Optimizing Your Home Ventilation: A Crucial Issue for Québec Winters
In winter, ventilation is often overlooked, considered secondary compared to heating. Yet at AirGreen, we know just how much poorly managed ventilation can affect indoor comfort, drive up energy bills, and lead to premature wear on HVAC systems. On the North Shore, where temperatures can drop drastically, these mistakes come at a high price — literally.
In this article, we’re sharing 7 costly mistakes we’ve repeatedly encountered during our service calls in Blainville, Boisbriand, Terrebonne, Mascouche, and other towns north of Montréal. For each mistake, we explain how AirGreen provides practical solutions based on real residential ventilation projects.
1. Turning Off the Ventilation System to Save Energy: A Bad Idea
This is a persistent myth: shutting down or lowering your ventilation system in winter supposedly saves electricity. In reality, this leads to a buildup of humidity, mold, and indoor air pollutants. The result: poor air quality, condensation on windows, and potentially structural damage to your home.
Real-life example – Lavaltrie, Winter 2024: a client turned off her HRV for three months and we had to perform an emergency service to treat a significant mold outbreak behind her basement walls. Our solution: replacing it with a VENMAR EVO5 250 HRV, calibrated to her home size and lifestyle, featuring integrated humidity sensors.
2. Relying Only on Kitchen or Bathroom Fans
Spot exhaust fans (range hoods, wall vents) have their place, but they can never replace a true centralized ventilation system. An HRV (Heat Recovery Ventilator) or ERV (Energy Recovery Ventilator) ensures efficient air exchange — removing stale air and bringing in fresh air while retaining indoor heat.
AirGreen project – Sainte-Thérèse: a family used only their kitchen hood for ventilation. The outcome: poor air distribution, lingering odors, and excess humidity in the bedrooms. We installed a Fantech FLEX 100H ERV, a compact and energy-efficient solution ideal for smaller spaces.
3. Neglecting Filter Maintenance in Winter
In winter, ventilation systems run continuously or much more frequently. Filters get clogged faster, especially due to urban pollution, pet dander, and cooking fumes. A dirty filter reduces airflow, increases energy use, and can damage the motor.
At AirGreen, we recommend preventive HVAC maintenance at the beginning and end of winter, including duct cleaning, HEPA or foam filter replacement, and static pressure calibration.
4. Installing a Ventilation System Without Calculating Airflow
A frequent mistake we see is installing a ventilation unit that’s either too powerful or too weak, with no proper airflow calculation. This creates pressure imbalances, air leaks, and heat loss.
Example – Boisbriand, December 2023: a client installed a secondhand HRV (wrong size, 300 CFM capacity for a 1000 ft² home). We conducted a thermal imaging assessment, then replaced it with a VENMAR AVS E15 ECM HRV, using insulated flexible acoustic ducts to maximize quiet performance and comfort.
5. Poor Placement of Ventilation Registers
Too often, exhaust or supply registers are installed in the wrong locations, which disrupts proper airflow: they’re either blocked by furniture, misaligned, or placed in ineffective areas.
AirGreen tip: registers should be located strategically – near humidity sources (kitchen, bathroom) and opposite fresh air intakes to promote airflow. When in doubt, we use portable anemometers to verify actual airflow in each area.
6. Ignoring the Balance Between Ventilation and Heating
An efficient ventilation system must be perfectly balanced with the heating system, especially in winter. If not, it can cause depressurization or overpressurization, leading to heat loss or even safety risks (e.g., combustion gas backdrafts).
Real case – Saint-Eustache, January 2025: a gas furnace-heated home faced a backdraft risk due to an overly powerful ventilation system. We rebalanced the setup by installing a pressure controller and adding a motorized damper to modulate airflow automatically.
7. Overlooking Available Grants for Ventilation Systems
Many residents are unaware that subsidies are available to help upgrade ventilation systems throughout the Greater Montréal region. On the North Shore, municipal and provincial programs can cover up to 30% of the costs in some cases.
At AirGreen, we support our clients through every step of the application process, whether it’s for LogisVert, RénoClimat, or local incentive programs. In 2024, over 60% of our clients in Repentigny and Lorraine received financial assistance for their HVAC installation.
How AirGreen Helps You Avoid These Mistakes
With over 15 years of experience in residential ventilation on the North Shore, our team understands every climatic and technical challenge unique to Québec homes. Our services are customized, professional, and precisely planned, whether for a century-old house in Saint-Jérôme or a modern semi-detached in Mirabel.
Our residential ventilation services include:
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Installation of HRV/ERV heat recovery systems
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Balancing existing HVAC systems
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Complete HVAC maintenance (cleaning, filter replacement, system calibration)
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Technical advice on models, BTU, airflow rates, and recommended brands
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Assistance with grant applications
Trust AirGreen for a Ventilation System That’s Efficient, Affordable, and Winter-Ready
Avoid the costly mistakes that hurt your comfort and your wallet. Our HVAC experts serve the entire North Shore, from Laval to Saint-Colomban, offering fast, accurate, and transparent service.
Contact us today for a free evaluation or to learn more about energy-efficient ventilation systems that are perfectly suited to your home.