Installation of a Gree wall-mounted heat pump on a rooftop terrace in Southwest Montreal
In this condo in southwest Montreal, AirGreen installed a Gree R-32 wall-mounted heat pump on a rooftop terrace, with a raised support, membrane protection, and neat connections. The client now enjoys consistent and energy-efficient comfort, both summer and winter.
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The job on one screen
The article, chapter by chapter
In this project, carried out in a modern home in Southwest Montreal, our team was tasked with installing a Gree wall-mounted heat pump , providing year-round comfort without obstructing the facade or living space. The building's configuration—a flat roof with terrace access and modern wood and fiber cement siding—was perfectly suited to a rooftop installation, provided the membrane was protected and optimal winter performance was guaranteed.
The context: an urban condo, very real constraints
The client lives in a townhouse-style condo, typical of the Southwest: flat roof, access via patio door, contemporary siding and little available floor space.
His objectives were clear:
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To effectively cool the main living area in summer.
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Benefit from efficient heating even at low temperatures to reduce the use of existing electric heating.
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Preserve the aesthetics of the building and avoid unnecessarily piercing the roof membrane .
We therefore opted for a Gree wall-mounted heat pump with an Inverter compressor, R-32 refrigerant , with an indoor wall unit in the living room, and an outdoor unit installed on the roof.
Equipment choice: Gree, efficiency and R-32
For this project, we opted for a Gree R-32 wall-mounted heat pump, Lomo+ type (12,000 BTU) , a model perfectly suited to Montreal apartments and condos:
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Inverter technology to continuously modulate power and avoid on/off cycles.
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R-32 (A2L) refrigerant: more efficient and with a lower warming potential than R-410A.
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An excellent compromise between winter heating, summer air conditioning and a very low noise level.
This type of Gree wall-mounted heat pump allows the customer to benefit from:
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Offering consistent comfort in both summer and winter.
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Reduced electricity consumption thanks to the system's high efficiency.
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With a very low level of external noise , essential in a dense urban environment.
A neat, elevated installation on the roof
The photo clearly illustrates the unique nature of this project: the outdoor unit is installed on the roof, on a raised aluminum support .
Membrane support and protection
We have :
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A sturdy, corrosion-resistant aluminum bracket was used.
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Place this support on treated wood beams and wide footings, in order to distribute the load and protect the roof membrane.
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A clearance of approximately 40 cm above the roof surface is planned, sufficient to remain clear in case of light snow accumulation and to facilitate manual snow removal if necessary.
This approach avoids anchoring directly into the membrane, while ensuring excellent mechanical stability against wind.
Vibration and noise management
The raised support, combined with our fixing method, minimizes:
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The transmission of vibrations to the building structure.
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Sound resonances, often perceptible inside lightweight constructions.
Result: the Gree unit operates discreetly, even in an environment of closely spaced condos.
Finishing touches to the connections: clean, safe and aesthetically pleasing
As always at AirGreen, we place great importance on the quality of the connections and the visual finish.
Refrigeration lines and power supply
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The insulated refrigerant pipes , communication cable and condensation drain are bundled together in a white vertical external trunking , which runs down the wall to the indoor unit.
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The refrigeration connections are accessible on the side of the Gree unit, allowing for easy maintenance and quick future diagnostics if needed.
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The power supply is provided on a dedicated circuit , conforming to the electrical requirements for this type of equipment.
This finish makes the installation discreet when on the terrace, while also facilitating the work of technicians during maintenance visits.
Four-season comfort in a demanding Montreal climate
In Montreal, a wall-mounted heat pump is not just an air conditioner: it must efficiently heat a good part of the winter.
With this Gree R-32 wall-mounted heat pump , the customer benefits from:
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Efficient heating at low temperature (down to approximately −25 °C according to manufacturer's specifications).
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It features an inverter system that adjusts power according to demand, thus avoiding large temperature variations.
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With very stable comfort in the area served by the wall head, ideal for the open living-kitchen area.
In summer, the same device provides efficient air conditioning and dehumidifies the indoor air, significantly improving the feeling of comfort on hot and humid days typical of the Southwest.
Recommended maintenance and system longevity
To keep this Gree heat pump in top condition for many years, we recommend:
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Regular cleaning of the internal head filters (every 1 to 3 months depending on usage).
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Full annual inspection by our team: pressures, electrical connections, condensate drainage, condition of supports and membrane around the installation.
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Visual inspection in winter to ensure that snow does not accumulate in front of the unit or under the support.
A careful installation like this, combined with good maintenance, generally maximizes the lifespan of the heat pump and preserves its energy performance.
AirGreen: Your partner for Gree heat pumps in Montreal
This project in Southwest Montreal perfectly illustrates what we do every day:
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Analyze the architectural reality of each building.
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To offer the best wall-mounted heat pump solution according to usage, budget and desired comfort.
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To create clean, sustainable facilities adapted to the Quebec climate .
If you live in a condo or townhouse in the Southwest, in Verdun, Rosemont, Villeray or elsewhere in Greater Montreal, and you are considering installing a Gree wall-mounted heat pump , our team will be happy to advise you.
We can visit your residence, assess the possibilities (wall-mounted, multi-zone, central), and offer you a turnkey solution: equipment selection, installation, commissioning and after-sales support .
Do you want four-season comfort comparable to this project with a Gree heat pump installed on a roof terrace or on a wall bracket?
Contact us at AirGreen : we will be delighted to study your project and support you from the first call to the first day of comfort in your new system.
The job tools
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
How the job unfolds
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
What we check on a job like this one
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
The right pages, at the right time
Four statements: true or false?
It all comes down to details you have just seen.
1. In heating mode, the outdoor unit can produce water.
During defrost cycles. That water must drain away without forming ice.
2. You pick the capacity with a simple square-footage rule.
Windows, insulation, orientation and how the room is used all count. Capacity is chosen on site.
3. A multi-zone connects several indoor heads to a single condenser.
One head per room, all on the same condenser. Each room keeps its own temperature.
4. The disconnect can sit behind the patio furniture.
It must stay accessible: it is what shuts the unit off for service.
0 / 4 right answers
What people ask us about this kind of work
Does a wall-mounted heat pump heat in winter?
Wall-mounted or multi-zone: how do I choose?
Where does the outdoor unit go?
Are there grants?
Do I need a permit?
How cold can it heat?
How much can I save?
How is the LogisVert assistance calculated?
Is it noisy?
The outdoor unit is covered in ice: is that normal?
Does AirGreen hold the required licences?
Is the estimate free?
No question matches. Write to us: we answer.
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).