Four-season comfort and a neat finish: a wall-mounted head above the windows, designed for quiet daily use
The customer context and the objective
In a typical plex in Mercier–Hochelaga-Maisonneuve , a homeowner wanted to air condition and heat the main living area without cluttering the space or detracting from the interior aesthetics. The priorities: silence , efficient heating in cold weather, and simple HVAC maintenance . We recommended aTosot wall-mounted heat pump —the residential brand of the Gree group—in a back-to-back configuration with the exterior to limit refrigeration lengths and maximize efficiency.
The interior head is installed at the top of the wall, centered above a set of windows , at an ideal height for even diffusion and to maintain the required clearances around blinds and cornices.
Why a Tosot wall-mounted heat pump in this home?
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Inverter technology : fine modulation of the compressor which reduces consumption peaks and noise levels, particularly important in Montreal plexes.
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R-32 refrigerant (recent Tosot ranges): better volumetric efficiency and lower global warming potential than R-410A; a choice aligned with current requirements.
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Efficient heating mode : the heat pump covers most of the mid-season and mild winter needs, relieving the burden on auxiliary electrical appliances.
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Perceived quality : smooth facade, touch control and motorized shutter ensure precise comfort control.
Interior installation: air diffusion and discreet integration
Positioning and clearances
We place the head in the center of the wall , away from the corners to avoid air recirculation. This position, combined with the adjustable shutter , allows the flow to be sent along the ceiling for optimal air mixing without direct air currents on the occupants.
Aesthetic management of connections
Between the two windows, we integrate a discreet vertical cable tray (capping) , in a color that matches the wall. It accommodates the insulated copper pipes , the communication cable and the condensate line. The route is very short (≈ 1 to 2 m) thanks to the back-to-back configuration, which limits pressure losses and promotes seasonal performance.
Condensate drainage
The elevated position provides reliable gravity drainage to the outside during the summer. The slope is controlled and protected against backdrafts; a non-return valve is provided to prevent any odors. In winter, defrosting of the outdoor condenser is taken into account to avoid creating ice accumulations near the access points.
Exterior side (site overview): a short, clean and sustainable route
Even if we focus here on the inner head, the success of the project rests on a coherent whole:
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Neat single drilling, waterproofing to the envelope with compatible flashing and mastic;
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Refrigerant connections brazed under nitrogen , then tested and drawn under deep vacuum to guarantee a clean circuit;
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Clearances maintained around the condenser to ensure good air circulation in all seasons.
Commissioning: precision and longevity
Our technicians carry out:
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Electrical check : dedicated circuit, sized circuit breaker, correct polarity and disconnector accessible from the outside.
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Refrigeration control : pressure/temperature, superheat and subcooling measurements to ensure circuit balance.
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User settings : explanation of modes (heating, air conditioning, dehumidification), automatic restart and adjustment of the fins to avoid direct blowing on the seating area.
Observed results
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Rapid increase in comfort and stable temperature thanks to modulation;
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Very low noise level in automatic speed - an advantage for open living spaces;
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Humidity better controlled in summer, especially during the hot and humid episodes frequent in Montreal .
Good practices for daily use
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Leave the heat pump in Auto mode or gentle modulation during mid-seasons: this is when efficiency is at its maximum.
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Adjust the direction of the flap to extend the jet under the ceiling; avoid blowing directly towards the seats or the table.
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Clean the filters every 4 to 8 weeks during periods of use; a clean filter reduces noise and consumption.
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In harsh winters, keep a moderate setting (e.g. 21°C) and let the device modulate rather than alternating frequently with a top-up.
HVAC Maintenance: Maintaining Performance
An annual HVAC maintenance by our teams includes:
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internal battery inspection, gentle dusting and fin check;
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checking the condensate drain and the sealing of the drilling;
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fan , probe and communications control;
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operating record (intensities, supply/return temperatures) and usage recommendations.
This maintenance maintains seasonal efficiency, extends component life and protects the warranty.
Pitfalls to avoid in Montreal housing
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Head too close to the ceiling : reduces suction and increases noise. We maintain adequate clearance.
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Undersized duct : crushing of insulation → losses and risk of condensation. We reserve a sufficient section and wide curves.
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Poorly located exterior outlet : air discharge facing an obstacle or immediate neighbor. We position the condenser with standard clearances .
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Lack of drain slope : overflows in the middle of summer. We check the slope and install an anti-siphon if necessary.
Sizing and load calculation
Before installation, we carry out a sizing based on the envelope (walls, windows, roof), the orientation and the actual occupancy of the room. The objective is to obtain:
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low-speed operation most of the time (better acoustics, better efficiency);
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efficient defrost cycles in winter;
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an airflow adapted to open volumes, very common in plex renovations.
Grants and support
Efficient wall-mounted heat pumps are generally eligible for programs based on performance and address. We verify your eligibility and work with you to prepare the process for Montreal , Laval , Longueuil , the North Shore , and the South Shore . Our team ensures that your equipment and its installation meet the technical requirements.
What you gain with AirGreen
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Personalized study and written recommendation;
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Clean HVAC installation (ducts, drilling, finishes);
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Instrumented commissioning and training in use;
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Local, responsive after-sales service and scheduled maintenance .
Summary sheet — MHM Project
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System : Tosot, wall-mounted heat pump (recent R-32 range)
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Configuration : back-to-back , vertical chute between windows
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Refrigeration path : short (≈ 1–2 m), continuous insulation
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Condensates : gravity drainage with controlled slope
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Electricity : dedicated circuit and external disconnect switch
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Main benefits : silence, even diffusion, high yield in mid-season
At AirGreen, we consider each HVAC installation at the level of the home and the neighborhood. Here in Mercier–Hochelaga-Maisonneuve , the Tosot wall-mounted unit above the windows provides discreet comfort, controlled energy consumption, and a finish that meets the expectations of Montreal homeowners.