Two GREE condensers on wall brackets: a robust and energy-efficient solution for a Montreal duplex
At AirGreen , we have just completed the HVAC installation of two GREE R32 series systems on the rear facade of a duplex in Rosemont–La Petite-Patrie . The client's goal: to provide four-season comfort to each unit, reduce operating costs, and preserve an unobstructed exterior, vulnerable to snow accumulation in winter. The result: two independent wall-mounted heat pumps , mounted on galvanized brackets above ground, neatly connected, and ready to face Montreal winters.
Building context and client needs
This plex, typical of the area, has a narrow backyard and a plastered foundation wall . The owners wanted:
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Two stand-alone systems (one per floor) for independent billing and control;
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A location outside the passageway in order to conserve floor space;
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Quiet and reliable operation in extreme cold ;
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Careful aesthetic integration , compatible with seasonal maintenance.
GREE's R32 series meets these criteria: low GWP refrigerant , inverter compressor, heating down to −25°C , high seasonal efficiency (Energy Star depending on configuration), and wide compatibility with modern wall-mounted heads (Livo/Vireo/Pular ranges, etc.).
Technical choice: two simple systems rather than a multi-zone system
In many cases, a multi-zone system may seem logical. Here, the AirGreen analysis favored two single capacitors for each stage:
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Increased redundancy : if one system stops, the other continues to provide comfort.
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Reduced line lengths : crossings are made almost back-to-back , which improves efficiency and simplifies refrigerant charging.
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Separate maintenance : each unit schedules its HVAC maintenance without immobilizing the other.
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Optimized overall cost : fewer accessories and complex refrigeration lanyards.
Outdoor installation: height, clearances and snow management
The two GREE condensers are mounted on sturdy wall brackets , with anti-vibration pads . This configuration:
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Maintains a ground clearance of approximately 60–75 cm , ideal for staying above snow banks and promoting frost runoff in defrost mode;
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Prevents the accumulation of leaves and debris in the fins;
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Clear the passage area near the back door and the small wooden staircase;
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Makes units accessible for maintenance (low pressure washing, connection inspection, fan check).
We strictly respect the minimum distances between units to avoid recirculating hot air in winter and to guarantee the necessary renewal rate for the condenser. An external electrical disconnect switch is installed between the two units for isolation and safety during work.
Refrigeration process and finishes: cleanliness and durability
The refrigeration connection and wiring pass through sealed wall penetrations and then run through UV-resistant black capping . Advantages:
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Mechanical protection of lines and insulation;
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Mastered aesthetics on the white plastered wall;
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Easy maintenance for any future intervention.
The condensate drains of the indoor units are configured to flow gravity-driven towards the outside when the architecture allows it, which avoids the addition of a pump (noise, maintenance). Indoors, the installation of the wall-mounted heads aims for uniform diffusion in the living areas, while respecting the clearances around the lintels and corners.
Expected performance and everyday comfort
GREE wall-mounted heat pumps (R-32) are distinguished by:
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Inverter compressor to finely modulate power: stable comfort, longer cycles, reduced bill ;
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High seasonal efficiency (SEER/HSPF depending on the head chosen), suitable for subsidy programs ;
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Reliable heating down to −25°C , relevant for Greater Montreal ;
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Quiet operation : low noise levels inside and dampened vibrations outside thanks to the supports.
Each apartment has an independent thermostat/controller . Occupants can therefore adjust the temperature to suit their needs: cooler nights upstairs, gentle maintenance on the ground floor, eco mode during the day.
Key steps in AirGreen installation
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Technical pre-visit : identification of partitions, electrical panels and choice of locations.
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Precise drilling with bulkheads and exterior sealing (mastic suitable for freeze/thaw cycles).
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Installation of anchor brackets on masonry and checking of flatness .
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Bending and brazing of lines (nitrogen procedure), installation of valves , deep vacuum , leak testing .
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Electrical connection (dedicated circuit breakers, compliant rating), installation of the disconnector and communication links.
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Commissioning : weight/subcooling charge according to GREE guidelines, functional checks.
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Delivery to the customer : usage advice, HVAC maintenance schedule, winter instructions (snow removal, defrosting).
Construction site challenges and solutions provided
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Basement window and narrow walkway: We centered the units between the opening and the stairs to keep exits clear and prevent backflow toward the window.
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Defrost management : the elevation on brackets and the slight outward slope prevent water from stagnating against the foundation.
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Line protection : choice of a contrasting dark capping , more discreet under the terrace, and UV collars for long-term durability.
Recommended maintenance for longevity
An AirGreen annual maintenance plan includes:
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Cleaning of indoor unit filters and gentle desludging of coils;
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Checking the electrical terminals , the disconnector , and measuring parameters (pressure/temperature);
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Checking the supports , the anti-theft pin of the brackets and the plumb line ;
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Inspection of cappings and sealing of crossings;
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Recommendations for use during cold weather (clearing of units, no aggressive snow removal on the fins).
Grants and Eligibility
Depending on the configuration chosen ( high-efficiency heads, Energy Star certification, heating performance in extreme cold), the project may be eligible for assistance offered in Greater Montreal (Montreal, Laval , Longueuil , North Shore , South Shore ). We support our clients in centralizing supporting documents (technical sheet, detailed invoice, proof of installation by a refrigeration contractor ).
AirGreen Best Practices for Outdoor Installations in Montreal
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Always raise wall-mounted condensers more than 45–60 cm from the floor.
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Anticipate 12–24 in. clearances at the rear and sides (depending on model) for optimal heat exchange .
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Avoid closed corners : risk of recirculated air and ice at the foot of the wall.
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Provide an accessible disconnect switch and a free drip line for defrosting.
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Plan short, straight paths : fewer losses , better efficiency.
Why entrust your project to AirGreen?
We are experts in installing GREE wall-mounted heat pumps in plex and Montreal homes : brick walls, plastered foundations, narrow yards, snow constraints. Our certified team delivers clean construction sites, compliant with the Building Code , with rigorous after-sales service and concrete operating advice to maintain performance.
Conclusion
This GREE R32 installation in Rosemont–La Petite-Patrie demonstrates the benefits of two autonomous systems for a duplex: customized comfort, energy efficiency , resilience and simplified maintenance . By choosing AirGreen, you are choosing an HVAC partner that thinks about durability , aesthetics and performance every day — in Montreal , Laval , Longueuil , on the North Shore and the South Shore .