A roof installation designed for longevity: protected membrane, anti-vibration structure, short cooling path and professional sealing of the parapet
Urban context and client objectives
In Plateau-Mont-Royal , we are working on a typical flat-roofed building. The owner wants a compact heat pump to air-condition an upper unit and provide stable heating support during the off-seasons, without occupying the courtyard or balconies. Access is via the roof hatch; the gravel surface requires special attention to the membrane and wind resistance.
Selected device: Sharp Eco Inverter
We install a Sharp Eco Inverter with inverter technology and Plasmacluster filtration on the indoor unit side. This range is popular for:
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its fine modulation which stabilizes the temperature and reduces consumption ;
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its silent operation in dense environments;
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reliable electronics, adapted to the thermal variations of Greater Montreal .
BTU sizing is based on the actual air-conditioned area, orientation, and insulation level. This step prevents short cycles, excessive frost, and energy-consuming restarts.
Installation on a flat roof: dedicated structure and membrane protection
The outdoor unit is placed on an above-ground aluminum support , anchored on distribution soles placed on protective cushions (rails with EPDM mats) so as not to perforate the membrane. This choice guarantees:
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uniform diffusion of loads on the gravel;
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sufficient clearance for air sweeping and defrost water drainage;
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the possibility of maintenance under the device without direct contact with the roof.
We add anti-vibration pads under the support plates to limit transmission to the building during defrost cycles.
Wind and clearance management
On a roof, wind resistance is essential. We:
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orient the condenser with its back to the parapet to break the dominant gusts;
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respect the clearances at the front and on the sides to avoid any recirculation of air;
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validate the height of the support to stay away from the snow drifts without exceeding the guardrails;
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We provide clear maintenance access from the hatch, with a secure path.
Refrigeration route and sealing of the parapet
The line set (insulated copper + communication cable) and the drain are guided in a UV sheath . The passage is made above the parapet , in a sleeve lined then sealed with polyurethane to maintain the watertightness and block water infiltration. Inside, the route remains short and straight up to the wall head, which reduces pressure losses and promotes seasonal performance.
Electricity and compliance
We install a readily accessible, waterproof, and labeled outdoor disconnect box . The dedicated circuit is drawn from the main panel using a double-pole circuit breaker and a conductor cross-section suitable for the machine's amperage. The conduits, cable glands, and cables are approved for outdoor use and for the temperature variations encountered on roofs.
AirGreen commissioning
Our startup protocol includes:
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nitrogen test to validate the tightness of the solders;
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deep vacuum (≤ 500 microns) and rise test to eliminate humidity;
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load opening, current measurements, superheat and subcooling ;
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checking the delta T at the interior vents in cold then in heat;
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activation of nighttime silent mode and instructions adapted to the accommodation.
Execution details visible in the photo
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Aluminum support on protective rails placed on the gravel;
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wiring and line-set in a clear sheath, running up to the parapet , where a technician carries out the proper sealing with polyurethane mastic;
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free clearances around the device and presence of roof ventilation elements respected.
Condensate and winter management
Even if the unit is on a roof, winter defrost water must be channeled to prevent stagnation. We create a slight slope under the support towards a drainage area and check that there is no projection against the parapet. The height of the support limits the formation of snow banks around the condenser.
Result: comfort and discretion for superior accommodation
The customer gets rapid cooling in the summer, efficient additional heating in the spring and autumn, and above all a discreet installation, invisible from the street and silent for the neighbors. The installation on a flat roof completely frees up the facades and balconies.
Recommended HVAC maintenance
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Remove leaves and debris from around the condenser each season.
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Gently rinse the external battery in the spring (low pressure water).
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Clean the indoor unit filters every 4 to 8 weeks during heavy use.
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Plan annual HVAC maintenance : pressures, intensities, probes, electrical tightening, checking the sealing of the parapet and condition of the roof cushions .
Pitfalls to avoid on roofs (feedback)
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Piercing the membrane: to be avoided - always favor above-ground supports with pads.
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Install too close to a ventilation air intake : risk of recirculation — respect clearances.
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Line-set not UV protected: accelerated aging — use a resistant sheath and a durable sealant .
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Forgetting to disconnect nearby: non-compliant and dangerous for maintenance.
Grants and funding
High-efficiency wall-mounted heat pumps are often eligible for assistance programs based on their seasonal performance and cold weather capabilities. We validate the eligibility of the installed Sharp configuration, prepare the files and offer financing options for Montreal , Laval , Longueuil , the North Shore and the South Shore .
Why AirGreen for your flat roof HVAC installation ?
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Specific expertise in flat roofs : membrane protection, anchoring, clearances and wind resistance.
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Documented and measured commissioning methodology .
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Durable finishes : EPDM rails, clean sealing, UV sheath, aluminum support and anti-vibration .
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Responsive after-sales service , with HVAC maintenance contracts adapted to urban buildings.
Launch your project
Do you have a superior home in Plateau-Mont-Royal , in the Southwest , in Ville-Marie or elsewhere in Greater Montreal? We size the ideal BTU , check the subsidies and deliver a clean, quiet and durable flat roof installation. Fast intervention in Montreal , Laval , Longueuil , on the North Shore and the South Shore .
Areas served : Montreal, Laval, Longueuil, North Shore, South Shore.
Services : HVAC installation , replacement, energy optimization and HVAC maintenance .