Four-season comfort in a narrow stairwell: our step-by-step approach
The request is clear: to ensure efficient summer cooling and winter supplemental heating in a typical Rosemont–La Petite-Patrie duplex, without encroaching on the living space. At AirGreen , we offer a clean, sustainable HVAC installation designed for Montreal realities. Here, we are installing a Sharp wall-mounted heat pump (recent generation with R-32 refrigerant ), positioned high above a window in a stairwell . This strategic placement maximizes air stratification and comfort distribution to the landings.
Customer context and performance objectives
The client lives in a Montreal plex with renovated gypsum walls , a narrow stairwell and high ceiling drops . The objectives:
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Keep the staircase and landings pleasant, while relieving adjacent rooms of heat peaks .
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Reduce the use of electrical backups in mid-season thanks to the heat pump function .
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Preserve aesthetics: no visible ducts , discreet casing on the outside, silence on the inside.
The wall-mounted heat pump is ideal here: compact size, high efficiency and fine modulation of the inverter compressor to precisely monitor the thermal load.
Why a Sharp R-32 wall unit?
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Proven reliability and quiet operation, essential in a busy area.
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R-32 : new generation refrigerant, more energy efficient and with reduced global warming potential compared to older generations.
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Extreme cold operating range adapted to the Montreal climate, useful for heating in the off-season and as a supplement in winter.
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Easy-access filters for simplified HVAC maintenance by occupants.
Note: in this type of space, a single, well-positioned wall-mounted head can create a beneficial chimney effect , circulating the air from top to bottom and homogenizing the temperature towards the upper floors.
Design and positioning: millimeter precision
Height and clearances. The unit is installed high under the ceiling , centered above the window frame . We respect the manufacturer's clearances for a free air intake and a blower that runs along the shaft without directly hitting the users—limiting the sensation of drafts.
Support and anchors. The wall plate is anchored to the studs with fasteners sized for shearing and tearing . A laser level ensures perfect plumb (essential for condensate drainage ).
Drilling. A single drilling of approximately 65 mm is made behind the device , with a continuous slope towards the outside for the gravity drain . The cross-section is sheathed to avoid any friction of the connections.
Refrigeration connections. The insulated copper tubes (outgoing/return) and the power/communication cable are gathered into a neat bundle , strapped, and then routed outside. Outside, they are protected by a UV-stable white cap , discreet on the facade.
Condensate management. The drain is installed by gravity , which eliminates the noise and maintenance of a pump. The slope is controlled throughout; a non-return loop prevents odors from rising.
Special features of a stairwell: controlling the airflow
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Blowing directed towards the volume and not towards the window: we adjust the angle of the shutters to create a laminar flow descending along the shaft.
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“Quiet” mode for quiet hours: the minimum speed reduces the noise level while maintaining the set temperature .
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Sensors : the head continuously measures the suction temperature; we set a setpoint taking into account the rising heat from the stages.
Result: a reduced thermal gradient , more comfortable landings and a lower load on other existing units or heaters.
Commissioning: rigor and traceability
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Flares calibrated to the torque, tightening torques respected.
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Nitrogen leak test , then deep vacuum ( < 500 microns ) with stability control.
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Opening of the fluid , checking of pressures , overheating and subcooling according to the outside temperature.
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Acoustic test at progressive speeds , control of vibrations and resonances on the wall.
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Mode settings (Auto/Heat/Cold), automatic restart in the event of a power cut, and shutter sweeping .
Each step is documented to ensure sustainability and facilitate maintenance monitoring .
Recommended HVAC maintenance
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Clean filters every 2–3 months (more frequently during pollen season).
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Gentle disinfection of exchangers once per season—limits dust and allergens.
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Annual inspection by AirGreen: electrical check, drain , fasteners , and performance trends (air/air temperatures, intensity, pressures).
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Outside: ensure that the capping remains watertight and that the drain flow is free.
This simple HVAC maintenance maintains efficiency and extends lifespan .
Grants and local compliance
Recent generation R-32 wall-mounted heat pumps may be eligible for current Quebec programs (based on performance and operating temperature criteria). We verify eligibility lists , help gather parts and provide the necessary proof of installation . Our team is RBQ licensed and applies the electrical and HVAC standards in use in Greater Montreal (Montreal, Laval , Longueuil , North Shore , South Shore ).
Common pitfalls avoided by AirGreen
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Bad drain slope : source of leaks and odors → electronically controlled throughout the line.
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Insufficient anchoring in light partitions → search for studs , suitable metal anchors.
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Blowing on glazing : risk of stratification and fogging → optimized orientation of the shutters.
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Oversizing or undersizing : load calculation adapted to the stairwell and the areas served.
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Noise : choice of quiet operating range and anti-vibration pads .
Result: tangible comfort and preserved aesthetics
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Uniform temperature between the bottom and top of the stairs, even during heat waves .
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Controlled consumption thanks to the inverter and good sizing .
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Discreet integration: the unit blends into the decor; no visible cables .
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Easy access for maintenance: filters on the front, clean external cover.
The customer benefits from four-season comfort and enhanced property value through professional and traceable installation.
Practical advice for plex owners in Montreal
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In stairwells , aim for a high position with adequate clearances so that the jet covers the landings.
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Favor gravity drainage of condensate when the facade allows it.
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Think maintenance : clean filter = efficiency and silence .
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For buildings facing the street and the courtyard , anticipate the shortest connection path and the least visible capping .
What we support
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Technical visit , sizing and advice on the appropriate Sharp choice (usual capacities 9,000 to 24,000 BTU).
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Complete HVAC installation : drilling, connections, power supply, commissioning .
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Grant application (depending on eligibility) for Montreal, Laval , Longueuil , North Shore and South Shore .
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After-sales service and annual HVAC maintenance .
Are you looking for a wall-mounted heat pump that's as discreet as it is efficient for your apartment complex in Rosemont or its surrounding neighborhoods? AirGreen takes care of everything, with the quality and rigor that have made our reputation.
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