A flat roof construction site designed to last, quiet and ready for Montreal winters
On a typical building in Rosemont–La Petite-Patrie, we are installing a Gree wall-mounted heat pump ( Livo R32 range), with a condenser mounted on a raised stainless steel support. The objective: to combine four-season comfort, high cooling efficiency and reliability on a flat roof exposed to the weather of Greater Montreal .
Project context and client needs
The client wanted to air-condition the main living area and provide efficient supplemental heating during cold spells. The main constraint was a lack of floor space and the impossibility of installing brackets on the façade. The solution chosen was to install the condenser on the gravel roof, with management of the refrigeration paths up to the interior head.
Technical choice: Gree Livo R32 for the cold of Quebec
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R-32 refrigerant : better seasonal efficiency and reduced charge.
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Extreme cold operating range : ideal for Montreal and Laval.
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Quiet : variable speed fan and compressor, perfect for roofs close to windows.
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Grant compatibility : performance that generally meets the criteria of current energy efficiency programs (depending on availability and configuration).
Installation details – flat roof, structure and anti-vibration
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Support : stainless steel frame, anchored on treated logs resting on rigid insulation and anti-abrasion layer; sufficient height for snow management and drainage.
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Anti-vibration : blue pads under the support points limiting transmission to the roof.
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Electrical : Adjacent outdoor disconnect and dedicated circuit; UV-resistant wiring routed neatly through the trunking to the point of penetration.
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Refrigeration path : approximately 12 m from the roof to the interior head, with discreet capping on the rear facade; continuous high-density insulation carrier.
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Piercing : waterproof penetration with vapor barrier and flashing suitable for flat roof membranes.
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Condensate management : gravity drainage from the interior head to the exterior; controlled slope to avoid stagnation.
Why a raised condenser here?
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Durability : The elevation protects the device from meltwater and ice.
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Easy HVAC maintenance : Minimum clearance of 12–18" around the unit for full access.
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Winter performance : better airflow, less frost recirculation.
Aesthetic and acoustic integration
We favor a rear routing invisible from the street, ducts painted to match the cladding, and anti-vibration installation. The result: discreet operation, in line with the neighborhood requirements of Montreal's boroughs.
Key stages of the project
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Survey: measurement of spans, inspection of the membrane and drains.
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Preparation: temporary protection of the gravel, fabrication of the chassis and marking of the route.
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Installation of the bracket and the disconnector; alignment and load tests.
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Drawing of lines, brazing under nitrogen and continuous insulation.
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Deep vacuum , leak testing, charging and commissioning.
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Calibrations: flow rates, defrosting instructions, intensities verification.
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Discount: Demonstration of HVAC modes, filters and maintenance reminders.
Measurable results for the client
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Quick comfort in summer, stable support in mid-season.
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Lower consumption compared to the old portable air conditioner.
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Reduced exterior noise level thanks to decoupled support and night mode.
AirGreen Operating Tips
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Maintain clearances around the unit, especially in winter.
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Program a frost protection mode during prolonged absences.
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Clean the inner head filters every 4 to 6 weeks during the season.
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Schedule annual HVAC maintenance : static pressure, load, vacuum gauge, defrost cycle checks and chassis fastener inspection.
Things to watch out for on Montreal flat roofs
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Snow and ice : check after major episodes; clear the grilles if necessary.
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Drainage : Ensure that drains do not back up into the unit.
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Radiation : A lightweight shield can improve the longevity of plastics without impeding airflow.
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Paths : avoid pedestrian crossings on refrigeration lines; protect with rigid capping.
Why choose us for your HVAC installation in Montreal, Laval, Longueuil, North Shore and South Shore?
Our team is adept at addressing the challenges of complex and condominium developments: access, roofing logistics, coordinated schedules, membrane compliance, and photo reports for property managers. Each file includes precise sizing (BTU/zone), a maintenance sheet, and energy optimization advice tailored to the building.
What if your project is different?
Single-family home in Laval , condo in Longueuil or duplex on the North Shore / South Shore : we adapt the solution (single wall-mounted, MultiZone Heat Pump , cassette or ducted ) with the new generations R-32 / R-454B and subsidy support when applicable.