A wall-mounted solution that defies Québec winters—even at -30°C
When winter temperatures drop far below zero, many homeowners wonder if a wall-mounted heat pump can truly act as the main heating system in their home or if it's only suited for a secondary, backup role. At AirGreen, we’ve installed hundreds of wall-mounted heat pumps across Montréal, Laval, Longueuil, the North Shore, and the South Shore, and our answer is clear: yes, a properly selected, professionally installed, and well-maintained wall-mounted heat pump can efficiently heat a home even during extreme cold spells of -30°C.
This isn’t just theory. It’s based on real-life installations we’ve completed for clients in single-family homes, duplexes, and condos—some exposed to harsh winds or near the water. Here’s a comprehensive look at what enables a wall-mounted heat pump to serve as a full-time heating solution, even in Québec’s harshest weather.
The myth of limited heating: an outdated perception
For years, people believed wall-mounted heat pumps lost all effectiveness below -15°C. That myth, though persistent, has been entirely debunked by the remarkable evolution of HVAC technology.
New generation units—such as the Gree Sapphire, Fujitsu KZAH, or Mitsubishi Zuba—are specifically engineered for northern climates and maintain stable performance down to -30°C, and even -35°C for some models. These systems come equipped with inverter compressors, smart defrost cycles, ultra-precise modulation, and consistently quiet operation.
Case study: Sainte-Marthe-sur-le-Lac, -32°C in January
This past January, a client in Sainte-Marthe-sur-le-Lac, on the North Shore, contacted us to replace their aging oil system that had become costly and unreliable. We installed an 18,000 BTU Gree Sapphire wall-mounted heat pump.
This unit is certified to deliver 100% of its heating capacity at -30°C, with a SCOP rating of 4.8 and outstanding energy efficiency. Thanks to its variable-speed compressor, it provided consistent heat all winter long without needing any backup system—even during a cold snap that hit -32°C overnight.
Choosing the right unit: the importance of proper sizing
It’s not enough to choose a model known for cold weather performance. True expertise lies in the precise sizing of the system according to your home's specific characteristics: surface area, insulation quality, sun exposure, ceiling height, and overall airtightness.
At AirGreen, we always perform a thorough thermal evaluation before installation. We’ve often replaced undersized units installed by other contractors that only heated part of a house, leaving cold zones or overworking the unit at full capacity—shortening its lifespan and underperforming when needed most.
Professional installation: a critical performance factor
Even the best wall-mounted heat pump won’t reach its full potential if poorly installed. At AirGreen, our certified technicians ensure:
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Installation complies with CSA and RBQ standards
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Optimal placement of the indoor unit for even heat distribution
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Smart routing of refrigerant lines, even in complex layouts
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Effective drainage management to prevent freezing or overflow
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Complete airtightness check, vacuuming, and real-time performance testing at startup
Every installation is documented, with full technical reports and personalized maintenance recommendations.
Primary system or hybrid: what’s the best strategy?
Most of our clients in Montréal, Laval, and other regions today choose a wall-mounted heat pump as their main heating system, with occasional support from a secondary system (like baseboard heaters or a gas fireplace).
This hybrid model, when properly configured, allows you to maximize energy savings and reduce greenhouse gas emissions while ensuring uninterrupted comfort during the coldest days.
In practice, a properly selected heat pump covers on average 95% of annual heating needs in a well-insulated home. A backup source is only useful during extreme days—typically no more than 5 to 10 days per year.
Government grants for high-performance heat pumps
Thanks to programs like Hydro-Québec’s LogisVert, Chauffez Vert, and Rénoclimat, many wall-mounted heat pump models installed by AirGreen qualify for financial assistance of up to $2,500.
For example, during an installation in Brossard, we helped a client receive a $1,860 rebate for her 24,000 BTU Gree Extreme, which she now uses as her main heating system. Our team also handles all the paperwork involved in securing these grants.
Maintenance: the key to long-term performance at -30°C
Even a high-performance system needs regular HVAC maintenance to maintain its efficiency over the years:
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Filter and coil cleaning
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Refrigerant level checks
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Inspection of electronics and fans
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Heating mode performance tests during extreme cold
Our team provides annual preventative service, complete with comprehensive diagnostics and tailored recommendations. This helps not only prevent breakdowns, but also maintain peak performance—even on frigid days.
Conclusion: a clear answer, backed by experience
Yes, a wall-mounted heat pump can heat your home even at -30°C, provided that:
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You choose a model designed for Québec’s climate
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The system is properly sized for your home
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Installation is performed by a qualified contractor like AirGreen
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You follow a routine maintenance schedule
We have dozens of satisfied customers who heat their homes exclusively with a wall-mounted heat pump, from Vieux-Longueuil to Boisbriand, and even Ville Saint-Laurent—without ever turning to another heating source.
For questions or to plan your HVAC installation, contact us today. At AirGreen, we bring our hands-on experience and commitment to excellence to ensure your winter comfort.