How Québec’s harsh winters directly affect the performance and longevity of your wall-mounted heat pump
At AirGreen, we understand that Québec’s unique climate conditions pose very specific challenges to HVAC systems, especially wall-mounted heat pumps. Our long, humid, and harsh winters—combined with drastic temperature swings—can speed up component wear, compromise advertised energy performance, and significantly reduce the life expectancy of your unit. This article outlines in detail the little-known effects of extreme temperatures, backed by real cases from our team in the field across Montréal, Laval, Longueuil, the North Shore, and the South Shore.
Extreme temperatures = increased mechanical stress on the heat pump
When temperatures drop below -15 °C, a wall-mounted heat pump has to work harder to extract heat from the outside air. This puts extra stress on:
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The compressor, operating at high pressure
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The fans, running for extended periods
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The automatic defrost system, activating repeatedly
Real-world example:
In Boisbriand, we replaced a Sharp ZU1 18,000 BTU heat pump that showed signs of premature wear after just five years. The culprit? Constant exposure to temperatures below -20 °C and a lack of routine maintenance.
Frequent defrost cycles speed up component fatigue
In winter, moisture in the air quickly freezes on the outdoor unit. To counter this, the heat pump automatically enters defrost mode, reversing the refrigerant cycle to melt the ice. But if these cycles happen too often:
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The compressor undergoes unnecessary strain.
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Electronic components are exposed to sudden thermal variations.
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The system consumes more energy, lowering overall efficiency.
Salt, moisture, and ice: the silent enemies of outdoor installations
In several boroughs of Montréal and Longueuil, the humid winter air combined with road salt creates an especially corrosive environment. This leads to:
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Oxidation of the outdoor coil fins.
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Corrosion of screws, lines, and mounting brackets.
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Premature damage to the heat exchanger.
What we do at AirGreen:
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Apply anti-corrosion coatings to exposed components.
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Raise the outdoor unit to prevent snow and salty water buildup.
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Choose brands with enhanced protections, like Gree Extreme, Fujitsu KZAH, or Midea Arctic.
Case study: job in Saint-Bruno with a Gree Extreme 24,000 BTU
A duplex owner in Saint-Bruno-de-Montarville reached out after two winters of heavy use of a Gree Extreme heat pump. Despite the model’s strong reputation, the unit showed decreased performance and inconsistent heating cycles.
Analysis:
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The unit was installed too close to the ground, exposed to road salt splashes.
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The outdoor fan was clogged with icy dust.
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No preventive maintenance had been done.
AirGreen solution:
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Full cleaning and deoxidation of the coil fins.
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Adjustment of the defrost cycle to match the local humidity.
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Raising the unit on a galvanized steel platform.
How to extend the lifespan of your wall-mounted heat pump despite Québec’s climate
Choose the right location from the start
At AirGreen, we prioritize placements that are:
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Sheltered from direct wind
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Away from water runoff zones
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Naturally ventilated
Perform a complete HVAC maintenance at least once a year
Which includes:
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Cleaning of coils
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Inspection of electrical components
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Checkup of the defrost system
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Lubrication of the fan motor if needed
Use models built for Québec winters
Some brands are specifically designed to deliver stable performance down to -25 °C or even -30 °C:
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Fujitsu KZAH: outstanding performance in extreme cold
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Sharp ZU1: robust inverter technology
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Gree Extreme: built for Canadian winters
Client testimonial in Laval: strong performance after 8 winters
“We were worried a wall-mounted heat pump wouldn’t last long in Laval’s winters. But with the Fujitsu KZAH 12,000 BTU installed by AirGreen and annual maintenance, the system is still running like new after 8 years.”
— Lemoine Family, Laval
Best practices to protect your wall-mounted heat pump
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Never cover the outdoor unit with a tarp: this traps moisture
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Clear snow from around the unit after each storm
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Raise the unit to avoid pipe freeze-ups
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Schedule preventive maintenance every fall
Conclusion
Québec’s extreme climate conditions are tough on wall-mounted heat pumps. But with a proper installation, a well-suited unit, and rigorous maintenance, your system can easily last 10 to 15 years or more. At AirGreen, our expertise across Montréal, Laval, Longueuil, the North Shore, and the South Shore allows us to help clients maximize comfort and protect their investment for the long haul.