In this project, our team was called into a typical Rosemont–La Petite-Patrie duplex, with a white flat roof and a small wooden superstructure providing access to the terrace. The owners' objective: to replace old, noisy, and energy-inefficient units with two new-generation Gree wall-mounted heat pumps , capable of ensuring comfort in both summer and winter without compromising the roof's airtightness or the natural light from the large central skylight.
Context: two areas to be air-conditioned and heated
The building comprises two separate living spaces on the upper floor, each requiring its own system. The chosen solution:
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Two Gree wall-mounted single-split outdoor units , each dedicated to a zone;
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Discreet interior wall-mounted lights (not visible in the photo) installed in the main living areas;
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Priority is given to quiet operation , energy efficiency and reliability in Montreal winters.
The latest generation of Gree wall-mounted heat pumps with Inverter compressors represents an excellent compromise between comfort, performance and budget, while reducing electricity consumption compared to baseboard heaters or an electric furnace.
Installation on a flat roof: planning and preparation
Installing heat pumps on a flat roof in Montreal requires careful technical planning. We have taken the following into account:
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Roof membrane waterproofing : no unnecessary drilling, use of self-supporting bases.
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Respecting the clearances around the light well : preserving natural light and allowing safe access for maintenance.
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Air circulation : the units are clear of walls and railings to avoid recirculation of hot or cold air.
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Accessibility for maintenance : sufficient space in front of each unit for seasonal inspections.
Before installing anything, we checked the roof structure and the available area in order to distribute the loads and leave a safe passage area between the equipment and the glazed skylight.
Installation details visible in the photo
Several important elements are clearly visible in the image:
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Two Gree capacitors installed on raised galvanized steel supports , themselves placed on bases which distribute the load over the roof membrane.
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Treated wooden pieces serve as shims and stabilizers, allowing for level adjustment and vibration reduction.
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The central skylight is protected: the units are positioned so as not to obstruct the supply of light or the flow of water.
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The planned passage for the refrigeration lines and the power supply along the wooden facade, which will then be protected by aesthetic UV-resistant covers.
This elevated configuration is essential in Quebec's climate: it keeps the devices above the snow accumulation, facilitates eventual snow removal and allows proper drainage during episodes of rain and thaw.
Key steps in our intervention
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Site analysis and planning
We started by validating the optimal location on the roof: clearance from the edges, minimum distance between the two Gree capacitors and access to the pipe passage to the inside. -
Roof protection
Installation of the footings and pads to distribute the load without puncturing the membrane. Each support is carefully positioned to avoid areas of ponding (stagnant water). -
Installation of Gree outdoor units
Fixing the brackets, installing the two Gree wall capacitors, installing the anti-vibration mounts, checking the level and tightening of the hardware. -
Refrigeration and electrical pathway
Connection of refrigerant lines to indoor units, brazing, vacuuming and leak testing. Electrical connection compliant with the Code, with circuit breaker and external disconnect switch. -
Commissioning and settings
Checking pressures, blowing temperatures, calibrating remote controls, programming heating/cooling modes according to occupants' needs.
Performance and comfort in Montreal winters
Even though the photo was taken during warmer weather, the system is designed primarily for Quebec winters :
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The Gree wall-mounted heat pumps installed are designed to maintain good heating capacity in cold weather, much more efficient than electric baseboard heaters.
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The elevated installation limits the risks due to snow and ice on the fans and heat exchangers.
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The clearance around the units allows for efficient defrosting , which improves the durability of the equipment and reduces unexpected shutdowns.
The result: occupants will benefit from stable, comfortable and economical heating, while also enjoying efficient air conditioning during summer heat waves.
Results for Rosemont owners
At the end of the construction, the owners now have:
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Two independent air conditioning and heating zones , each controlled according to actual needs;
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A clean, aligned and safe installation, integrated into the roof without compromising the brightness of the skylight;
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A reliable, quiet and energy-efficient Gree system, adapted to the reality of Montreal's flat roofs.
This configuration not only improves comfort, but also the value of the plex, a major asset in a market where buyers are looking for well-air-conditioned and economically operated housing.
Why choose AirGreen for your Gree heat pumps in Montreal?
At AirGreen, we install Gree wall-mounted heat pumps throughout Greater Montreal, particularly on flat roofs in Rosemont, the Plateau, Villeray, and central neighborhoods . We combine:
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A detailed knowledge of Montreal buildings (triplexes, condos, extended floors on the roof);
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Teams continuously trained on new generations of wall-mounted heat pumps;
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Particular attention is paid to the aesthetics, acoustics and waterproofing of the roof;
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A responsive after-sales service for maintenance and adjustments.
If you are also considering installing a Gree flat roof heat pump in Montreal , our team will take care of everything: load study, placement, complete installation, commissioning and support for subsidies when applicable.