A targeted comfort upgrade for a Montreal home: R-32 efficiency, careful back-to-back installation, rigorous commissioning and maintenance advice for lasting savings.
The context: a clear need for stable comfort, summer and winter
In Rosemont–La Petite-Patrie, we are working on a home with light-painted walls where the main room overheats in the summer and remains cool in the inter-seasons. The client's goal is simple: to achieve consistent comfort , controlled consumption , and a discreet installation that integrates without major work. We recommend a latest-generation Gree wall-mounted heat pump with R-32 refrigerant , a relevant solution for Montreal apartments and plexes thanks to its small footprint, fine modulation, and cooling performance.
Why Gree (R-32) for this type of housing
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High Seasonal Performance : Gree's new R-32 ranges offer advantageous COP/SEER and continuous modulation to keep up with the variable loads of an urban home.
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R-32 : Better specific refrigeration capacity and lower GWP than R-410A, which helps reduce the environmental footprint while improving efficiency.
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Careful acoustics : the blowing profile and the inverter compressor limit noise pollution, an essential factor in living spaces.
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Compatibility with assistance programs : depending on the configuration and certified ratings, this type of equipment may be eligible for assistance . We systematically validate eligibility during submission for Montreal, Laval , Longueuil , North Shore and South Shore .
Sizing and capacity selection
Before any installation, we analyze: surface area, insulation, orientation, air infiltration and actual use. In this case (main closed room + adjoining area), a capacity of 9,000 to 12,000 BTU/h is generally suitable. We favor modulation : a slightly undersized but efficient unit at low speed provides more stable comfort and better dehumidification than an oversized model that cycles.
Site preparation and interior layout
The wall head is installed at the top , near the corner of the room, to promote transverse airflow .
Key points of our implementation:
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Clearances respected above and laterally for optimal air exchange.
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Wall bracket anchored in the structure, checked for level.
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Discreet drilling management : the entire refrigeration lines + power cable + gravity drain pass through the rear right of the unit , with clean and watertight sealing to prevent any infiltration of air and humidity.
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Compliant drain slope : the outlet is positioned to drain condensate naturally to the outside, eliminating the need for a pump in this context.
Link path: optimized back-to-back configuration
The picture illustrates a back-to-back pose: the wall crossing is done behind the head, reducing the length of connections to approximately 1 to 1.5 m . Advantages:
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Minimized heat losses and reduced load drop .
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Aesthetics : no visible interior cover, only a discreet sealing finish remains.
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Reliability : fewer solders and bends = fewer potential leak points.
Outside (not visible here), we fix the condenser on galvanized brackets or raised slab , depending on the facade and clearances. The lines are continuously insulated , protected by a UV cover, and defrosting is taken into account (rear/side clearance, free flow).
Electricity and protections
We install an external disconnect switch near the condenser and a dedicated breaker at the panel, in accordance with code. The communication/power cable is run in the same conduit as the lines for a clean finish. Grounding is verified and tightening is torque-controlled.
Meticulous commissioning
Our steps, without compromise:
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Nitrogen leak test .
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Deep vacuum with digital vacuum gauge: ≤ 500 microns stabilized.
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Opening the valves and checking for any pressure build-up.
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Start-up in cooling and heating modes: supply/return temperature readings, intensity, pressure, and temperature difference (Delta T) to validate performance.
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Calibration of the sweeper and explanation of the modes to the user (Auto, Dry, Heat, Eco, programming).
Result obtained
From the moment it is put into operation, the Gree unit provides a uniform blowing , perceptible at low speed without drafts. The noise level remains contained, ideal for a living room, an office or a bedroom in Rosemont. In air conditioning mode, dehumidification stabilizes the humidity during heavy days; in the off-season, the heat pump provides an economical supplement compared to electric baseboards.
Good usage practices
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Filter : rinse with lukewarm water every 4 to 8 weeks (depending on dust and animals).
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Dry mode during humidity peaks to improve comfort without overcooling.
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Reasonable instructions : 23-24°C in summer, 20-21°C in winter.
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Doors left ajar to aid diffusion if the room leads to a corridor or adjoining room.
AirGreen Preventive HVAC Maintenance
To ensure longevity and effectiveness:
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Annual inspection : in-depth cleaning of the evaporator (bio-cleaning), the fan and the condensate tray, checking the drain, electrical connections and the condition of the insulation.
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Refrigeration control : visual inspection of the covers and performance test.
Regular HVAC maintenance maintains efficiency and prevents odors associated with biofilms.
Pitfalls to avoid (feedback from Montreal, Laval, Longueuil, North Shore, South Shore)
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Oversize the device: short cycles, discomfort and increased bill.
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Install too close to a tight corner without clearance: air recirculation and noise.
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Neglecting the slope of the drain : risks of internal flows.
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Ignoring the outside environment : condenser too low in a snowy driveway, airflow blocked by a terrace, etc.
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Forget about UV protection for insulation and facade covers.
Deadlines and coordination
A back-to-back wall unit installation is generally completed in one day , including drilling, connections, testing and user training. For co-ownerships, we support the client in obtaining union authorizations (facade passage, color of the covers) to ensure compliance.
Why AirGreen for your HVAC system?
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Greater Montreal specialists : mastery of local realities (brick facades, exterior staircases, alleys, flat roofs).
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Selection of recent equipment (R-32/R-454B) aligned with current best practices.
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Rigorous commissioning and responsive after-sales service .
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Grant support : we verify eligibility and prepare the necessary documents when applicable.
And what next?
If you are considering covering other areas of the home or adding a MultiZone heat pump , we size the whole unit (2 to 5 heads) taking into account the connection lengths, heights and defrosting rules. Our priority: lasting comfort , careful aesthetics and a tangible return on investment .
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