When a poor-quality air exchanger threatens your comfort and health
At AirGreen, we’ve seen firsthand the real consequences of an air exchanger that’s poorly chosen, improperly installed, or simply defective. This isn’t just about numbers or technical diagnostics — we’re talking about entire families living daily with the effects on their quality of life, respiratory health, and energy bills. All across Montréal, Laval, Longueuil, the North Shore and the South Shore, these problems are far more common than you might think.
In this article, we’ll share with you real-life cases from clients we’ve recently helped. You’ll see how common mistakes related to HVAC installation or poor air exchanger selection can have long-term impacts. We’ll also showcase our thorough, expert approach to fixing the problem and restoring healthy indoor air to homes across Québec.
Case #1 – Montréal (Rosemont): hidden humidity poisoning the winter
In a typical duplex in Rosemont, a family of four was suffering from chronic respiratory issues. The culprit? An air exchanger installed ten years ago, never maintained, and completely undersized for the home’s surface area.
Symptoms:
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Heavy condensation on windows during winter
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Mold growing on bed frames and inside closets
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Constant chill despite regular heating
AirGreen’s Diagnosis:
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Non–ENERGY STAR certified air exchanger
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Duct network clogged with dust
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No air returns in the bathroom or kitchen
Solution:
We removed the outdated unit and installed a Venmar AVS Constructo 2.0 HRV, certified for homes up to 2100 sq. ft. New rigid ducts were laid, and a wall-mounted digital control panel was added for day-to-day management.
Result: Within just three weeks, the ambient humidity dropped from 68% to 45%, health symptoms eased, and the family’s heating bill dropped by 18% thanks to improved air circulation.
Case #2 – Laval (Sainte-Rose): the hidden surprise in a brand-new home
A young couple built their dream home on the North Shore, assuming that new construction automatically meant proper ventilation. Yet only six months in, stale odors filled the house, and their infant was developing recurring bronchiolitis.
Our team’s assessment:
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The builder-installed air exchanger was a low-efficiency model with no heat recovery
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No smart system or home automation compatibility
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CO₂ levels in the baby’s room were over 1400 ppm
Our intervention:
AirGreen installed a Lennox L-Series Wi-Fi ERV with energy recovery and mobile connectivity. We added humidity sensors in the bedrooms and connected the unit to their smart thermostat.
Result: Indoor air quality quickly returned to normal. Humidity now stays under 50%, odors disappeared, and the unit is fully controllable via smartphone.
Understanding the consequences of a bad air exchanger
1. Health risks
A bad exchanger fails to renew indoor air properly, increasing concentrations of pollutants, allergens, radon, and mold spores.
2. Excess or insufficient humidity
Poor humidity control causes condensation, material damage, and long-term structural deterioration.
3. Overheating or energy loss
Without heat recovery, incoming air is cold in winter, hot in summer — which forces your heating or cooling system to work twice as hard.
4. Comfort issues
Too much cold air, not enough fresh air, uneven distribution across rooms — a poorly calibrated exchanger undermines your comfort.
How AirGreen resolves these issues
Step 1: Full inspection
We analyze your indoor air quality, the existing ventilation system, duct layout, airflow rates, and your home’s configuration.
Step 2: Customized recommendation
We propose a model tailored to your square footage, lifestyle, and HVAC setup, with eligibility for LogisVert grants where applicable.
Step 3: Professional installation
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Safe removal of the old air exchanger
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Installation of a new unit with an optimized duct network
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Smart home integration and system calibration
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Full training on maintenance and control settings
Common mistakes to avoid
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Choosing the cheapest model without evaluating your real needs
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Hiring a contractor without HVAC expertise
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Skipping regular HVAC maintenance
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Ignoring warning signs: humidity, odors, discomfort, fatigue, mold
Why trust AirGreen?
Our team of certified technicians works in every kind of home — century-old townhouses, triplexes, new condos, suburban homes. Our mission isn’t to sell a product, but to fix the air you breathe, once and for all.
With hundreds of successful air exchanger installations completed across Montréal and surrounding areas, we’ve seen the worst — and we know how to turn it into long-term success.
Key Takeaways
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A faulty air exchanger can cause serious health, comfort, and energy efficiency problems.
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Our clients in Montréal, Laval, Longueuil, the North Shore and the South Shore have lived through it — and their stories serve as a warning.
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At AirGreen, we assess, replace, and install durable, certified, smart solutions tailored to your home.
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You may qualify for HVAC-related grants to help finance a high-quality air exchanger.
Contact us today to schedule a free inspection of your air exchanger system. It might save you from major headaches.