Installation of a Fujitsu Airstage wall-mounted heat pump in Plateau-Mont-Royal
AirGreen installs a Fujitsu Airstage on a flat roof in Plateau-Mont-Royal: raised support, protected connections, gravity drain and rigorous commissioning. HVAC installation and maintenance throughout Greater Montreal.
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A flat roof installation that combines performance, silence and reliability
At AirGreen , we adapt each HVAC installation to Montreal's architecture. In this Plateau-Mont-Royal plex, we installed a Fujitsu Airstage wall-mounted heat pump with a condenser installed on a flat roof . The goal: to guarantee four-season comfort, easy maintenance access, and maximum longevity despite exposure to the climate.
Why the Airstage range meets the needs of a Montreal plex
Fujitsu's Airstage family is renowned for its fine modulation, reliable components, and cold resistance. In a typical plex configuration:
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interior diffusion by one or more wall heads effectively covers living rooms;
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the rooftop condenser frees up the backyard, respects the co-ownership and reduces noise transmission;
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Inverter performance lowers consumption compared to electric baseboards.
Our installation method: clean, durable, compliant
Raised support and membrane protection
We place the outdoor unit on a galvanized trestle on wooden foundations resting on the gravel layer. Anti-vibration pads limit resonances. The support points are distributed to protect the roof's waterproofing membrane and facilitate water drainage.
Clearances and air circulation
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Respect the clearances at the front and rear for effective defrosting in winter.
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Orientation of the propeller away from obstacles (skylights, parapets) in order to avoid air recycling .
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Route of connections on the roof kept as short as possible to preserve seasonal efficiency.
Refrigeration connections and power supply
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Refrigeration lines exit under black insulated sheath to the parapet, then protected vertical descent.
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Total length of approximately 8 to 12 meters , calibrated as needed with additional load to stay within the Fujitsu performance window.
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Protected communication cable and dedicated power supply ; double-pole circuit breaker and disconnection means near the unit, in accordance with RBQ/CSA requirements.
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Defrost drain extended and directed to a drainage area, away from traffic.
Drilling, sealing and finishing
Inside, the wall heads are fixed at the optimal height (≈2.10–2.20 m). We make a clean drilling with a gravity slope for condensates, installation of a sheath and vapor barrier seal . The seals ensure the airtightness of the envelope and limit cold air bridges.
Vacuuming, testing and configuration
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Deep vacuum , stabilization and leak testing.
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Checking delta-T in heating/cooling, intensity, and balancing fan speeds.
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Adjust the sweep to avoid direct airflow onto occupants and optimize stratification.
Result: constant comfort and simplified maintenance access
Comfort and savings
The heat pump maintains a stable temperature with low noise. Inverter cycles reduce peak consumption and energy bills compared to all-electric heating.
Access and maintenance
The rooftop location provides safe technical access without disturbing occupants. We schedule annual HVAC maintenance : coil cleaning, leak testing, electrical inspection, refrigeration measurements, and adjustments.
Winter on a flat roof: our attentions
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Cleared free for defrosting ;
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Routing of water discharge outside passage areas;
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Seasonal checks of the fixing and routing of the connections after freezing/thawing episodes.
Sizing and interior deployment
Capacity and distribution
For a plex dwelling in the Plateau, the range of 9,000 to 18,000 BTU/h per person covers most rooms. We always validate the thermal load (orientation, glazing, sealing) to avoid over- or undersizing.
Air quality and humidity
In summer, aiming for 45–50% RH ensures comfort and material preservation. Dedicated drying modes prevent overcooling, especially in open areas.
Grants and administrative compliance
Depending on the chosen configuration and the approved performance, the solution may be eligible for active programs. We assist with the verification of criteria (including Energy Star and cold resistance) and the preparation of parts (detailed invoices, serial numbers, compliant photos). Our coverage extends to Montreal, Laval, Longueuil, the North Shore and the South Shore .
What sets AirGreen apart
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Precise advice, clean HVAC installation , complete documentation;
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Strict compliance with standards, roof protection and durable finishes;
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Responsive after-sales service on Fujitsu , Midea , Gree , Sharp , Zephyr and other brands in our offer.
Plateau-Mont-Royal Project Review
The client benefits from four-season comfort , a clear backyard, and a system designed to last. The Fujitsu Airstage condenser on a flat roof combines easy maintenance, performance, and acoustic discretion—a solution perfectly suited to typical Montreal buildings.
The job tools
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
How the job unfolds
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
What we check on a job like this one
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
The right pages, at the right time
Four statements: true or false?
It all comes down to details you have just seen.
1. In heating mode, the outdoor unit can produce water.
During defrost cycles. That water must drain away without forming ice.
2. You pick the capacity with a simple square-footage rule.
Windows, insulation, orientation and how the room is used all count. Capacity is chosen on site.
3. A multi-zone connects several indoor heads to a single condenser.
One head per room, all on the same condenser. Each room keeps its own temperature.
4. The disconnect can sit behind the patio furniture.
It must stay accessible: it is what shuts the unit off for service.
0 / 4 right answers
What people ask us about this kind of work
Does a wall-mounted heat pump heat in winter?
Wall-mounted or multi-zone: how do I choose?
Where does the outdoor unit go?
Are there grants?
Do I need a permit?
How cold can it heat?
How much can I save?
How is the LogisVert assistance calculated?
Is it noisy?
The outdoor unit is covered in ice: is that normal?
Does AirGreen hold the required licences?
Is the estimate free?
No question matches. Write to us: we answer.
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).