Poor ventilation can seriously compromise your home’s health
At AirGreen, we know that many homeowners in the South Shore, Laval, or even Longueuil notice the same recurring issue each winter: excessive condensation on their windows. This common problem, often brushed off, is actually a symptom of a major imbalance in your home’s ventilation. Through a concrete example from our field experience in Boucherville, we’ll explain why this happens—and more importantly, how a properly installed air exchanger can solve it for good.
The real case: a newer home with poor ventilation
We were recently contacted by a couple living in a bungalow built in 2017 in Boucherville. Despite compliant insulation and modern double-glazed windows, they noticed large amounts of condensation on the windows every morning during winter—so much so that the window frames were starting to deteriorate. Indoor humidity levels regularly exceeded 60%, also causing persistent odors and a heavy air feeling throughout the home.
AirGreen diagnosis: windows crying, house suffering
Our team of HVAC installation specialists quickly went to the site to perform a full ventilation assessment. Using portable sensors, we identified:
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A complete absence of a mechanical air exchanger in the home.
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Poor air circulation between rooms, especially in the basement.
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Bathroom fans that were insufficient and rarely used.
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No permanent exhaust system in the kitchen.
Combined, these issues caused a buildup of humidity from daily activities (showers, cooking, laundry), which became trapped inside the house.
Proposed solution: a high-performance HRV air exchanger
We recommended installing a VENMAR AVS S10 130 CFM heat recovery ventilator, a unit perfectly suited for the home’s size (around 1,800 sq. ft.) and the South Shore climate. This model offers:
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130 CFM of controlled airflow, providing constant air renewal without over-ventilation.
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75% heat recovery efficiency, to maintain stable indoor temperatures.
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Washable MERV 8 filters, effective against allergens, dust, and common indoor pollutants.
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A smart wall-mounted control panel with automatic modes and humidity control.
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ENERGY STAR certification, making it eligible for LogisVert grants.
This unit is also completely silent, which was important to the couple who both work from home.
Installation steps: speed, cleanliness, efficiency
Our technicians completed the full HVAC installation in two days, including:
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Drilling through the exterior wall for intake and exhaust.
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Mounting the main unit in the crawl space, using anti-vibration supports.
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Connecting to the existing ductwork and balancing airflow per room.
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Training the client on how to use the system optimally.
We also installed motorized dampers in the bathrooms to enhance targeted extraction.
Results: no more condensation, just comfort
Just a few days after installation, the results spoke for themselves:
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Complete elimination of condensation on the windows—even during freezing temperatures.
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Indoor humidity stabilized at 45%, eliminating mold risks.
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Lighter, odor-free indoor air and improved comfort throughout the house.
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Lower heating costs, thanks to better heat distribution.
The couple expressed total satisfaction, saying they hadn’t realized how crucial ventilation was to well-being and protecting the home itself.
Why indoor humidity is such a problem
In winter, outdoor air is naturally dry. When this dryness isn’t balanced with a high-efficiency air exchanger, indoor-generated humidity accumulates. This excess moisture directly damages materials, wears down window seals, encourages mold growth, and harms respiratory health.
It’s important to remember that a well-ventilated home:
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Protects the building structure.
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Reduces the need for costly HVAC maintenance.
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Supports the occupants' health.
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Extends the life of appliances and household equipment.
AirGreen expertise: trusted, local support
At AirGreen, we’re out in the field every week across Montréal, Laval, Longueuil, and the North and South Shores, installing and repairing air exchangers suited to Québec’s climate. Our added value includes:
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Precise diagnostics, on-site or remotely.
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A carefully curated selection of the best HRV systems (Venmar, Fantech, Broan).
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Clean, certified installations, tailored to your lifestyle.
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In-depth knowledge of available government grants.
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Warm, professional, and transparent customer service.
Practical tips to avoid condensation on your windows
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Run your air exchanger continuously at low speed.
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Clean the filters every 2 to 3 months.
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Make sure your bathroom and kitchen fans are connected to the main system.
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Avoid drying clothes indoors without active air extraction.
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Have your ventilation system inspected every 2 years.
Smart ventilation = protected home
Condensation on windows is not inevitable. It’s a warning sign. With a proper air exchanger, you can not only eliminate it, but also improve your home’s health and comfort—while achieving significant energy savings.
At AirGreen, we help you take control of the air you breathe, with reliable, long-lasting solutions tailored to the real needs of Québec homes.