Improve indoor air quality

Learn how you can improve your home’s indoor air quality.  

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Reduce air contaminants at the source

The most effective way to reduce indoor air pollution is to remove or reduce the source of contamination.


Make your home smoke-free by banning all tobacco products.

Dampness, water leaks and mould

Control humidity levels to avoid having too much humidity in your home. Too much humidity can cause mould to grow.

If you find mould, remove it yourself if it covers a surface area of less than 1 square metre. Remove mould on smooth surfaces with soap and warm water. There is no need to use bleach.

If mould cannot be removed from a surface easily, materials will need to be replaced. If the mould covers a bigger area, hire a professional to get rid of it.

You can reduce humidity by following these steps.  

  • Fix leaks immediately.
  • Check hoses and connections for leaks and repair as needed.
  • Repair or replace cracked or damaged tile, grout and caulking around:
    • tubs
    • sinks
    • showers
  • Check plumbing pipes for condensation. If found, dry the pipes and seal with foam insulation.
  • Use a bathroom or kitchen exhaust fan when showering or cooking to reduce humidity. Keep the fan on for at least 30 minutes afterward.
  • Use a dehumidifier to remove water from the air, especially in the summer. Remove water from dehumidifiers when not in use so bacteria do not grow.
  • Remove water and anything wet immediately from your home if you have a flood. Dry out the area and any wet furnishings within 48 hours to prevent mould growth.
  • Keep curtains and blinds open to prevent condensation from forming on windows. Dry your window frames and sills daily if condensation is visible.
    • Condensation on windows may indicate low ventilation or high humidity in your home.

When washing or drying your clothes:

  • hang laundry outdoors to dry when possible
  • seal the joints in the dryer duct with foil tape
  • make sure that water flows directly into the laundry sink or drain
  • make sure your dryer vents to the outside and that it is not blocked

When storing items in the basement, use plastic bins with lids instead of cardboard boxes.

When cooking:

  • cover pots with a lid
  • use the exhaust fan
    • cook on the back burner so the fan can do a better job of lowering humidity

Household appliances

Make sure fuel-burning appliances are installed, maintained and working according to manufacturers’ instructions. Have a qualified professional inspect them yearly, including chimneys and flues. These appliances can include:

  • gas water heaters
  • gas or oil furnaces
  • gas or wood stoves
  • gas or wood fireplaces


Cooking on the back burner and using the exhaust fan will help reduce particles and gases.

Follow these 3 tips for exhaust fans.

  1. Check the fans to make sure there is enough air movement.
  2. Make sure they are vented to the outside and not into the attic.
  3. Make sure nothing is placed in front of outside vents.

Activities that take place in an attached garage

Avoid idling your car, gas-powered lawnmower or snowblower in your garage. Pollutants can enter your home from the garage whether the garage door is open or closed.  

House cleaning

Regular cleaning using a mix of methods can help improve indoor air quality.

  • Clean floors with a damp mop or cloth.
  • Clean the lint tray every time you use the dryer and check for lint buildup on the outside vent.
  • Use a mattress and pillow protector. Also vacuum mattresses and wash sheets once a week in hot water.
  • Vacuum often. Install a central vacuum that is vented outdoors. You can also use a vacuum with a high-efficiency particle air (HEPA) filter that traps small particles .

Improve ventilation

Ventilate your home by making sure there is good air circulation and heat flow. You can do this by:

  • leaving interior doors open
  • using bathroom and kitchen fans
  • keeping baseboards or heating vents clear of furniture
  • opening windows and doors when outside conditions are not smoggy
  • keeping beds, bedding and furniture away from outside walls to allow enough air and heat flow around furnishings
  • using a mechanical HVAC (heating, ventilation and air conditioning) system in your home with a filtration system built into the duct work
    • replace or clean the filter as per the manufacturer’s instructions

When renovating, open the windows. Also make sure there is enough ventilation during major projects like:

  • cleaning
  • painting
  • varnishing
  • home improvement

Filter the air

Filtering the air can reduce some indoor air pollutants. But air cleaning is rarely effective on its own, and should be used alongside:

  • improving ventilation
  • reducing contaminants at the source

Portable air cleaners, particularly HEPA filters and electrostatic precipitators, can reduce some air contaminants. HEPA filters collect particle pollutants with a fine filter. But electrostatic precipitators collect pollutants with electrostatic energy, which causes pollution to stick to the filter.

Some air cleaners with electrostatic precipitators may also produce low levels of ozone, which can irritate the lungs. Ozone generators are sometimes marketed as air cleaners, but they are not recommended in homes.

Air cleaners can be effective in removing particles but most do not remove gases.

If indoor air quality does not improve

Some people have more options for improving their indoor air quality than others.  If you live in a multi-unit residence and have followed the listed actions without seeing an improvement:

  • talk to the building owner or management
  • check with your provincial or territorial government for information on the owner’s responsibilities and your rights as a tenant
  • check with your municipal government, as some municipalities may have by-laws on acceptable standards for rental properties
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