Four-season comfort for a brick plex, without compromising on aesthetics or efficiency
At AirGreen , we are regularly called upon to modernize the comfort of homes in Southwest Montreal , where brick Plexes and lush backyards rub shoulders. Here, our team is installing a Sharp ZU1 series wall-mounted heat pump ( R-32 refrigerant), chosen for its performance in cold weather, low consumption and quiet sound, all perfectly suited to the neighborhood life of Saint-Henri .
The context of intervention
The apartment features a large window overlooking the courtyard, with an interior lintel ideal for accommodating the wall header . The choice of this positioning is not only aesthetic: placed high and in the center of the volume, it promotes the even diffusion of air in the main room and limits areas of thermal shadow, a recurring issue in the narrow and deep housing of Montreal plexes.
What we have achieved, point by point
Sizing and Selection
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Device type: wall-mounted heat pump ( mini-split ).
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Brand: Sharp .
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Range: ZU1 (R-32, low temperature).
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Typical capacity range: 12,000 to 18,000 BTU depending on thermal load; here, the load calculation and occupancy profile have guided towards a capacity in the 12 k family to optimize cycles and efficiency.
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Customer objectives: silent air conditioning in summer, economical additional heating in winter, visual sobriety, simplified future access for HVAC maintenance .
Refrigeration and electricity route
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Single drilling at the back of the head, inclined for gravity drain (no condensate pump → increased reliability, zero additional noise).
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Short refrigerant connections (≈ 2.5 to 3.5 m) between the indoor unit and the outdoor condenser installed on the courtyard side: minimized pressure losses, maximized COP .
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Dedicated power supply with compliant circuit breaker, protected wiring and capped routing for a clean and durable finish.
Outdoor installation
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Condenser fixed on galvanized wall brackets above the snow and debris area, clearances respected for air flow, orientation avoiding direct blowing towards the neighborhood.
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Winter management: natural de-icing ensured by height and flow; sufficient space for maintenance and portable snowplow.
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Anti-vibration pads to reduce the transmission of structural noise into the brick.
Methodical commissioning
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Deep vacuum (< 500 microns), nitrogen test and ambient humidity reading to validate the drain.
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Checking for overheating/subcooling based on daytime conditions, reading intensities and setting head sweep angles to avoid drafts in the window seating area.
Result: comfort, silence and savings
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Reliable heating down to the low temperatures advertised by the ZU1 series, ideal for reducing the load on the main system in mid-season and winter peak.
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Fast air conditioning thanks to the wide shutter and upper positioning, without direct blowing on the occupants.
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Energy efficiency: R-32 and the inverter limit consumption, particularly in maintenance mode.
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Aesthetics : discreet integration into the lintel, light-colored cladding along the wall, no visible cable drop.
What we're monitoring in Southwest plexes
1) Height and recirculation near large windows
Large facade or courtyard windows can create plumes of cold air in winter. We adjust the vertical sweep to circulate the volume without "hitting" the cold zone, for superior subjective comfort at the same temperature.
2) Gravity drain and backflow protection
A service siphon and a continuous slope prevent odors from rising and overflows during summer humidity episodes. If this is not possible, we offer a silent condensate pump , but here gravity was made possible and preferred.
3) Neighborhood and structural noise
The metal staircases and balconies of the Southwest carry sound. Hence the use of anti-vibration pads and careful decoupling of the brackets on the brick, significantly reducing transmission.
Local Grants and Eligibility
High-performance R-32 wall-mounted heat pumps like the Sharp ZU1 are generally eligible for Quebec's current assistance programs (based on performance and configuration criteria). We support each client: preparing the application, providing proof of installation, and calculating savings. Our team monitors the conditions of the main programs active in Montreal, Laval, Longueuil, the North Shore, and the South Shore to maximize your return.
Good HVAC Operation and Maintenance Practices
Settings to favor
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Auto/Heat mode at low speed in the off-season to smooth out cycles.
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Slightly stable setpoint (21–23°C) rather than large variations: better seasonal performance .
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Fins oriented to wash the side walls and not the sofa.
Preventive maintenance
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Filters : cleaning every 4 to 8 weeks in summer; dusting less frequently in winter depending on use.
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Exchanger : annual inspection, pressurization and gentle cleaning as needed.
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Drain : purge with clear water in spring.
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Condenser : minimum clearance of 30 cm, gentle rinsing of the fins, checking of the support before winter.
Regular HVAC maintenance extends lifespan, maintains advertised performance, and prevents odors or whistling noises related to turbine dirt.
Why this Sharp – ZU1 series, here?
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Urban compatibility : discreet size, interior/exterior silence .
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R-32 : better environmental profile than older generations.
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Low temperature range : useful additional heating without using energy-consuming convectors.
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Intuitive controls : modes, timers, dehumidification, perfect for apartment living with variable schedules.
AirGreen expertise serving Montreal buildings
We work daily in dense neighborhoods such as Le Sud-Ouest , Rosemont–La Petite-Patrie , Villeray , Ville-Marie , and Verdun . Our teams are familiar with the structural features (brick walls, steel lintels, rear staircases, narrow courtyards) and neighborhood requirements . Each HVAC installation is planned: appointments are made, traffic protection is ensured, measurements are taken, tests are carried out, and a personalized user guide is provided.
Do you want the same level of quality for your home in Montreal, Laval, Longueuil, North Shore or South Shore ? We offer 100% free on-site visits, transparent pricing , and invoicing at the end – when you are 100% satisfied .