Careful commissioning for demanding Montreal winters
At AirGreen , we designed an HVAC installation that combines performance, discretion and durability in a plex in Mercier–Hochelaga-Maisonneuve . The client chose a Sharp wall-mounted heat pump (Eco Inverter range, R-32 refrigerant) , perfectly suited to the pace of urban life and the marked temperature variations of Montreal .
The customer need, simple and clear: 4-season comfort and controlled bills
The accommodation, exposed to the river winds and the summer heatwave, required a reversible system capable of ensuring:
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stable heating in winter down to very low temperatures;
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precise and quiet air conditioning in summer;
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measured consumption , compatible with the subsidy programs in force in Greater Montreal ( Montreal, Laval, Longueuil, North Shore, South Shore ).
After load calculations (insulation, windows, orientation), we selected a configuration ≈ 18,000 BTU covering the open-plan living room, the kitchen and a distribution corridor to the bedrooms. The power margin takes into account winter losses without oversizing the equipment.
Exterior integration: robust, safe and designed for snow
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Raised structural support in galvanized steel: it protects the unit from snow accumulations and facilitates maintenance.
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High-density anti-vibration pads under the support points: they reduce the transmission of structure-borne noise to the floors and guardrail.
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Clearances maintained around the fan and at the rear to ensure the required airflow in heating and defrosting mode.
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Power supply under duct, connected to a compliant external disconnect switch ; separate control wiring to avoid interference.
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Insulated refrigeration line , short and clean route to the interior head; curvature radii respected to preserve heat exchange.
This positioning protects the equipment from falling ice and limits the suction of recycled air under the balcony, a critical point for performance in heat pump mode.
Commissioning: the AirGreen difference
The photo shows our manifold bench connected during commissioning. This often-overlooked step is critical to longevity and performance.
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Nitrogen test : high pressure pressurization (typ. 350–400 psi depending on ambient temperature) and leak test by pressure drop and foaming liquid detection.
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Triple evacuation : deep vacuum to ≤ 300 microns , with nitrogen rest/break between cycles to remove residual moisture.
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Opening of the R-32 fluid of the outdoor unit, controlled purging and stabilization.
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Functional measurements : current , superheat and subcooling readings; control of supply/return temperatures and delta-T.
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User settings : Auto/Heat/Cool modes, fan speed, shutter orientation, night scenarios.
The result: a quiet heat pump , equally at home in autumn drizzle or at -20°C, and ready to offer significant savings compared to electric baseboard heaters.
Inside: discreet comfort and even diffusion
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Wall-mounted head positioned to sweep the main living area, with air path avoiding direct currents on the sofa.
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Gravity condensate management , controlled slope and frost-proof outlet.
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Finished with matching capping for a clean and durable integration.
Adjusting the shutters and using Dry mode in mid-season improves the feeling by reducing humidity without overcooling the room.
Why the Sharp Eco Inverter range is attractive in urban areas
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R-32 : better GWP than R-410A and very good heat exchange, therefore higher efficiency.
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Inverter compressor : fine modulation, fewer on/off cycles, more silence and durability .
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Plasmacluster functions (ionic treatment): a welcome plus for indoor air quality .
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Easy maintenance : accessible filters, rapid diagnostics via codes and curves.
Grants and eligibility (depending on configuration)
The latest generation of high-efficiency wall-mounted heat pumps are generally eligible for financial support from Transition énergétique Québec and related programs (e.g., residential components applicable in Montreal, Laval, Longueuil, North Shore, South Shore ). Our team supports the customer: proof of purchase, performance characteristics, photos, AHRI numbers , forms and deadlines.
What we particularly monitored on this project
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Air recycling under the balcony: we have guaranteed sufficient front and side clearance to prevent the machine from re-inhaling its exhaust air, which would penalize capacity in the middle of winter.
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Vibrating bridges : pads + tightening to the recommended torque on the fixings to protect the wooden structure of the balcony.
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Electrical routing : clear separation of power/control, tightening of terminal blocks, checking of polarity/ground and circuit breaker rating.
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Frost management : base height and orientation which facilitate the flow of defrost water.
HVAC Operation and Maintenance Tips for the Homeowner
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Maintain a snow clearance of ± 45 cm around the unit and clear the grid after a snowdrift.
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Avoid winter covers : they trap moisture and accelerate corrosion.
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Vacuum filters every 4–6 weeks during heavy use and wash in warm water; replace periodically depending on use.
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Schedule annual HVAC maintenance : electrical check, coils, fans, condensate, operating pressures and parameter updates.
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In heat waves, prefer a stable setting rather than variations of 4–5°C; the inverter will modulate and consume less.
Measured benefits for the customer
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Consistent comfort throughout the living space and adjacent bedrooms.
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Lower consumption versus electric convectors, particularly visible from October to April.
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Silence in the evening thanks to controlled vibrations and night mode.
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Clean and durable aesthetics , compatible with the architecture of the sector's plexes.
AirGreen, your local partner in HoMa and throughout Greater Montreal
Our team masters the constraints of walkways, balconies, narrow alleys and mixed facades (brick/vinyl) typical of central districts. We intervene with the same rigor in Montreal , Laval , Longueuil , on the North Shore and the South Shore : thermal study, selection of equipment, installation, commissioning , and support for subsidies .
Planning an HVAC installation or equipment replacement? We offer quick technical visits and detailed quotes, with power and finish options (brackets, capping colors, snow protection).
Express FAQ
Is a wall-mounted heat pump enough to heat a 5 1/2?
Yes, if the housing is relatively open and the insulation is adequate. Accurate sizing (BTU/h load) remains essential to avoid under- or oversizing.
What if I want to air condition two bedrooms?
We can consider a MultiZone (two heads) or an optimization of the placement of the main head with programmed shutters; an on-site smoke test helps to visualize the actual diffusion.
What minimum maintenance?
Regular filter cleaning + annual HVAC maintenance by a certified technician is essential to maintain performance and the warranty.