A targeted comfort upgrade for a Montreal home seeking efficiency and discretion
At AirGreen , we were contacted by a homeowner in Rosemont–La Petite-Patrie who wanted to stabilize the temperature of a very sunny room overlooking the backyard. The space presented a classic Montreal building constraint: a narrow exterior wall near a window and a curtain rod , with a low ceiling and little clearance for optimal air distribution. We offered a ComfortStar wall-mounted heat pump (compact indoor unit) to provide year-round heating and cooling , with a clean and controlled HVAC installation , without invasive work.
Why a wall-mounted heat pump here?
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4-season versatility : heating in the off-season and backup in the middle of winter depending on the compressor capacity; efficient wall-mounted air conditioner in summer.
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Higher efficiency than electric convectors for the same room.
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Quick installation on exterior wall, with gravity drain possible in most cases.
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Simplified HVAC maintenance : accessible filters and seasonal cleaning.
Location choice: corner near the window
We position the wall head just below the ceiling on the exterior wall, in the immediate vicinity of the window . This location offers several advantages:
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Short route to the outside (lateral drilling): refrigeration lines and communication cable of approximately 2 to 3 m to the condenser.
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Gravity drainage : the natural slope avoids the need for a condensate pump – less noise, less maintenance.
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Reduced downtime : single drilling, rapid finishing with exterior capping matching the facade.
However, we are paying attention to two sensitive points observed in this configuration:
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proximity to the ceiling and corner can trap airflow if the blade is not properly adjusted;
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the rod and curtains must not block the suction.
Our technicians adjust the blower blade towards the center of the room and maintain the recommended clearances around the hood.
Technical steps of installation
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Protecting the work area : tarpaulins and tape to avoid marking freshly painted walls.
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Installation of the interior support : laser check of the level, anchors adapted to the type of wall (wood/brick).
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Through hole approximately 65 mm , inclined outwards for the gravity drain .
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Connections : insulated copper, 14/4 or 16/4 cable depending on the series, and reinforced PVC drain pipe.
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Exterior finish : UV-resistant waterproof capping , water drop elbow and neutral silicone to prevent infiltration.
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Refrigeration connections : torque flaring, deep vacuum < 500 microns , nitrogen leak test.
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Powering up and starting up : checking polarity, calibrating the fan, checking the exchange surfaces and the blowing temperature .
Expected result: a drop of 8 to 12°C when blowing in air conditioning mode (depending on conditions), and an air flow that sweeps the room without creating a direct draft on the occupant.
Observed particularities and solutions
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Tight wall corner : we refocus the air jet by fine-tuning the flaps to avoid immediate recirculation against the ceiling.
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Presence of the rod : we validate that the curtain does not cover the high suction of the unit; if necessary, we offer a spacer to clear the head 10 to 15 mm from the wall.
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Interior aesthetics : discreet finishing of the drilling behind the hood, local paint touch-up included when stipulated in the quote.
About ComfortStar Equipment
The selected ComfortStar wall head is a compact and quiet unit, suitable for rooms from 12,000 to 18,000 BTU depending on the load calculation (orientation, glazing, floor, infiltration). The control panel indicates the cooling/heating modes , the ventilation speed and the temperature . Without displaying a precise reference, this range is distinguished by:
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a dehumidification mode useful during Montreal's humid heat waves;
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a resumption of instructions after a power cut;
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easily accessible washable filters .
When required, we confirm eligibility for grants (provincial/municipal programs) based on low temperature performance and approvals of the specific series installed. We manage this verification for you, whether you are in Montreal , Laval , Longueuil , on the North Shore or the South Shore .
Sizing: Avoiding Costly Mistakes
We systematically perform a room-by-room load calculation . Oversizing a wall-mounted heat pump leads to short cycles , unnecessary noise , and less effective dehumidification . Conversely, a unit that is too small will run continuously without reaching the setpoint. Our methodology takes into account:
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of the exposure (west/south),
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the type of glazing and infiltrations ,
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the ceiling height and the surface area actually treated,
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internal gains (equipment, occupants).
Air distribution: settings for this type of room
In a window-near configuration, we aim for a range that crosses the room:
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Horizontal flap slightly downwards so that the jet travels 3 to 5 m before rising again.
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Vertical sweep activated in summer comfort, deactivated in heating to avoid destratifying the hot air too quickly at the start of the cycle.
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Automatic speed preferred, with manual shift to low at night.
Condensate management
Here, the gravity drain is retained: continuous slope, collars every 60 cm , external outlet with water drop to prevent the coating from blackening. If this is not possible (ascending length, complex crossing), we install a silent condensate pump with anti-vibration tray and safety cut-out .
Exterior finishes and climate resistance
The short route allows discreet cladding of the lines towards the condenser:
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UV and frost resistant capping ,
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stainless steel screws,
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clear height to stay above the snow line and facilitate winter HVAC maintenance .
When the condenser is in operation, we recommend wall brackets or a stable platform (slab on a draining base), which are more effective than simply supporting it on the ground.
Maintenance recommended by AirGreen
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Filter cleaning : every 4 to 6 weeks during periods of intensive use.
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Washing the batteries and the tray : annual, to prevent odors and loss of performance.
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Drain inspection : when the snow melts and at the beginning of summer.
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Refrigeration check : every 2 years (or depending on usage) to confirm operating pressures and temperatures.
What we deliver to the customer
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A clean, aligned and tested installation ,
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a configured and explained remote control ,
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usage advice (realistic instructions: 23–24°C in summer, 21–22°C for heating a living room),
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a file : detailed invoice, installation photos, and – if eligible – support for subsidies for the Montreal , Laval , Longueuil , North Shore and South Shore sectors.
Pitfalls to avoid (feedback)
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Stick the head to the ceiling : there must be sufficient clearance for the hot/cold air to recirculate correctly.
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Ignore curtains/rods : they can obstruct the suction.
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Horizontal drilling without slope : risk of water backflow during thaw.
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Poorly closed capping : water infiltration and frost in winter.
Our teams check each of these points on site.
Comfort assessment
After commissioning, the room immediately gains thermal stability : fewer temperature differences between the window corner and the center, better controlled humidity in summer, and minimal noise pollution thanks to the low-speed internal fan. The customer has a system that is economical to use and ready for the seasons to come.
Frequently Asked Questions (Greater Montreal)
Is this compatible with a future multi-zone addition?
In many cases, yes, if the external series allows it. We check backward compatibility .
What if the electrical panel is far away?
We plan a dedicated circuit and optimize the route to limit the visual footprint while respecting the code.
What about harsh winters?
Depending on the series and its cold performance, the heat pump can heat a substantial portion of the season. We always recommend a hybrid strategy and appropriate settings during very cold weather.
AirGreen, your local HVAC partner
Established and active in Montreal , Laval , Longueuil , on the North Shore and South Shore , we master the specificities of plexes, condos and suburban homes. We combine thermal diagnostics , careful HVAC installation and rigorous HVAC maintenance to guarantee lasting comfort and measurable savings.