A flat roof installation designed for longevity, performance and acoustic discretion
Context and objectives of the project
At AirGreen , we were approached by the owner of a typical Outremont residential building—red brick, flat roof , mature vegetation—who wanted to stabilize comfort in both summer and winter without cluttering the backyard or the facades. We recommended a Sharp wall-mounted heat pump from the ZU1 (R-32) range , chosen for its low-temperature heating efficiency, its regulated inverter operation, and its low noise level for neighbors.
What we install on the roof
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Sharp ZU1 (R-32) outdoor unit mounted on a raised galvanized steel frame ;
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Wooden distribution pads and sliding rails placed on protective soles to preserve the membrane;
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Refrigerant connections and communication cable in a UV-resistant grey capping , running to the parapet and then to the technical duct;
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Condensate management adapted to the interior architecture (priority to gravity, pump only if necessary).
This configuration provides sufficient ground clearance for drainage, snow removal and maintenance access, while avoiding compression points on the bituminous membrane.
Why the Sharp ZU1 (R-32) range for Outremont
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High seasonal efficiencies thanks to R-32 refrigerant, more efficient than the older generation R-410A at reduced charge.
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Reliable heating in cold weather specific to Greater Montreal ; the operating range is sized for prolonged freezing episodes.
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Compact and quiet : continuously modulating inverter fan and compressor, ideal for dense residential environments.
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Potential eligibility for programs : a high-performance, Energy Star -certified wall-mounted heat pump can open the door to incentives in Quebec depending on power and efficiency; we support our customers in Montreal, Laval, Longueuil, North Shore, and South Shore to verify eligibility.
Installation details: the AirGreen method on a flat roof
Load distribution and membrane protection
We place the chassis on wooden rails resting on non-slip synthetic soles . The objective: to distribute the load , avoid unnecessary perforation and facilitate snow removal . The chassis anchors are tightened to the recommended torque; the anti-vibration pads limit structural transmission.
Clearances and airflow
The Sharp unit is positioned to provide rear and side clearance in accordance with the manual, with a discharge free of any obstructions. On a flat roof, this precaution prevents the recirculation of hot air, which would degrade the heat exchange.
Route of the links
The straight capping protects the insulated copper tubes and cable from UV rays and shocks. The bending radii are respected; the retaining collars are regularly spaced for a clean and stable route in the wind.
Waterproofing and passages
When a penetration is required, we integrate a roof pass-through with membrane-compatible flashing and elastomeric sealant, in order to maintain the watertightness of the complex. No unprotected screws are left in contact with the roof.
Interior: precise comfort and sobriety
The wall-mounted fan serves the most heavily used daytime area. Horizontal/vertical diffusion is adjusted to avoid direct airflow. The washable filters can be removed without tools. The heating , cooling , dehumidification and frost protection modes cover all needs, with optimized consumption thanks to inverter control .
Commissioning and quality controls
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Nitrogen test and deep vacuum to micron before opening the valves;
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Checking currents , superheating/subcooling , and reading supply/return temperatures ;
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Registration of the series for warranty, and delivery of a user/maintenance guide to the customer.
Results obtained
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Stable cooling in summer, especially during hot spells;
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Economical heating over long periods of the year, relieving the burden on electric convectors;
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Quiet for occupants and neighbors thanks to location, anti-vibration and speed control;
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Careful integration respecting the aesthetics of Outremont roofs.
Best practices for flat roofs in Greater Montreal
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Pre-inspection of slope, drains and membrane condition; before/after photo report.
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Load distribution via continuous soles; never concentrated pressure points.
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Wind management : Frame height and bracing adapted to exposure; cable routing without floating loops.
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Clearances maintained even in winter; plan for snow management in front of the interchange.
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Clear and serviceable route of connections ; continuous capping and generous radii.
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Acoustics : pads, controlled tightening, elimination of chassis resonances.
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Electrical : dedicated circuit breaker, compliant rating, accessible external disconnect box (when required).
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Maintenance : washing of external batteries, annual check of parameters; cleaning of internal filters every 1–2 months during peak use.
Daily usage tips
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Set a stable setpoint rather than large deviations; the inverter works better in maintenance mode.
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Keep the outdoor unit clear (leaves, snow, objects).
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Use the dehumidification mode in summer on humid days for increased comfort at moderate settings.
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Schedule annual HVAC maintenance : it extends lifespan and secures performance.
Scalability and options
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Subsequent passage in multi-zone if other parts need to be treated;
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Addition of an air exchanger to improve air renewal in a very airtight dwelling;
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Integration with a smart thermostat/control for away scenarios.
Typical process with AirGreen
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Technical visit : measurements, length calculations, electrical verification.
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Installation : generally in one day for a flat roof area, including frames, connections, commissioning.
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Grant support : we validate eligibility and prepare the file according to the criteria in force in Montreal, Laval, Longueuil, North Shore, South Shore .
Why AirGreen in Outremont
Our teams understand the constraints of narrow alleys , rooftop access , nearby parks, and condominium regulations . We deliver a durable, aesthetically pleasing HVAC system optimized for Montreal's climate, with responsive local service for maintenance and follow-up.