Unmatched performance in a demanding urban setting
In Montréal, harsh winters, humid summers, and unpredictable temperature swings constantly put HVAC systems to the test. In this context, the exceptional longevity of a Lennox wall-mounted heat pump installed by our team at AirGreen recently caught our attention — and that of several professionals in the field. This article takes a detailed look at this unique case study, revealing the secrets behind this remarkable installation that, more than a decade later, is still operating with impressive efficiency.
Installation background: a key project revisited in Montréal
This project took place in the Villeray neighbourhood of Montréal, inside a residential duplex built in the 1950s. In fall 2012, we installed a Lennox MLA18 wall-mounted heat pump (18,000 BTU/h). The homeowner, focused on reducing energy consumption while improving indoor comfort, was looking for a solution that was energy-efficient, minimally invasive, and reliable over time.
Why this Lennox model?
The Lennox MLA18 is part of Lennox’s Elite series, known for its stable performance and consistent energy efficiency. Key technical features include:
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Capacity: 18,000 BTU/h
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Type: Wall-mounted heat pump (mini split without ductwork)
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Energy Efficiency: SEER 23 / HSPF 10.5
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Inverter Technology: automatic compressor speed adjustment
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Quiet Operation: 24 dB(A)
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Cold Weather Performance: down to -30°C
This model became the obvious choice after a full evaluation of the building, insulation quality, and energy use patterns. We recommended Lennox for its reliability in Québec’s winters, and for its dependable performance in both heating and cooling modes.
A well-executed job with a tailored configuration
The project involved several technical challenges:
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The exterior walls were made of solid brick, complicating the installation of the wall brackets.
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The electrical panel was outdated and needed upgrading to support the new circuit.
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Since the building was divided into two units, noise levels had to be minimized for the neighbouring tenants.
Our certified technicians carried out:
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A dedicated electrical circuit with a 20A breaker in the main panel
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Installation of the indoor unit in the dining room, strategically placed to cover both the kitchen and living room
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Use of reinforced wall brackets with vibration dampers to avoid noise
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A discreet trench to run refrigerant lines along a side alley, protected from frost
The entire project was completed within two business days, with no service disruptions and a clean, polished final result.
Exceptional longevity: over 12 years of flawless operation
What truly sets this project apart is the extended service life of the system. More than 12 years later, this Lennox wall-mounted heat pump continues to heat and cool the home efficiently. The secret? Meticulous annual maintenance, performed by our team.
What we observed during maintenance visits:
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The indoor coil remained clean and corrosion-free
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The refrigerant pressure (R-410A at the time) remained stable
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No leaks or electronic failures, even after cold snaps reaching -28°C
The homeowner told us he never needed major repairs. Only preventive cleanings and one air filter replacement were required.
Comparing with other brands under similar conditions
We tracked comparable data on other installations of Gree, Fujitsu, and Mitsubishi wall-mounted heat pumps in Montréal during the same decade. While these brands are known for their reliability, the Lennox unit in Villeray stands out thanks to:
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Zero service calls in over 10 years
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Minimal loss in energy efficiency (estimated SEER still around 21 after 12 years)
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Superior cold-weather performance, thanks in part to its North American-engineered compressor
A reference case for homeowners in Montréal, Laval, and Longueuil
This project proves that the longevity of an HVAC system depends as much on the equipment’s quality as on the quality of the installation and long-term maintenance. At AirGreen, we know that every project is different. That’s why we tailor our approach to:
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The urban or suburban environment
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The building’s thermal envelope quality
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The client’s energy goals
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The available grants, such as Hydro-Québec’s LogisVert program (not available in 2012, but today we help clients get up to $2,172 in rebates)
Key takeaways from this case study
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A well-thought-out professional installation maximizes the equipment’s lifespan
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Lennox, often underestimated compared to Asian brands, delivers strong long-term performance
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Annual maintenance, often overlooked, plays a vital role in maintaining efficiency
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AirGreen provides comprehensive support, from selecting the right model to long-term maintenance
Customer testimonial
"I never imagined this little unit would last over 12 years without a single problem. It’s made it through the harshest winters. Honestly, hats off to the AirGreen team." – Mr. Lachapelle, homeowner, Villeray, Montréal
In conclusion: why choose AirGreen for your wall-mounted heat pump installation in Montréal?
We don’t just install systems. We design long-lasting solutions, adapted to Québec’s climate, your building, your budget, and your eco-friendly goals. If you're looking for a reliable, energy-efficient wall-mounted heat pump in Montréal, Laval, Longueuil, on the North or South Shore, trust our proven expertise.
Call us today for a free consultation or to schedule a maintenance visit for your current system.