Four-season comfort in a Montreal plex without compromising on aesthetics or energy efficiency
Project context and comfort objectives
At AirGreen , we work daily in apartments and plexes in the Plateau-Mont-Royal region where space is limited and architecture deserves to be respected. Our client wanted discreet cooling for the summer and efficient heating support during the off-season, without invasive work or visible ducts. We recommended the installation of a recent Sharp wall-mounted heat pump with R-32 refrigerant , a solution that combines simplicity, high efficiency and proven reliability for Greater Montreal .
In this typical Plateau dwelling (painted interior walls, slatted ceiling and period moldings), the main challenge is to integrate the interior head high up, close to the ceiling, while optimizing air flow and condensate management, and limiting as much as possible the visual footprint of the passages to the outside.
Why a Sharp R-32 wall-mounted heat pump?
Performance and climate compatibility
The latest generation Sharp R-32 offers an excellent SEER/HSPF ratio and low temperature operating stability, suitable for urban conditions in Montreal and surrounding areas ( Laval , Longueuil , North Shore , South Shore ) when used for summer cooling and as supplemental heating in spring and fall. R-32, more efficient than R-410A, reduces the refrigerant charge for equal performance and improves heat transferability, resulting in controlled consumption.
Discretion and acoustics
Sharp wall units feature a sleek housing, multi-axis adjustable fins , and ultra-quiet night mode operation. Installed high up, the head aligns neatly under the molding; the smooth front blends naturally with the room's warm colors, without overpowering the view.
Simplified maintenance
The washable filters can be removed in seconds, and the hinged front cover provides clear access to the condensate drain. For our customers, this means fast preventative HVAC maintenance and long-term performance.
Sizing and capacity selection
In the Plateau-Mont-Royal , living room areas often vary between 20 and 35 m², with ceiling heights close to 2.6–2.8 m. Depending on the insulation, windows and orientation, we generally recommend a capacity of 12,000 to 18,000 BTU/h for a main area; the objective is to cover the sensible air conditioning load and provide a comfortable heating supplement, without oversizing.
Our approach is based on:
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a simplified room-by-room thermal load calculation,
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taking into account solar gains (south/west facing windows),
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the continuity of spaces (double living room typical of plexes),
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and actual usage (regular teleworking vs. evening occupation).
Path of connections and aesthetic integration
Inner head positioning
The Sharp head is installed high on the wall , under the cornice, to promote laminar airflow along the ceiling and controlled stratification . This placement maximizes room coverage and prevents direct drafts into living areas.
Wall crossing and condensate slope
Behind the unit, we made a 65 mm rear outlet hole , with a slight gravity slope (2–3%) towards the outside to drain the condensate naturally. This method avoids the need for a pump, reduces noise risk and simplifies maintenance. The sheath is insulated and sealed inside and out to ensure airtightness and prevent any moisture migration.
Refrigeration lines and external capping
Outside, the insulated copper refrigeration lines run through a protective cover (capping) matching the facade, ensuring a clean and durable finish. In the architecture of the Plateau backyards, we favor short routes, a gentle bend and a vertical descent towards the condenser installed on wall brackets or on an anti-vibration slab , depending on the condition of the facing and snow removal constraints.
Installation quality: what we systematically implement
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Plates and dowels adapted to the support (brick behind partition, half-timbering, etc.).
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Laser leveling of the head for correct condensate drainage and uniform blowing flap.
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Calibrated flares , tightening torques controlled by dynamometer on flare fittings.
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Deep vacuum (< 300 microns) followed by a nitrogen leak test to make the circuit reliable.
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Noise management : anti-vibration pads under the condenser, spacers and suitable fan speed selection.
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Finish : corking, UV neutral silicone seals, clean capping, discreet trunking in a matching color.
Ease of use and recommended settings
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Seasonal auto mode : convenient for switching from air conditioning to auxiliary heating as needed.
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Orientation of the fins : a wide horizontal sweep to mix the air mass under the ceiling and a slight vertical angle to avoid direct blowing onto the occupants.
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Fan speed : low/medium to limit noise levels in the evening; one-time turbo to quickly lower the temperature after a solar peak.
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Programming : time slots suitable for teleworking and nights; possible integration with a Wi-Fi gateway for remote control.
Grants and energy compliance
Recent R-32 wall-mounted heat pumps , when they reach recognized performance thresholds (e.g., Energy Star , cold climate), are eligible for provincial and municipal assistance programs depending on the period. We verify the alignment of performance and the required documentation for each mandate in order to optimize the overall acquisition cost / operating savings for our clients in Montreal, Laval, Longueuil, North Shore and South Shore .
HVAC Maintenance: The Winning Routine to Maintain Performance
Well-installed equipment deserves regular HVAC maintenance :
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Bi-monthly cleaning of washable filters.
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Annual inspection of the condensate drain (rinsing, slope control).
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Checking the fins of the outdoor condenser (gentle straightening if necessary, dusting).
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Electrical control and operating measurements (overcurrents, undervoltages, temperature differences).
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Light disinfection of the evaporator to prevent odors and maintain healthy air.
This routine extends the life of the appliance, maintains energy savings and safeguards indoor air quality .
Specific challenges solved on this site
1) Respect for heritage finishes
The slatted ceiling and molding require precise template taking . We moved the head a few millimeters apart to maintain free expansion without contact and to avoid any vibration transmission. The result is perfectly square, without irregular shadows.
2) Managing backyard constraints
The Plateau courtyard requires a compact exterior path to avoid obstructing the stairs and access to the recycling bins. The condenser's location was designed for free airflow , adequate snow clearance in winter and a distance that minimizes heat exchange with the walls exposed to the sun.
Result: immediate comfort and controlled bill
From the moment you start up, you can feel the uniform airflow and thermal stability . The gentle ventilation limits gradients, and the temperature rise in autumn is rapid thanks to the high mid-season coefficient of performance . In summer, the integrated dehumidifier improves the feeling of freshness without excessively lowering the setpoint, which reduces electricity consumption .
Best practices for housing in Plateau-Mont-Royal
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Avoid oversizing : An overly powerful unit results in short cycles, unnecessary noise and uneven comfort.
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Prioritize gravity for condensate drainage; use a pump only if the architecture requires it.
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Take care with the orientation of the blowing to cover both the living room and the dining room of the adjoining room plexes .
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Protect the condenser from falling ice and snow with a suitable canopy without obstructing the suction.
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Plan maintenance before the heatwave and before the first cold spells to take advantage of peak periods with optimal performance.
Why entrust your project to AirGreen?
Our team understands the constraints of Montreal buildings : brick walls, old partitions, cornices, alley access. We deliver clean, documented HVAC installations that comply with best practices: R-32 charging, vacuum draw, leak testing, careful finishing, operating instructions, and maintenance monitoring . Whether you are in Plateau-Mont-Royal , Laval , Longueuil , on the North Shore or the South Shore , we size, install and maintain your Sharp wall-mounted heat pump with the same high standards.
Quick FAQ: Questions our customers often ask
Can I heat my entire home with a single wall-mounted unit?
For a multi-partitioned plex, a single head is especially suitable for the living areas . For uniform comfort, a second head or a multi-zone is sometimes considered if the configuration lends itself to it.
What noise in night mode?
Sharp R-32 heads drop below the perceived threshold in a quiet room when the fan speed is in low mode; regular filter maintenance is essential to maintain this level.
What savings can be expected?
In air conditioning, a high SEER translates to a kWh saving for equivalent comfort. In supplemental heating, the mid-season COP reduces the use of electric baseboard heaters.
Are you considering a wall-mounted heat pump for a plex, condo, or townhouse in Montreal ? We assess your situation on-site, recommend the right brand and capacity , and deliver a discreet, efficient, and durable installation.
Strategic keywords : heat pump , wall-mounted air conditioner , HVAC installation , HVAC maintenance , Montreal , Plateau-Mont-Royal , Laval , Longueuil , North Shore , South Shore , Sharp , R-32 .