A clever installation in a bedroom at the corner of an exterior wall
In a typical duplex in Rosemont–La Petite-Patrie (Montreal) , our team installed a Gree wall-mounted heat pump above a closet, at the end of an exterior wall facing the backyard. This configuration allows for ideal air distribution toward the bed and hallway while keeping the clearances around doors and windows clear. The unit is installed at the top of the wall , approximately 2.3 m from the floor, which promotes uniform circulation and limits cold spots near the windows.
Here we favor a gravity route for condensate drainage: thanks to the available height and the immediate proximity of the wall facing outside, the drain crosses the wall with a continuous slope without an additional pump. The refrigerant connections (insulated copper + communication cable) follow the same drilling - sealed with air barrier mastic - and exit in an external chute to the condenser installed in the courtyard, on an anti-vibration slab protected from snowplows. Result: neat aesthetics , easy maintenance, and reduced risks of infiltration.
Why this layout works so well in urban areas
-
Optimized airflow : Above the closet, the blower projects the flow along the ceiling, which then descends gently. This avoids direct air currents on the bed and maintains uniform comfort .
-
Short connection distance : only 2 to 3 m between the inner and outer heads. Less pressure loss, higher efficiency and reduced installation time.
-
Safety on the finishes : the wooden moldings and the upper crosspiece of the windows are preserved; we carry out a clean 65 mm drilling with a sheath, then a watertight closure on the interior side to preserve the vapor barrier.
-
Acoustics : The choice of a wall overlooking a quiet courtyard and the installation of the condenser on silent blocks reduce reverberations. Indoors, the Gree head's low range remains almost inaudible at night.
Technical details of the HVAC installation
Sizing and capacity
For a room of 11 to 14 m² adjoining a corridor, the 9,000 to 12,000 BTU range covers the majority of needs. We choose a high-efficiency Gree inverter unit, capable of finely modulating according to the actual load. In heating, it maintains its capacity down to -25 °C , an asset for the Montreal climate.
Key points retained during sizing:
-
Envelope : double-glazed windows on the courtyard side, wooden frames in good condition; infiltration measured low once the joints have been redone.
-
Internal gains : moderate sunshine in the morning, few heat-generating devices.
-
Air continuity : non-airtight door, allowing the corridor to benefit from the air conditioning of the room without using a second head.
Refrigerant and electricity path
-
Drilling : wall penetration with a slight outward slope (≈ 5 mm) for condensate drainage. Sheath and internal collar for a clean finish.
-
Trunking : UV ivory white exterior casing, 90° elbow and low outlet towards the condenser. Stainless steel fixings.
-
Lines : 1/4–3/8 copper , high-density cellular insulation (UV-protected sleeves on the outside). Estimated total length: 2.6 m.
-
Drain : 5/8 vinyl pipe with backflow preventer and drip stop, outlet directed to a drainage point away from woodwork.
-
Power : Dedicated breaker at main panel, CSA sheathed outdoor cable to condenser proximity switch, then to unit cabinet.
Frost and snow management
The condenser is placed 30–35 cm from the finished floor , on a recycled polymer slab with anchors. A 60 cm clear area all around prevents snow accumulation. On the rear facade, the roof drain is located further away to avoid spilling onto the unit. Snow protection can be added if wind direction requires it.
Result for occupants: comfort, silence, savings
-
Four-season comfort : in heat mode, the regulation maintains a stable 21°C without drying the air; in summer, humidity is quickly lowered thanks to Dry mode on heavy days.
-
Controlled noise : the indoor head drops below ~20–22 dB(A) at night, the condenser operates at low frequency after reaching the set point.
-
Consumption under control : inverter modulation and short path limit losses; initial customer readings show a significant drop in summer kWh compared to an old window air conditioner.
-
Simplified HVAC maintenance : washable filter accessible from the front, coil treated to better resist urban dust, ample clearance around the outdoor unit for annual rinsing .
Grants and Eligibility
In Greater Montreal ( Montreal, Laval, Longueuil, North Shore, South Shore ), several programs encourage the installation of efficient wall-mounted heat pumps . Gree units with low consumption and capacity maintenance in cold weather are generally eligible based on the technical data sheet, the AHRI and low temperature performance. Our team supports customers on:
-
AHRI verification ,
-
preparation of proof of purchase and installation ,
-
the submission of grant applications ,
-
coordination with inspection if required.
Best practices that we systematically apply
1) Waterproofing and air barrier
Even the smallest hole in the envelope can cause condensation and energy loss. We install a sleeve, closed-cell foam, and elastomeric sealant to seal the hole, then a finishing acrylic seal on the inside.
2) Stain-free condensate management
Drain outlet with anti-drip tab to direct water away from the cladding. In winter, the pipe is insulated on the exposed portion to prevent freezing.
3) Respect for clearances
Inside, we maintain ≥ 10 cm of ceiling clearance and avoid backdrafts against blinds. Outside, rear and side clearances comply with the manufacturer's recommendations.
4) Anti-vibration
Silent blocks under the condenser and flexible elbows in the chute limit the transmission of structure waves to the night rooms.
5) Instrumented commissioning
-
Vacuum draw < 300 microns and resistance test.
-
Weighing of fluid if addition required according to length.
-
Measurements : delta-T, compressor current, external static pressure, error code verification.
What this changes in the daily lives of owners
From the first week, the occupants noticed:
-
a more stable room temperature at night;
-
less humidity during stormy episodes;
-
a perceived silence superior to their old window air conditioner;
-
a feeling of clean air thanks to the pre-filter and automatic sweeping which gently circulates the space.
They also appreciate the aesthetics : the device, grouped in the upper corner, frees up the bay window and highlights the renovated wooden joinery. The exterior chute, aligned with the moldings, remains almost invisible from the courtyard.
AirGreen: rigor, site cleanliness, respect for deadlines
Our teams operate throughout Montreal, Laval, Longueuil, on the North Shore and the South Shore , with the same requirements: load analysis, choice of location, clean and safe HVAC installation , documented commissioning , and clear explanations to the customer. We also offer HVAC maintenance plans : in-depth cleaning of the evaporator, connection checks, defrost tests, drain rectification. This annual maintenance extends the life of the equipment and preserves its performance.
Practical tips for a room like this
-
Program 23°C day / 21°C night to avoid short cycles.
-
Leave the door ajar when the next room needs to benefit from conditioning.
-
Clean filters every 6–8 weeks during the season.
-
Clear 60 cm around the condenser before winter; check after each storm.
-
Avoid blinds placed over the blower outlet so as not to disturb the probe.