Optimized four-season comfort on a flat roof for a residential building
At AirGreen , we adapt each HVAC installation to the architecture and the actual uses of the occupants. In this Outremont building, our mandate is to deploy several Fujitsu wall-mounted heat pumps with outdoor units on the roof to provide efficient heating in winter and economical air conditioning in summer, without encroaching on the balconies or distorting the facades.
Building profile and client objectives
The building features a white elastomeric membrane roof, typical of Montreal plexes, and includes several apartments. The owner wishes to:
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reduce operating costs by modernizing equipment,
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improve comfort room by room,
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limit the visual footprint on the street,
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simplify maintenance thanks to easy accessibility from the roof.
The wall-mounted heat pump is essential here: an indoor head per priority zone (living room, master bedroom), and a compact Fujitsu condenser on the roof, installed on release supports to preserve the membrane.
Why choose Fujitsu for Outremont and Greater Montreal
Fujitsu is recognized for:
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reliability in cold climates (stable operation down to -25°C on suitable residential ranges),
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high efficiencies (advantageous SEER/HSPF) to reduce energy bills,
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a contained noise level both inside and outside, essential in a dense urban environment,
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broad multi-housing compatibility : progressive deployment per apartment, simple maintenance, readily available parts.
Under current programs, many Fujitsu models meet Energy Star criteria and may be eligible for grants . Our team systematically supports owners to maximize eligibility.
Installation Details: AirGreen Method
Roof installation and membrane protection
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The condensers are placed on raised supports with anti-vibration pads, ensuring sufficient clearance for drainage and snow.
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The support points are placed in such a way as to distribute the loads and avoid any puncture of the membrane.
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The mechanical and electrical routes run along the parapet elevations, then cross to the dwellings via perfectly sealed crossing boxes .
Power supply and control
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Each outdoor unit receives a nearby disconnect box for safety and maintenance.
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Control and power wiring follows rigid capping to protect the conductors from UV, water and ice.
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We calibrate dedicated circuit breakers according to the device nameplate and the Quebec Electrical Code.
Refrigeration lines and insulation
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The refrigeration lines are sized according to the actual lengths and the differences in level between the roof and the rooms served.
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The insulation is continuous, UV-resistant and vapor-barrier on the warm side, to prevent condensation in Montreal's humid summers.
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Flare fittings are torqued, then nitrogen and deep vacuum tested before topping up to the prescribed weight.
Condensate management
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When the configuration allows it, we favor gravity flow towards a drainage point on the roof, avoiding the use of a lifting pump.
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If a pump is required inside, it is fitted with an overflow alarm and a non-return valve, and its maintenance is included in the annual plan.
Orientation, airflow and clearances
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The outdoor units comply with Fujitsu's recommended discharge clearances to prevent recirculation of hot air.
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The layout takes into account existing elements (skylights, vents, low walls) to ensure free air circulation and limit the transport of particles on the roof.
What the owner earns
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Targeted comfort : each zone receives the necessary power, with precise temperature control.
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Free space : nothing on the balconies or in the courtyard, all the machinery is concentrated on the roof.
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Silence : Fujitsu wall-mounted air conditioners and their compact condensers limit noise pollution, an asset for Outremont.
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Savings : Thanks to high efficiency and careful HVAC installation , energy bills are reduced.
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Simplified maintenance : quick access via the roof, cut-off points within reach, efficient annual checks.
Technical highlights of this project
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Flat roof with multiple condensers organized in lines to maintain service corridors .
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White UV-resistant capping connecting condensers and bushings, discreet and waterproof.
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Waterproof electrical boxes installed at each device for secure diagnosis .
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Release brackets hold units above water and snow accumulations.
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Systematic leak testing and commissioning with pressure/temperature recording to document initial performance.
AirGreen Best Practices for Montreal Roofs
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Plan slopes and drains : Ensure the unit stays out of main runoff areas.
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Snow clearances : provide a base height that prevents partial burial during storms.
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UV protection : use approved roofing envelope materials and inspect penetration collars.
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Vibrations : combine pads, controlled clamping and pipe routing with anti-vibration loops.
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Short trajectories : reduce unnecessary refrigeration lengths to maintain seasonal efficiency .
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Documentation : Deliver route diagrams, serial numbers, commissioning values and HVAC maintenance schedule.
Recommended maintenance
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Annually : cleaning of coils, checking of electrical terminals, condensate test, inspection of insulation and capping.
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In both seasons : checking the filters of the indoor units, washing the tanks, checking the fans.
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After major weather events : courtesy visit to ensure the integrity of supports and clearances.
Grants and administrative support
Several Fujitsu Energy Star -eligible wall-mounted heat pumps meet the criteria of provincial and federal programs. We:
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validate the capacity and performance according to the configuration of the premises,
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prepare proof of purchase and commissioning ,
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guide the owner to file a compliant application, both in Montreal and in Laval , Longueuil , on the North Shore and the South Shore .
Result: comfort, discretion and long-term value
The chosen solution combines compactness, visual simplicity, and performance in cold climates. The building gains in comfort while controlling its operating costs. With rigorous implementation and a clear maintenance plan, the Fujitsu rooftop heat pump becomes a sustainable investment for both co-owners and building managers.
Why AirGreen
We work weekly on roofs in Greater Montreal . Our strengths: certified teams, strict compliance with RBQ standards, optimized refrigeration paths, and a results-oriented consulting approach. We handle technical preparation, installation, commissioning, and grant support, right up to the first maintenance cycle.