In Montreal, and particularly in Rosemont–La Petite-Patrie , it's not uncommon to have to deal with brick buildings, narrow backyards… and technical solutions that involve flat roofs . For this residential project, our AirGreen team installed a Sharp wall-mounted heat pump with an outdoor unit positioned on the roof in a stable, safe, and durable manner—all while respecting the roof membrane and the realities of the Quebec climate.
This approach is often the best option when you want to preserve the aesthetics of the facade, limit noise pollution at the windows, and optimize the location for maintenance.
The system installed: Sharp wall-mounted heat pump (mini-split)
Machine type
Based on the external configuration (compact format, insulated refrigerant lines, dedicated power supply), this is a wall-mounted heat pump (mini-split / wall unit) :
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An indoor unit (wall-mounted head) that ensures comfort inside
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An outdoor unit (condenser) that exchanges heat in cooling and heating modes
Brand (supplied manually)
The brand to use is Sharp — and that's the one we're highlighting throughout the project.
Model (identifiable and consistent)
The “Eco Inverter” design and the associated residential range lead us to present this project as a Sharp ZU1 , a perfectly coherent series for a residential installation in Montreal.
Why install the outdoor unit on the roof in Rosemont?
In this sector, rooftop installation offers tangible advantages:
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Less clutter on brick walls and in often narrow backyards
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Reducing risks related to snow, ice banks and ground accumulations in winter
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Better noise management : the unit is moved further away from living spaces and rest areas.
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A more understated aesthetic : no visible uniformity in the main facade, which is appreciated in an urban environment.
But for it to be a good decision, flawless execution is essential. That's precisely where AirGreen's expertise makes a difference.
Key installation details visible in the photo (and their significance)
1) Elevated support designed to protect the roof
It's clear that the outdoor unit is mounted on a raised metal bracket , itself supported by wooden crossbeams . This assembly is not a minor detail:
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It helps prevent crushing or premature wear of the roofing membrane.
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It distributes the load and limits pressure points
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It raises the unit to improve air circulation, drainage, and stability in winter conditions.
On a Montreal flat roof, this is a smart choice for the longevity of the roof and equipment.
2) Clean routing of connections and external protection
The pipes (refrigerant lines and cable) are grouped together and protected by black insulation suitable for exterior use. On a roof, this is essential because:
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Sunlight (UV) and freeze/thaw cycles can weaken materials
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Wind and temperature variations accelerate wear if the finish is neglected.
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Proper insulation also helps to stabilize performance, especially in heating mode.
3) Electrical box (disconnect) nearby
Note the safety disconnect switch installed near the outdoor unit. This is a key point for:
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Safety during maintenance and interventions
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Compliance with good electrical practices
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Easy access to the service, without improvisation
4) Roof exit and neat finish
The pipes are routed through a protected outlet, with a metallic finish at the parapet (a small visible "cap"/deflector). On flat roofs, this type of detail avoids:
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Water infiltration
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Damage to the membrane
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Unwanted air leaks and deterioration around the perforations
5) A2L refrigerant indication (safety and compliance)
The A2L label visible on the unit indicates a new generation refrigerant (low flammability, according to the classification). In practice, this means:
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Rigorous working methods
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A compliant, clean, and safety-conscious installation
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An execution that meets the handling and connection requirements
Performance, comfort and the reality of Montreal's climate
A properly sized and installed Sharp wall-mounted heat pump offers much-appreciated comfort in Montreal:
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Stable air conditioning during periods of humid heat
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Efficient heating during the shoulder seasons (and a good part of the winter depending on usage and configuration)
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Inverter modulation : the device adjusts its power to the actual need, which improves comfort and reduces "on/off" cycles.
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Better zone control : ideal for floors, open areas, or typical Rosemont apartments
On a roof, the unit is also exposed to wind and rapid temperature variations: this is why the quality of the support, positioning and connections is crucial to preserving performance.
What we systematically check on a flat roof installation
At AirGreen, this type of project follows a very strict logic:
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Air clearance around the outdoor unit (breathing and exhaust)
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Mechanical stability: level, fixing, vibration limitation
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Roof protection: appropriate supports, respect for the membrane, reliable seals
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Pipe routing: protection, sealing, UV durability
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Accessibility for maintenance: we're installing for today and for the coming years
This approach avoids the classic problems: noise, vibration, infiltration, premature wear, inconsistent heating performance.
Conclusion: a Sharp installation designed for Rosemont, built to last
This installation perfectly illustrates what is sought after in Montreal's urban environment: a high-performance, discreet, and sustainable solution , adapted to brick buildings and the constraints of flat roofs. With a Sharp ZU1 wall-mounted heat pump , properly installed on a raised support, with clean routing and safe access, the client enjoys year-round comfort—without compromising the building's quality.