A precise and careful night-time project: an HVAC installation designed for four-season comfort, efficiency and longevity in a residential building in Saint-Laurent .
Project context and client objectives
At AirGreen , we regularly work in plexes and condominiums in the Saint-Laurent district, where the challenge is to reconcile winter heating performance , silence in the evening and discreet integration on the brick facade. Here, our client wanted:
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stabilize the temperature of living rooms all year round;
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reduce energy costs compared to resistive heating;
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obtain reliable, easy-to-maintain equipment that is eligible for major grant programs when relevant.
We recommended a Gree wall-mounted heat pump (mini-split) , an ideal solution for apartments and condominiums in Greater Montreal thanks to its excellent performance/cost ratio and its suitability for extreme cold on recent ranges.
Facility architecture: clean, compact, sustainable
Our team chose a one-head, one-condenser configuration for targeted distribution in the main area. Highlights:
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Gree outdoor condenser mounted on galvanized wall brackets at a safe height to clear snow accumulated in winter and maintain air circulation on three sides.
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Refrigerant connection management with continuous insulation; compact service loop to facilitate control operations and avoid tension points.
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Condensate drainage by gravity slope towards the outside, avoiding an additional pump and reducing noise and maintenance.
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Short line routing (direct wall-to-wall drilling) to minimize pressure losses, optimize the COP in heating and reduce the visual footprint.
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Dedicated power supply , in accordance with the currents required by the capacity range of the chosen series, with suitable circuit breaker at the housing panel.
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Anti-vibration at the support points to contain micro-resonances from the brick facade and maintain a very low exterior noise level .
Result: a sober , perfectly stable pose, ready to face the freeze-thaw cycles typical of Montreal.
Why Gree for this type of building?
We frequently select Gree for Montreal condominiums and plexes. The reasons are clear:
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High seasonal efficiency (SEER/HSPF) on recent wall-mounted ranges, with extreme cold versions capable of heating efficiently at sustained negative temperatures.
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Flexible capacity ranges (in practice 9,000 to 24,000 BTU for a residential mono-split), which allows the power to be precisely adapted to the actual thermal load of the home.
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Controlled acoustics , an essential criterion in dense environments (balconies, interior courtyards, alleys).
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Reliability of electronic cards and availability of parts in Quebec, reducing delays in the event of corrective maintenance.
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New generation refrigerants available on several Gree series in R-32 , advantageous for environmental footprint and efficiency (useful information for future replacements or additions).
Responsible sizing: our method
We always size a heat pump based on a thermal load , not just a surface area. Our approach:
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Envelope analysis: brick walls, party walls, windows, air infiltration.
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Actual use of rooms: occupancy level, internal features (appliances, lighting).
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Orientation and sunshine: crucial for solar gains and summer/winter balance.
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Electrical verification: circuit length, gauge, and protection selectivity.
This rigor avoids the two classic pitfalls: oversizing (short cycles, discomfort, premature wear) or undersizing (lack of heat in the January peaks).
Technical details delivered on this site
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Wall support : galvanized steel, anchors adapted to the structural block behind the brick, level checked by laser.
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Clearances : respect the manufacturer's lateral and upper distances to preserve air exchange.
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Refrigeration lines : brazing, deep vacuum, leak testing and triple pointing (pressure, temperature, subcooling/superheating) upon commissioning.
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Drilling management : clean crossing with ring and sealing for air and water tightness.
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Winter protection : height compatible with snow accumulations and maintenance of the facade floor.
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Finishing : storage of technical surpluses in the condenser service area for a clean aesthetic.
Comfort and performance: what to expect
A wall-mounted heat pump from the Gree family delivers:
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Continuous heat in mid-season and winter, with inverter modulation to maintain the setpoint smoothly.
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Air conditioning in summer with controlled dehumidification , essential for perceived comfort.
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Very low interior noise thanks to the variable blower, which is appreciated in the evening.
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Substantial energy savings compared to pure electric heating, particularly visible on winter bills.
Grants and Eligibility
Depending on the installed range and nominal low-temperature performance, our wall-mounted installations may be eligible for certain energy efficiency support programs in Quebec. We systematically verify:
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Energy Star criteria (if applicable);
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performance requirements at -25°C / -30°C for Nordic heating;
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the conformity of the installation (dedicated circuit, documentation, photos).
We support our clients in Montreal, Laval, Longueuil, North Shore and South Shore in preparing the file and providing proof of compliance.
HVAC maintenance: maintaining performance over time
To maintain performance, we offer a tailored HVAC maintenance plan :
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cleaning the wall head filters (every 4–8 weeks depending on usage);
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annual inspection of heat exchanges , drains and line insulation;
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checking electrical connections and operating pressures;
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Checking clearances around the condenser before winter (snow, leaves, objects).
A well-maintained device retains its performance , its sound discretion and its durability .
Best practices in co-ownership and plexes
In dense areas like Saint-Laurent , we pay particular attention to:
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the location of the condenser to limit sound propagation to neighbors;
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working hours in consultation with the co-ownership union;
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management of condensation water to prevent drips on facades and paths;
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the aesthetics of the routes (coordinated cappings, short lines, discreet drilling).
Common Mistakes to Avoid (and How We Avoid Them)
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Underestimating the snow depth : a condenser that is too low will block. We install it high and clear.
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Ignore rear/side clearances : the machine "chokes". We respect the manufacturer's distances .
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Leaving poorly supported loops of lines : risks of vibration and wear. We secure each section.
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Drilling without sealing : water/air infiltration. We systematically seal .
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Size "by eye" : random comfort. We calculate the load and validate during commissioning.
What the customer gains here, concretely
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Year-round stable comfort in living spaces.
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An energy bill optimized by inverter modulation.
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A visually discreet and quiet system for the neighborhood.
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An installation ready for grant applications when the range meets the criteria.
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AirGreen support : assistance, maintenance, parts and advice for the entire life of the device.
Are you in Montreal, Laval, Longueuil, North Shore or South Shore?
We understand the constraints specific to each neighborhood: narrow streets, brick facades, typical exterior staircases, limited parking, flat roofs. Our method adapts to your building, without compromising on quality and safety . Whether you are in a condo in the Southwest , a semi-detached house in Brossard , a triplex in Villeray or a house in Sainte-Dorothée , we size, install and maintain your heat pump with the same high standards.
Express FAQ
Does this installation heat well in the middle of a Montreal winter?
Yes, Gree wall-mounted ranges suitable for cold climates maintain a useful capacity below -20°C. We validate the performance curve when choosing the model.
Which capacity to choose (9k, 12k, 18k, 24k)?
It all depends on the thermal load and room configuration. We provide you with a clear sizing plan before ordering the equipment.
What if I want to add a second head later?
This is possible via a dedicated MultiZone configuration. We guide you through the advantages/disadvantages of two separate mono-splits .
Is the interview complicated?
No. Simple actions (filters, clearances) and an annual inspection are enough to maintain high performance and extend the lifespan.
Conclusion
This Gree installation in Saint-Laurent illustrates our way of working: clean execution , consistent technical choices, attention to details that make the difference in winter as in summer. Are you looking for a similar project in Montreal , Laval , Longueuil , on the North Shore or the South Shore ? Let's talk about your building, your objectives and the best HVAC strategy for your comfort.