Tips for reducing energy consumption at home
Installing an efficient ventilation system in your home
Ventilation helps maintain good indoor air quality in a home. It contributes to the comfort and health of its occupants.
Role of a mechanical ventilation system
A mechanical ventilation system allows air from the home to be extracted outdoors, while also bringing in outdoor air.
Air extraction serves to remove:
- odours;
- excess humidity;
- pollutants contained in the home’s ambient air.
The introduction of outdoor air replaces stale indoor air with fresh air.
These two simultaneous actions ensure that the indoor air you breathe is regularly renewed.
Insufficient ventilation inevitably causes excess humidity resulting from showers, baths and cooking activities.
Excess indoor humidity in a home can lead to several problems:
- condensation on windows;
- premature deterioration of the home;
- growth of mould that can be harmful to your health.
Inadequate or deficient ventilation can also increase the concentration of contaminants (chemical and biological) in the air. For example, intensive DIY projects, furniture stripping, the use of combustion appliances, or other similar activities can rapidly degrade indoor air quality when ventilation is insufficient.
To reduce indoor air contamination, try to limit the sources of indoor pollutants. Storing large quantities of paint or cleaning products is a common and easily avoidable source of contamination.
Problems caused by excessive ventilation
Excessive ventilation effectively removes contaminants from the air but also has drawbacks.
An oversized system will, in winter, bring in large amounts of cold, dry air into the home. This can cause discomfort from cold drafts, significantly higher heating costs, and health problems such as dry eyes or nosebleeds.
In short, the selected ventilation system must strike a balance between efficiently removing pollutants and stale air, and ensuring a controlled supply of outdoor air to maintain both comfort and occupant health.
Required ventilation systems in a home
Installing a ventilation system is a necessity in almost every house. To ensure that it suits each home’s specific conditions and needs, it should be designed by a qualified professional in accordance with the requirements of the Québec Construction Code.
A typical ventilation system in a new home includes:
- A heat recovery ventilator (HRV), which simultaneously extracts and supplies air in the home. In winter, the HRV recovers heat from the exhaust air and transfers it to the incoming air. Air is usually extracted from one or more bathrooms and outdoor air is supplied to the living room, bedrooms and regularly used closed rooms;
- A range hood, which exhausts cooking fumes directly outdoors;
- A stand-alone bathroom exhaust fan, which removes moist air from the shower and odours from the toilet. A stand-alone fan is used when the HRV does not extract air from the bathroom;
- A duct network, which allows air to circulate between ventilation devices, rooms and the outdoors. Rigid, airtight ducts are preferable, as air flows more easily through them than through flexible ducts.
How to choose a ventilation unit
- Assess the air-exchange rates required for your home and select a unit capable of extracting and supplying air at those rates.
- Have the airflow rates measured and balanced at installation.
- Choose a heat recovery ventilator (HRV) whenever possible—it will help keep your home’s energy costs at a reasonable level. Note that installing an HRV is now mandatory for all new constructions in Québec.
- Ensure that the unit and ductwork are always accessible for maintenance and cleaning.
- Use rigid, airtight ducts and keep the duct network in good condition.
- Always have the actual airtightness of your home evaluated by an expert before purchasing and installing any ventilation equipment.
Financial assistance for a heat recovery ventilation system
Through the Rénoclimat government program, you may be eligible for financial assistance for the installation or replacement of a heat recovery ventilation system.
Be sure to meet all program eligibility criteria before submitting your application.
Radon presence
Special attention should also be paid to the presence of radon in the soil.
Radon is a naturally occurring gas in the ground that, at high concentrations, can greatly increase the risk of lung cancer. When high radon levels are detected, an independent fan connected to a duct system venting outdoors is an effective way to reduce radon concentrations in a home’s basement.
Visit the Government of Canada’s website—Testing your home for radon—to obtain a radon test kit or locate a certified radon-measurement professional.
Last update: November 5, 2025