Installation of a Gree central heat pump on a flat roof in Ahuntsic-Cartierville
Installation of a Gree central heat pump on a flat roof in Ahuntsic-Cartierville: a high-performance and durable HVAC solution adapted to Greater Montreal winters.
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.
It captures or rejects heat outside. It sits on a level base, above the snow, with free space all around.
The insulated refrigerant lines enter the house through a sealed opening and run to the indoor coil.
A shut-off switch near the outdoor unit isolates it safely for service.
Sitting on the indoor module, it moves heat between the house air and the refrigerant.
Electric furnace or air handler: its fan pushes air through the ducts. The electric backup takes over in extreme cold.
Supply ducts bring air to the rooms; returns bring it back to the unit. Their condition matters as much as the unit's.
It protects the coil and the fan. A dirty filter cuts airflow, so it gets checked regularly.
It runs the heat pump and the backup heat. It must be compatible with the installed system.
An HVAC installation project adapted to Montreal's harsh winters
At AirGreen , we know how challenging Montreal's climate is for heating and cooling systems. In this project in Ahuntsic-Cartierville , we installed a Gree central heat pump on the flat roof of a residential building. This configuration is particularly demanding due to winter conditions: heavy snow, ice, wind, and extreme temperature variations.
Our team designed a robust, secure installation perfectly adapted to the Montreal context, guaranteeing optimal comfort for occupants throughout the year.
Why choose a Gree central heat pump for Montreal?
The Gree brand is now one of the world's largest HVAC manufacturers, renowned for the reliability and durability of its equipment. In this case, the chosen model allows:
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Stable performance down to -25°C , suitable for Greater Montreal winters.
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Quiet and energy-efficient operation.
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Compatibility with Quebec subsidy programs (LogisVert, Transition Énergétique Québec, etc.).
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Increased durability thanks to corrosion-resistant materials, essential in environments where salt and humidity are omnipresent.
Technical features of this installation
Flat roof support
The device was installed on a raised metal structure , securely fixed and secured with chains to resist winds. This elevation allows:
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Keep the condenser above snow level.
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Ensure optimal air circulation.
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Facilitate maintenance and natural defrosting.
Routing of refrigeration pipes
Electrical conduits and wiring are protected by insulated capping along the roof, ensuring both aesthetics and mechanical protection against frost and moisture. This treatment prevents water infiltration and heat loss.
Snow and Frost Management
Montreal experiences rapid snow accumulation. To avoid obstruction of the fans, the unit is installed at a sufficient height, and the area around the condenser remains clear for proper operation in heating mode.
Security and Compliance
The entire installation complies with current electrical and mechanical standards in Quebec. Our RBQ-certified technicians oversee every detail, including:
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Sizing of cables and circuit breakers.
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Perfect alignment of refrigeration pipes.
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Commissioning with full performance testing.
Challenges encountered and solutions provided
1. Winter conditions on the day of installation
Snow on the roof made access and securing difficult. We used anti-skid devices and secured the work area to ensure the team's safety.
2. Long-term protection of the outdoor unit
To prevent premature deterioration, we applied an additional layer of anti-corrosion protection and validated the stability of the structure against freeze/thaw cycles.
3. Aesthetic and durable routing of conduits
Rather than leaving cables and pipes exposed, we opted for a protected route, guaranteeing not only better thermal performance, but also added aesthetic value for the building.
Benefits for the customer
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Year-round comfort : reliable heating in winter, efficient air conditioning in summer.
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Energy savings : reduced heating costs compared to an electric furnace alone.
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Access to subsidies : thanks to the high efficiency of the heat pump, the owner will be able to benefit from financial programs.
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Long-lasting installation : resistant to the extreme climatic conditions of Greater Montreal.
AirGreen: your HVAC partner in Montreal, Laval, North Shore and South Shore
This installation in Ahuntsic-Cartierville demonstrates our expertise in residential HVAC systems designed for the harshest winters. Whether it's a house, a plex, or a residential building, we design custom solutions that combine performance, durability, and comfort.
Our teams operate in Montreal, Laval, Longueuil, the North Shore and the South Shore , always with the same focus on quality and customer satisfaction.
How it goes, from the first call to the end
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the ducts, the current indoor module, the electrical panel and the planned spot for the outdoor unit.
The equipment combination, capacity and price, in writing. We check whether the combination qualifies for assistance programs.
Access protected, old unit disconnected and removed when it is being replaced.
Electric furnace or air handler, with its coil, connected to the supply and return ducts.
On a level base, raised above the snow, with free space all around.
Insulated, they enter through a sealed opening and run to the indoor coil.
Dedicated circuits, accessible disconnect, a thermostat that works with the heat pump and the backup heat.
Leak test, vacuum, start-up, airflow check and a test of both modes.
Filter, thermostat, backup heat in extreme cold: what to know before winter.
- The on-site estimateWe look at the ducts, the current indoor module, the electrical panel and the planned spot for the outdoor unit.
- The quoteThe equipment combination, capacity and price, in writing. We check whether the combination qualifies for assistance programs.
- Getting readyAccess protected, old unit disconnected and removed when it is being replaced.
- The indoor moduleElectric furnace or air handler, with its coil, connected to the supply and return ducts.
- The outdoor unitOn a level base, raised above the snow, with free space all around.
- The refrigerant linesInsulated, they enter through a sealed opening and run to the indoor coil.
- Electrical and thermostatDedicated circuits, accessible disconnect, a thermostat that works with the heat pump and the backup heat.
- Tests and start-upLeak test, vacuum, start-up, airflow check and a test of both modes.
- The walkthroughFilter, thermostat, backup heat in extreme cold: what to know before winter.
And at your place?
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.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Check the indoor module's filter.
- Clear winter debris from the outdoor unit.
- Test cooling before the heat arrives.
- Check the filter more often in peak season.
- Keep registers and returns clear.
- Watch condensate drainage near the coil.
- Change or clean the filter.
- Test heating and backup heat before the cold.
- Book periodic maintenance.
- Clear snow around the outdoor unit.
- Store nothing in front of the indoor module.
- Note any unusual noise or smell and call us.
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What people ask us about this kind of work
Can I keep my current ducts?
What happens in extreme cold?
Furnace, air handler, ducted: what is the difference?
Are there grants?
Do I need a permit?
How much can I save?
How is the LogisVert assistance calculated?
Will my current thermostat work?
Central or wall units: which one?
Does AirGreen hold the required licences?
Is the estimate free?
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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).