The Hidden Side of Heat Pumps: What 10 Years of AirGreen Fieldwork in Montréal Have Revealed

A decade of HVAC expertise uncovered: the truths wall-mounted and central heat pump systems have taught us in the field

At AirGreen, we’ve spent the last 10 years crisscrossing Montréal, Laval, Longueuil, the North Shore, and the South Shore to maintain, repair, and diagnose heating, ventilation and air conditioning (HVAC) systems — particularly wall-mounted and central heat pumps of all brands and sizes. This extensive field experience has given us a unique window into how these systems actually perform under Québec’s real-life conditions. What we’ve learned goes far beyond what manufacturers' brochures and promises tell you. Here’s what a decade of hands-on experience with heat pumps has truly revealed.

Improper installations: a more common issue than you’d expect

One of the most striking findings from our team is the high number of poorly executed installations, especially in residential areas of Montréal and Laval. Too often, we’re called to look at recently installed systems that aren’t heating properly or are consuming unusually high amounts of energy. In nearly 30% of these cases, the problem isn’t the heat pump itself, but a sloppy or non-compliant installation.

Real-world examples:

• In Saint-Léonard, a client called us about a Goodman central heat pump that stopped heating properly in cold weather. We discovered poorly insulated ducts, reducing the system's efficiency by 40%.

• In Laval-des-Rapides, a 12,000 BTU Gree Sapphire wall unit was undersized for a 900 sq. ft. ground floor. The result: the machine ran non-stop, causing premature compressor wear.

What we did: At AirGreen, we corrected the ductwork, recalibrated the system, replaced inadequate units, and most importantly, educated misinformed customers about proper sizing.

Neglected maintenance: the silent killer of performance

Another key issue highlighted by our HVAC maintenance services is the lack of regular unit cleaning. This isn’t just a matter of comfort — it’s critical for performance and durability.

Common cases we’ve seen:

• In Longueuil, we cleaned a Fujitsu wall-mounted heat pump that hadn’t been serviced in six years. The coils were clogged, cutting airflow by half.

• In Boisbriand, a customer complained of foul odors. Once we opened the unit, we found mold growing inside the drainage tray.

Our solution: Annual deep cleanings with high-pressure washing, disinfection, filter cleaning, pressure checks, and calibration of electronic components.

Surprising long-term insights from different brands and models

Thanks to our interventions on several thousand systems across Greater Montréal, we’ve had the chance to observe the true long-term performance of various brands.

What 10 years have taught us:

• Fujitsu KZAH R-32 heat pumps: Excellent mechanical reliability, but sensitive to voltage fluctuations in some South Shore neighborhoods.

• Gree Extrême and Sapphire models: Great cold-weather resistance, but their electronic boards are vulnerable to moisture if poorly protected.

• Goodman Air Handler R-32: Durable, but requires thorough coil cleaning to avoid performance drops.

• Bosch BIVA IDS Premium R-454B: Highly stable long-term performance, very quiet, but demands a perfectly sealed installation to avoid refrigerant leaks.

We always tailor our recommendations based on the building’s exposure, volume to be heated/cooled, and the customer’s actual usage.

The Montréal climate’s impact on system performance

Harsh winters and increasingly humid summers have a significant impact on heat pump performance.

Real examples:

• In Pierrefonds, a client reported excessive frost on their wall unit in January. The defrost system was poorly configured.

• In Brossard, blocked condensate pipes froze up and caused water infiltration into the wall.

AirGreen takes a preventative approach: We recommend insulated drain lines, elevated mounting brackets, protective housings, and fine-tuned defrost mode settings depending on the region.

What most clients don’t know... but absolutely should

After a decade of working closely with homeowners and property managers, here are the key facts we emphasize with every client:

• A heat pump isn’t a standalone system: it’s part of a whole ecosystem (insulation, ventilation, humidity).

• An oversized unit is just as problematic as an undersized one.

• Annual HVAC maintenance is crucial to keep warranties and performance intact.

• The Hydro-Québec LogisVert program can cover up to $2,172 depending on the model and location, but the eligibility criteria are strict.

Top 5 mistakes to avoid, according to AirGreen

1. Choosing a unit based solely on price or brand name.

2. Skipping maintenance for years.

3. Ignoring insulation or duct quality.

4. Installing a wall unit in shaded areas without considering airflow.

5. Not hiring a certified (and experienced) installer.

Why choose AirGreen: our added value after 10 years

We’re not just another installer. We’ve seen what’s behind the scenes, fixed hundreds of bad installations, trained our teams on dozens of brands, and most importantly, we focus on a comprehensive and long-term HVAC approach.

Our expertise is backed by:

• Thousands of cleaning, maintenance, and repair calls in Montréal, Laval, Longueuil, North Shore, and South Shore.

• Total transparency about real-world equipment performance.

• Personalized support for every customer — from initial assessment to after-sales service.

Trust the ones who’ve seen what spec sheets don’t reveal.