conditioning to multiple rooms, without cluttering the facade or balcony. The answer? A Gree FreeMatch R-32 MultiZone heat pump installed on a flat roof , elevated above the snow level, silent and virtually invisible from the street.
Why choose a Gree R-32 MultiZone on the roof?
For this type of Montreal plex, several factors guide the design:
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Multi-room distribution : two or three indoor wall-mounted heads powered by a single MultiZone condenser. Balanced comfort is achieved between the living room, bedrooms and hallway, without multiple outdoor units.
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Installation on a flat roof : free from any ground constraints, no visual impact on the facade, better security against vandalism and acoustic clearance for the neighborhood.
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R-32 Technology : Next-generation refrigerant that reduces GWP compared to R-410A, for higher seasonal efficiency and simplified maintenance.
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Extreme cold performance : Gree's FreeMatch R-32 range maintains useful capacity down to approximately −25°C , meeting the winter needs of Montreal, Laval, Longueuil, North Shore and South Shore .
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Program Eligibility : Depending on the configuration chosen (power, Energy Star efficiency), the project may open the door to local subsidies . Our team guides the process, with supporting evidence.
Design and implementation: a perfectly integrated rooftop HVAC system
Support: stability, longevity and respect for the membrane
We place the outdoor unit on a steel trestle attached to treated wooden skids resting on high-density foam panels. This interface distributes the loads and protects the elastomeric roof membrane . The elevation provides:
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Sufficient snow clearance to prevent the grilles from clogging in winter.
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Better air circulation around the exchanger.
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A reduction in vibrations transmitted to the structure thanks to the isolators under the feet.
We maintain safety recesses all around the condenser, to facilitate maintenance, defrost cycles and heat dissipation by crosswinds.
Route of refrigeration connections and power supply
The UV- insulated copper connections and the communication cable run through a white enclosure to a waterproof feedthrough box . The passage is flashed and then sealed with a membrane by our technicians, in coordination with a roofer if necessary:
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No uncontrolled perforation ,
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Guaranteed waterproofness ,
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Slope respected to avoid any water retention around the header.
Electrically, the unit has a dedicated power supply with an appropriate circuit breaker , nearby circuit breakers, and RBQ/CSA compliant grounding. Everything is protected from UV and shock by rigid conduit and stainless steel cable clamps.
Condensate management and winter service
Summer condensate is not discharged onto the membrane in the immediate vicinity: we route the drain to a point provided for this purpose to avoid puddles and degradation of the coating. In winter, defrost cycles are facilitated by the elevation of the unit; the free space prevents the formation of ice accumulations under the casing. If exposure to the prevailing wind is significant, we add deflectors and snow guards as needed.
Calibration of loads, lengths and voids
Our refrigeration engineers calculate refrigerant charges based on the total length of the lines and the number of elbows, then perform a deep vacuum and measure the leak rate (microns) until stabilization. This protocol guarantees:
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Absence of humidity and air in the circuit,
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Nominal performance in heating and air conditioning,
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Durability of the inverter compressor.
MultiZone Commissioning and Balancing
Each indoor unit is addressed , then the airflows and setpoints are checked room by room. We optimize the distribution so that the outdoor unit does not have short cycles , thus improving:
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The seasonal COP ,
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Acoustic comfort ,
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The longevity of the components.
Results: multi-room comfort, preserved aesthetics and energy savings
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Reliable heating in cold weather, with rapid temperature rise in living areas.
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Precise air conditioning in summer, low noise level outside and inside.
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Low visual impact : no unit on the facade; from the street, the installation is almost invisible .
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Simplified maintenance : safe access via roof hatch, clearances respected, easy cleaning of batteries.
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Operating savings : inverter modulation, more efficient R-32 , fine selection of time slots via remote controls and Wi-Fi options (depending on the head chosen).
AirGreen Tips for Plex Owners in Montreal, Laval, South Shore and North Shore
Choosing the right outdoor location
On a flat roof , choose an area not affected by gusts of wind and away from outlets (kitchen hood, vents) to avoid the suction of greasy or humid air. Provide a stable path for winter maintenance.
Think about snow clearance
Maintain 30 to 45 cm of clearance under the unit and release the grilles as needed. After large drops, a visual inspection ensures unrestricted operation.
Maintaining is saving money
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Internal filters : periodic cleaning, especially during construction or with animals.
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External batteries : gentle rinse in spring, check the fins.
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Annual inspection : checking pressures , tightening electrical connections, updating parameters .
Why AirGreen?
We are a local team dedicated to custom HVAC installation : accurate diagnostics, transparent quotes , grant assistance, and after-sales service renowned for its speed . Our installers master the constraints of Montreal flat roofs: membranes , slopes , flashings , snow and wind management, secure access. The result: heat pumps that last, and customers who call us back for their next projects .
Project Quick Facts
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Type : MultiZone heat pump ( mini-multizone split ) on flat roof .
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Brand : Gree , R-32 refrigerant (new generation).
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Context : plex in Côte-des-Neiges–Notre-Dame-de-Grâce.
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Key details : steel trestle, wooden + HD foam pads, waterproof crossing, anti-UV connections, dedicated power supply, snow clearance, commissioning and balancing piece by piece.
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Benefits : multi-room comfort, preserved aesthetics, high yields in four seasons, simplified maintenance .
Next steps with AirGreen
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100% free on-site assessment to validate suitable lengths, routes and BTU power.
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Detailed proposal including brand , models , performance , costs , deadlines and program eligibility .
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Planning of work according to weather windows and roof access.
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Annual monitoring recommended to maintain performance and warranty .