Elegant and durable flat roof installation: the AirGreen method for four-season comfort
Context: a house in Outremont and a need for discreet comfort
At AirGreen , we are working in Outremont for a homeowner who wants to air condition his main floor while maintaining the aesthetics of the building and the tranquility of the neighborhood. The choice is oriented towards a Sharp wall-mounted heat pump (recent range with R-32 refrigerant) , recognized for its air conditioning performance and its efficiency in supplementary heating when the mercury drops. The outdoor unit is installed on the flat roof , a popular solution in the central boroughs to free up the facades and keep the noise heard at the windows away.
Why Sharp in R-32 for this project
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High efficiencies and modern fluid : The latest Sharp R-32 generations offer very good SEER/HSPF , reduced fluid charge and better heat recovery potential — a plus for bills and environmental footprint.
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Quiet and clean air : Inverter technology and the presence of purification functions (including Sharp 's own air treatment) contribute to quieter and healthier air conditioning.
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Flexible installation : the wall-mounted configuration allows for rapid distribution in living areas, while the compact outdoor unit is ideal for flat roof mounting with optimal clearance for airflow.
A flat roof HVAC installation designed to last
Membrane support and protection
We place the Sharp outdoor unit on an aluminum frame anchored to treated beams laid flat, in order to distribute the load and preserve the membrane . Anti-vibration pads mechanically isolate the unit from the support and reduce the transmission of vibrations into the structure. The heights are adjusted to ensure:
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free flow of condensates,
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a uniform clearance around the exchanger,
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sufficient snow protection in winter.
When required, we add an EPDM/TPO compatible protective mat under the planks to prevent any abrasion of the membrane due to thermal expansion.
Routing of refrigeration connections: short, protected, aesthetic
On this site, the connections leave the unit through the side and follow a flat route to the point of penetration towards the interior. They are:
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sheathed and continuously insulated , with UV-resistant coating,
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properly bridled to prevent buckling in the wind,
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protected in a watertight conduit at the point of the drilling.
The visible length on the roof remains contained, around 6 to 8 meters , in order to limit pressure losses and maintain the announced performance coefficients.
Inner Head Condensate Management
Inside, the wall-mounted head is positioned to serve the main living area. The drain is secured by gravity to the technical column leading to the roof; when the slope is insufficient, we integrate a compact and silent condensate pump with a current cut-off and non-return valve. Here, the flow is by gravity , which reduces maintenance and noise.
Power supply and safety
On the roof, an external disconnect box in the immediate vicinity of the condenser allows the power to be disconnected during maintenance. The wiring runs in a UV sheath and joins the interior service drop to the circuit breaker dedicated to the panel. We respect the gauge and section recommended by the manufacturer, the clearances around the circuit breaker and the requirements of the Canadian Electrical Code .
The steps that make AirGreen quality
Drilling and sealing
The inward drilling is executed with an outward slope, sleeved, puttyed and capped with a flashing for a lasting waterproof seal. Inside, we close neatly around the chute and the drain, for a clean finish on the wall.
Vacuuming and careful commissioning
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Deep vacuum (< 500 microns) controlled by micronmeter,
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Leak tests and verification of tightening torques using a dynamometer,
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Measurement of temperatures and pressures under real load (cold/hot),
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Setting comfort functions (scanning, auto restart, eco).
Anti-vibration and wind behavior
The flat roof requires attention to wind and resonances : the frame is stiffened, the fixings are braked, the hoses have expansion loops to absorb thermal movements. We validate the stability and the absence of transmission in the roof elements.
Result: measurable comfort and free facade
The result is doubly beneficial:
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Inside , the heat pump ensures a rapid drop in temperature and humidity during heat waves, with gentle diffusion and precise control of the setpoint.
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Outside , the facade is clear, noise from the windows is reduced and the unit is protected from ground impacts. Maintenance is carried out on the roof, without disturbing the occupants.
Maintenance and best practices for longevity
Recommended HVAC maintenance
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Wall head filters : rinse every 4 to 8 weeks during use.
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Annual inspection by us: cleaning of the exchanger, amperage test, parameter check, verification of supports, UV sheath and cable glands.
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Occasional snow removal around the unit during blowing snow episodes to avoid accumulations on the battery.
Wise use
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In air conditioning , aim for 23–24°C as the setpoint: best comfort/energy compromise and fewer short cycles.
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For heating , favor a stable setting and the use of eco modes when the load is low (mid-season).
Grants and Eligibility
Sharp 's new generation R-32 wall-mounted heat pumps may be eligible for provincial programs based on capacity and low-temperature performance (certified models, HSPF/SEER thresholds, −25/−30°C operating ranges). Our team verifies for each project:
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the exact reference installed and its compliance with the lists of accepted devices,
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documentary requirements (detailed invoices, serial numbers, technical sheets),
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optimization of the assembly (line lengths, clearances) in order to preserve the performance necessary for admissibility.
We support our clients in Montreal , Laval , Longueuil , North Shore and South Shore in preparing the file until the final submission.
Pitfalls avoided on the flat roofs of downtown Montreal
Membrane wear
Poorly distributed support or overly hard feet can damage the membrane. Our planks and pads ensure load distribution and protection against abrasion, even during thermal expansion.
Unprotected lines
UV rays and wind accelerate the aging of insulation. We cap and clamp each section, respecting the bending radii to avoid stress on the connections.
Insufficient clearances
On narrow roofs, air intake can be disrupted by a high parapet or chimney. We position the unit outside the recirculation zone , taking into account obstacles, to maintain nominal performance.
Why AirGreen for your HVAC installation in Outremont and Greater Montreal?
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Urban expertise : mastery of the architectural constraints of flat roofs, access via hatches, management of loads and safety at height.
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Exemplary finishes : straight lines, clean trunking, waterproof cable glands, disconnect box within easy reach.
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Complete service : selection of the right wall-mounted air conditioner / wall-mounted heat pump , installation, HVAC maintenance , grant assistance and after-sales follow-up.
Condensed technical sheet of the installation in Outremont
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Type : Sharp wall-mounted heat pump , R-32 range
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Installation : on flat roof on aluminum frame and logs with anti-vibration pads
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Refrigerated route : UV conduit/sheath, visible length ~ 6–8 m , sealed penetration
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Condensates : gravity evacuation to technical column
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Electrical : roof disconnection , dedicated circuit conforming to the recommended gauge
Need discreet comfort on a flat roof?
Whether you are in Outremont , Montreal , Laval , Longueuil , on the North Shore or the South Shore , we design and build careful HVAC installations, adapted to urban buildings, with clean finishes and measurable performance all year round.