Four-season comfort in a Montreal plex without compromising aesthetics
In a typical Plateau-Mont-Royal plex apartment, we installed a Sharp ZU1 series wall-mounted heat pump (R-32 refrigerant) to provide stable comfort year-round, with a minimal visual footprint. The sleek indoor unit sits above a storage alcove : a configuration that optimizes air diffusion in the living area while freeing up floor space—a priority in Montreal's space-efficient homes.
Customer needs: reliable heating, gentle air conditioning, controlled energy bill
The owner was looking for an HVAC solution capable of:
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Heating efficiently during the cold January weather,
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Refresh without harsh drafts during heat waves,
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Reduce electricity consumption compared to portable appliances or an old windowed air conditioner,
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Respect the interior character (moldings, woodwork, folding storage doors).
The Sharp ZU1 series meets these expectations thanks to a responsive inverter compressor , a low-temperature operating range suitable for the metropolitan climate and a very low noise level .
Reading the place and issues specific to the Plateau
The row houses of the Plateau-Mont-Royal often impose restricted technical routes : party walls, narrow alleys, high ceilings with moldings, and sometimes limited exterior access. Our approach consists of:
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Limit visible drilling ,
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Choose a discrete connection path (refrigerants and condensate),
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Preserve existing moldings and finish ,
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Reduce piping length to maintain optimal performance.
Interior integration: clean, tall and perfectly aligned
Positioning. The unit is fixed at the top , centered above the closet opening. This height allows:
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Reduced air stratification ,
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Wide diffusion in the living room and hallway,
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A free air return to the suction.
Route of the connections. The insulated copper lines and the power cable leave the unit on the left side , then run through the wall of the closet :
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Discreet light-colored cover to match the wall;
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Anti-vibration mountings at direction change points;
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Conformal bend radii to preserve refrigerant charge.
Condensate management. The installation favors gravity drainage , without a pump, to the left where the natural slope is available. Advantages: silence , reliability and simplified HVAC maintenance .
Control and comfort. Motorized shutters direct the airflow under the ceiling to avoid direct spray onto the seating area. We program a gentle Auto mode by default for mid-season, and dehumidification settings for humid periods.
Exterior and Compliance (Technical Summary)
Even if the view presented is of the interior head, each AirGreen project respects a base of good practices :
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Nitrogen leak tests and deep vacuum until stabilization,
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Vapor barrier and continuous insulation on exposed sections,
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Mechanical protections at crossings (bulkheads),
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Selectors and circuit breakers sized according to the nameplate,
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R-32 charging documentation and commissioning with readings.
Why the Sharp – ZU1 series is a good fit for the Plateau-Mont-Royal
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High seasonal efficiency (competitive SEER and HSPF) to lower operating costs .
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Quiet operation suitable for open living areas.
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R-32 : Refrigerant with reduced global warming potential compared to older R-410A systems.
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Inverter algorithms : fine power adaptation, fewer on/off cycles, reduced wear.
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Compatibility with assistance programs generally offered when performance criteria are met (depending on configuration and power).
Stages of an AirGreen construction site on a plex
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Technical visit : taking measurements, identifying possible gravity drops, routing lines to the backyard or alley.
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BTU sizing : quick load calculation (envelope, exposures, volumes), validation of a 12,000 BTU size for the main area.
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Integration plan : preservation of moldings and folding doors, single optimized opening behind the drop.
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Preparation : surface protection, fixing templates, dowels suitable for existing masonry and wood.
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Installation and brazing : silver brazed connections, nitrogen flushing during welding.
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Vacuum / charging : vacuum ≤ 500 microns , stabilization, charge compensation if necessary.
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Commissioning : electrical checks, supply/return temperatures, explanations to the customer (modes, filters, maintenance).
Results observed
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Rapid temperature rise in extreme cold thanks to low temperature efficiency.
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Even cooling in summer, without the feeling of a draft on the sofa opposite.
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Very low noise level : undisturbed teleworking/videoconferencing exchanges.
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Controlled visual impact : positioning above the storage frees up walls and preserves character .
HVAC Use and Maintenance Tips
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Heat mode in winter with stable setpoint (20–21°C) to let the inverter work at low speed.
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Horizontal heating fins to push air under the ceiling and let it fall naturally.
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Clean filters every 6–8 weeks; annual service call for electronic and refrigeration check .
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Clearances around the unit and condensate drainage checked at the start of each season.
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Remote control : Activate the I-Feel/Follow Me function when temperature measurement at the point of life is desired.
Pitfalls to avoid in similar accommodations
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Multiple openings that weaken a thin partition: we favor a single multi-service passage .
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Condensate pump not required : noise and maintenance; gravity should still be preferred when there is a slope.
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Length overloads (beyond the manufacturer's thresholds): these degrade performance ; hence the benefit of a short route via the closet.
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Undersizing on open areas: a 9k may seem attractive, but 12k proves to be more stable here and avoids maximum stress in heat waves.
Why choose AirGreen for your HVAC installation in Montreal, Laval, Longueuil, North Shore and South Shore?
We size, install, and optimize wall-mounted heat pumps and air conditioners , paying particular attention to local architecture: plexes, condos, suburban homes. Our strength:
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Technical rigor (tests, protocols, documentation),
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Careful finishing (aligned capping, clean drilling, discreet wiring),
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Support for subsidies when the equipment and the file are eligible,
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Responsive after-sales service to guarantee durability and peace of mind .
Installation Quick Facts
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Type : wall-mounted heat pump ( mini-split )
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Brand : Sharp
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Range : ZU1 series (R-32)
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Capacity : 12,000 BTU (main living area)
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Route : exit on the left, discreet path in the alcove , clear hood
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Condensate : gravity
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Objective : four-season comfort with optimized consumption and aesthetic integration into the Plateau style
Final word
This installation of a Sharp – ZU1 series in Plateau-Mont-Royal illustrates our way of working: analyzing the space , choosing the right equipment , installing it properly , finely calibrating and transmitting good usage practices . The result: lasting comfort , respectful integration into the decor and controlled cost – the AirGreen signature in Greater Montreal.