A clean and durable upgrade for a brick duplex in the heart of Montreal
Project background
At AirGreen , we are modernizing the comfort of a typical brick duplex in Rosemont–La Petite-Patrie . The goal: to provide reliable, quiet, and energy-efficient heating and air conditioning for two separate dwellings, while respecting the aesthetics of a facade visible from the street. We are installing two Sharp (R-32) outdoor units on wall brackets , each dedicated to a wall-mounted indoor head ( single-zone configuration per apartment). The chosen solution guarantees independent control, reduced operating costs, and simplified maintenance.
What we install — in brief
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Machine type: single-zone wall-mounted heat pump (mini-split).
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Brand: Sharp , new generation R-32 .
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Configuration: 2 separate systems (one per dwelling).
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Supports: galvanized wall brackets with silent blocks.
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Route: horizontal section at the bottom of the wall then vertical climb over ~6–7 m up to the openings towards the interior heads.
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Finish: rigid brown capping coordinated with the brick; electrical conduits in metal sheath at the bottom, then dedicated sheath up to the circuit breaker.
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Drainage: gravity (controlled slope, discreet outlet).
HVAC Installation Details: Line Cleanliness, Performance, and Compliance
Neat and durable exterior layout
We mount the condensers on wall brackets to free the ground, prevent snow accumulation, and facilitate snow removal—a crucial point in Montreal . The center distances and seals are calculated based on the solid brick and joints, with mechanical anchors, sealing washers, and polyurethane sealant. The silent blocks absorb micro-vibrations for quiet operation indoors and in the yard.
Link paths: efficiency and aesthetics
Vertical brown capping centralizes refrigerant lines and communication cables. We start horizontally at ~40–50 cm from the ground — in a protective duct — then rise in a column for ~6–7 m. This choice:
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Reduces facade drilling ;
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Uniforms the aesthetics on the red brick;
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Simplifies subsequent HVAC maintenance (clear access, immediate location).
Bends are made to minimum radii to preserve the integrity of the R-32 insulated copper. Each fitting is nitrogen brazed , with a deep vacuum (<500 microns) and leak tested with dry nitrogen. We balance line lengths (approximately 10–12 m per system) to stay within the manufacturer's optimal ranges and limit refrigerant top-up.
Electrical and drainage management
To the right of the facade, a service mast and a meter are present: we coordinate the dedicated circuit and the exterior disconnect box according to the Quebec Electrical Code . The cables run in a low metal sheath, then join each unit in the capping. The condensate drain is gravity- fed, with controlled slopes and exit outside the passage area. The absence of a condensate pump reduces noise, maintenance and the risk of breakdown.
Drilling, sealing and vapor barrier
Each penetration includes a sheath , outward slope and flashing . Inside, we restore the air/vapor barrier , an essential detail for the envelope of Montreal plexes. The penetrations are insulated to prevent thermal bridges and condensation.
Why Sharp (R-32) for a Rosemont plex?
Yield and extreme cold
The new generation R-32 improves COP and cold weather heating capacity, while reducing the environmental footprint compared to R-410A. For a duplex, this translates to:
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Energy savings in winter and summer;
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Stable comfort down to substantial negative temperatures;
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Discreet exterior noise level , appreciated by neighbors.
Modularity by housing
Two independent systems simplify cost allocation and give each occupant control over their comfort. In the event of maintenance, one zone remains operational .
Eligibility for programs
High-performance R-32 wall-mounted heat pumps may be eligible for provincial subsidies when seasonal performance and cold weather operating criteria are met. At AirGreen, we guide our clients in Montreal , Laval , Longueuil , North Shore and South Shore to build applications and validate eligibility .
Results: clean facade, increased comfort, controlled bill
What the customer gets today
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Clean facade : a vertical column , stained on stain , which respects the architecture of the building;
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4-season comfort : high-performance heat pump for off-season heating and hot summers;
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Simplified maintenance : clear access to units, openable capping , clearly identified components;
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Reduced noise : rigid mounting + silent blocks = limited transmissions;
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Predictable costs : optimized consumption thanks to R-32 and inverter regulation.
AirGreen best practices (checklist)
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Calculation of refrigeration load and verification of lengths;
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Nitrogen brazing , leak testing , documented deep vacuum ;
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Initial settings (flow rates, shutters, instructions) and occupant training ;
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AirGreen labor warranty and HVAC maintenance reminders.
HVAC Operation and Maintenance Tips
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Leave the ventilation running continuously at low speed for a uniform temperature.
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Clean the internal pre-filter every 4 to 6 weeks during the summer.
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Clear 30–40 cm around outdoor units in winter.
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Plan annual maintenance (inspection, pressures, tightening, cleaning of exchangers).
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Avoid forcing Auto mode during mid-season: prefer Hot or Cold as needed.
For a similar project in Greater Montreal
We design aesthetic, compliant and sustainable HVAC systems for plexes, condos and houses. Whether you are in Montreal , Laval , Longueuil , on the North Shore or the South Shore , our team offers the right size , the right line route and commissioning to the AirGreen standard.