Two R-32 wall systems installed high on a brick facade: four-season comfort and exemplary integration
At AirGreen , we installed two Sharp wall-mounted heat pumps – ZU1 range (R-32) on the rear facade of a plex in Plateau-Mont-Royal, Montreal . The typical brick building and access via an alley require careful planning: working at height , specific masonry anchors, clearance management around a large sliding patio door and a side metal ladder/stairs . The result: a clean, quiet and durable installation, designed for both comfort and long-term maintenance.
Why the Sharp ZU1 (R-32) range for a Plateau plex
Sharp ZU1 wall-mounted heat pumps are an ideal solution for Montreal stacked dwellings:
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R-32 refrigerant : more efficient and lower GWP than R-410A, meeting new environmental requirements.
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High-efficiency inverter : fine modulation of capacity to maintain a stable temperature while reducing consumption.
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Extreme cold operation (depending on range capacity): reliable heating during Montreal winters.
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Low noise level : essential for backyards and narrow alleys.
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12k to 24k BTU range : can be scaled per apartment depending on the envelope and orientation.
In this project, the objective is twofold: to ensure the independent comfort of two dwellings and to reduce operating costs compared to old resistive systems or seasonal air conditioners.
Site identification, sizing and preparation
Before any perforation, our team proceeds to:
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Structural verification of the load-bearing brick and search for optimal joints for anchoring.
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Calculation of refrigerated lengths and the best covered route to avoid unsightly diagonal descents.
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Height selection : the two condensers are installed on wall brackets approximately 2.4–2.8 m from the floor. This elevation:
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protects against accumulations of snow and debris ;
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frees up space around the patio door;
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facilitates air circulation and limits the risk of vandalism.
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Drainage plan : directing the defrost runoff to a permeable area of the yard, without running off onto the glazing or the driveway.
Installation of consoles and anchors suitable for brick
The galvanized brackets are fixed with mechanical anchors sized for the dynamic load of the compressors. We add:
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spacers to compensate for any possible out-of-plumb cladding;
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anti-vibration pads under the frames to limit the transmission of vibrations into the masonry;
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anti-corrosion treatment of exposed cuts and hardware.
Each unit maintains standard clearances at the front and sides, essential for airflow and defrost cycles.
Aesthetic drilling, sealing and covering
The wall-to-wall passage is made via an insulated through-hole . We implement:
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sleeves and vapor barriers to eliminate any thermal bridges;
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interior/exterior sealing with masonry-compatible mastic;
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rigid beige/grey capping laid vertically then horizontally , to discreetly join the penetrations under the window upstairs.
This cover protects the insulated refrigeration lines , the communication cable and the power cable from UV and weather, visually aligning with the brick joints.
Refrigeration connections and leak testing
Our certified technicians carry out:
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calibrated flaring (flaring torques with a torque meter);
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deep vacuum draw to a stable target pressure;
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the holding test and release of R-32 refrigerant from the outdoor unit;
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checking for overheating/subcooling and adjusting inverter parameters in test mode.
This methodology guarantees clean lines , a sealed circuit , and therefore maximum efficiency throughout the seasons.
Power supply and safety
Each unit has its own dedicated circuit from the interior panel, with external protection and disconnection within easy reach for maintenance. The routing follows the enclosure for a clean finish and simplified maintenance. Grounding and compliance with conductor gauges are validated according to the Quebec Electrical Code .
Condensate and frost management: a priority in urban environments
To preserve the masonry and rear circulation:
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Gravity drain from evaporation pans, directed away from traffic areas.
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Sufficient vertical clearance under each unit to prevent ice buildup during defrosting.
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Operating advice : clear snow from the base of the wall, keep the space clear in front of the grilles.
Daily comfort and energy savings
Both apartments now benefit from:
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rapid and uniform cooling in summer, even during hot episodes on the urban heat island;
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stable heating at a controlled cost during the winter, thanks to the Inverter compressor and the extreme cold performance of the ZU1 range ;
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reduced noise level : choice of anti-vibration mounts and fan settings adapted to neighborhood nights.
On the bill, the inverter modulation and the efficiency of R-32 translate into substantial savings compared to direct electric heating.
HVAC Maintenance: Our Plan to Maintain Performance
To maintain the performance of wall-mounted heat pumps in alleyways:
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Clean the internal filters every 1–2 months during the season.
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Annual inspection : external exchanger, tightening of connections, insulation test and control of refrigeration parameters.
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Clearing climbing vegetation around the hood to maintain ventilation.
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Check the cowling after freeze/thaw cycles; preventative tightening if necessary.
AirGreen offers maintenance plans tailored to plexes, condominiums and small rental buildings in Greater Montreal .
Construction site challenges and AirGreen solutions
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Old brick facade : choice of suitable anchors and distribution of loads on long consoles to avoid tearing.
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Access via narrow alley : delivery in slots, light scaffolding and harness for working at height without disturbing neighbors.
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Underlying French window : installation of cantilevered units with secure vertical clearance, to preserve light and circulation.
These solutions ensure a solid, aesthetic and safe result without compromising on performance.
Grants and Eligibility
High-efficiency R-32 systems like the Sharp ZU1 range are generally eligible for energy efficiency support programs in Quebec. We support our clients to document the installation , provide the necessary specifications and optimize the demand according to the configuration (apartment, condominium, house).
What you gain with AirGreen
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Local HVAC expertise : mastery of the specificities of Montreal plexes, heights and brick facades.
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Careful aesthetics : discreet capping , linear paths, aligned consoles.
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Strict compliance : RBQ/CSA standards, complete testing and submission of an installation report .
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After-sales service : rapid support in Montreal, Laval, Longueuil, North Shore and South Shore .
For a similar project – a wall-mounted heat pump for an apartment, condo or plex – our team designs a custom size and an HVAC installation designed to last.