Installation of a Sharp Eco Inverter (wall-mounted heat pump) on a flat roof in Villeray–Saint-Michel–Parc-Extension
AirGreen installs a Sharp Eco Inverter wall-mounted heat pump on a flat roof in Villeray: rails and pads to protect the membrane, optimized air clearances and rigorous commissioning for four-season comfort.
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A flat roof installation, designed for durability and service
The AirGreen method: performance, roof safety and efficiency in extreme cold
In the Villeray–Saint-Michel–Parc-Extension sector of Montreal, we installed a Sharp Eco Inverter wall-mounted heat pump on a flat roof typical of Montreal plexes. This type of installation requires a combination of respect for the membrane , load management , air clearances and impeccable service access . This is exactly what we do every day at AirGreen , throughout Montreal, Laval, Longueuil, on the North Shore and the South Shore .
The equipment: Sharp, efficient and silent
The Sharp Eco Inverter with R-32 refrigerant is a modern wall-mounted heat pump , renowned for its high seasonal efficiency and stable heating during cold peaks. The DC inverter compressor precisely modulates power to maintain the temperature smoothly and limit consumption.
In terms of comfort, the condenser's acoustic architecture and electronic control ensure a low noise level , appreciated in Montreal's densely populated areas. Depending on the interior head configuration chosen, Sharp Plasmacluster™ technology contributes to better air quality .
Rooftop installation: principles and technical choices
Installing a wall-mounted heat pump on a flat roof isn't a simple translation of the ground-mounted installation. We apply specific principles:
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Membrane preservation : the condenser is placed on an aluminum frame resting on distribution rails . Under the rails, we use high-density insulating pads to diffuse the charge and eliminate any pressure points on the membrane.
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Usable height : the elevation of the chassis creates a sufficient air plenum for suction and prevents the accumulation of water, ice or gravel under the device.
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Discharge orientation : we orient the unit to avoid any recirculation of hot air towards parapets, low walls or vent outlets, which preserves efficiency in both summer and winter.
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Service access : front and side clearance optimized to allow maintenance operations (cleaning, pressure measurements, diagnostics).
Refrigerant and electrical path: cleanliness and robustness
The route of the lines is a major factor in performance:
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UV Insulated Refrigerant Lines : UV-resistant closed-cell insulation, capped and neatly tied to prevent wind lift.
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Controlled service loop **: a line reserve is left to facilitate future interventions without mechanical constraints on the expanders.
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Roof passage : sealed crossing with a dedicated box/flashing and membrane-compatible sealant, to prevent any infiltration.
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Power supply : accessible external disconnection near the condenser, wiring sized according to the nominal current and secure routing to resist UV and thermal cycles.
Condensate management: solutions adapted to the roof
A wall-mounted heat pump releases little water to the condenser in summer, but winter frost management remains essential:
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The raised frame and free space under the unit allow natural defrosting without direct contact with the membrane.
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If necessary (special drainage configuration), we plan a flow directed towards a traffic-free area, in order to avoid ice patches.
Commissioning: AirGreen quality control
Our commissioning protocols guarantee performance from day one:
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Nitrogen leak tests with stabilization.
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Deep vacuum controlled by micronmeter , until lasting stabilization.
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Complete electrical checks : polarity, continuities, tightening torque, disconnection tests.
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Functional tests in cold and hot conditions: intensity, evaporation/condensation temperatures, delta-T and Inverter behavior.
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User settings : explanation of modes, setpoint deviations, filter maintenance and best practices for saving energy.
Flat roof specificities and challenges: how we managed them
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Wind and wind resistance : Rooftop appliances are exposed. We mechanically secure the frame to the rails, and the distributed mass prevents any lifting.
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Routes : to avoid any risk of snagging or water pockets , the line follows a short route , without sharp bends, and remains clear of maintenance points (drains, vents).
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Membrane protection : no sharp edges in contact. Insulating pads under rails protect elastomeric or bituminous membrane roofs and facilitate possible relocation without damage.
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Winter service : Access must not depend on an unstable ladder. We define a safe path and indicate to the owner which access points must be kept free of snow.
Customer results: comfort, efficiency and peace of mind
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Four-season comfort : efficient air conditioning in summer, efficient heating support in spring and autumn, or even in the middle of winter depending on the model's temperature range.
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Measurable reduction in consumption thanks to the inverter compressor and optimization of line lengths.
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Silence : the distance from the ground and the damping of the rails reduce the transmission of vibrations to the structure.
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Preserved aesthetics : no footprint on the ground or on the facade; from the street, the equipment remains discreet .
AirGreen Best Practices for Flat Roof Installation
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Always distribute the load (rails + high-density pads): this is the key to protecting the membrane.
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Provide air clearances greater than the minimum when the appliance is surrounded by roof elements (parapets, ducts, chimneys).
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Use UV insulators and stainless steel clamps for long-term durability.
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Systematize external disconnection and clear markers (circuit labeling) to facilitate any intervention.
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Check the condition of the pads , seals and fasteners at each maintenance visit.
Recommended HVAC maintenance
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Clean the inner head filters every 4–8 weeks during use.
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Annual inspection by our technicians: pressures, temperatures, intensities, tightening, condition of the insulation and roof passages.
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Clear the area around the condenser (leaves, objects) and check defrosting in winter.
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Never defrost the appliance mechanically : the integrated defrost cycle takes care of it.
Grants and Eligibility
Depending on the configuration and certified performance of the chosen indoor head, this type of wall-mounted heat pump may be eligible for energy efficiency programs available in Quebec. We assist our clients in verifying criteria , preparing files and optimizing the energy-efficient solution best suited to their home.
Why choose AirGreen for your flat roof installation?
We design each project as a mini-engineering project : calculation of load on the membrane, choice of rails and pads , orientation, optimal line length, service strategy and safety . Our promise: a durable, efficient and easy-to-maintain HVAC installation , delivered turnkey by a local team that understands the climatic realities of Greater Montreal.
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).