Stories & Features

15 ways to reduce condensation in your home

Image of condensation on the inside of a window
If condensation is collecting on windows in your home, especially in rooms on your upper floors, you should take measures to lower the humidity in your home.

Make mold, mildew and soggy window panes a thing of the past

Kathryn MacDonald

Some condensation is normal, but too much can affect your health and how comfortable you feel inside your home.

The average family produces about 10 litres (2.6 gallons) of moisture a day through simple, everyday activities such as cooking, washing dishes, washing clothes and taking baths or showers. This moisture in the air of your home turns into condensation when it comes into contact with a surface or object that's cold enough to chill it below what's called the "dew point." That's when the invisible vapour becomes visible droplets of water.

Too much moisture can lead to mold and mildew, which may cause allergies or lung problems. This can be a result of water leaks, flooding and high humidity.

Mold can produce nasty stains on your windowsills, walls and ceilings. It can also cause the paint to blister or peel both inside and outside your home, and your home can take on a musty odour. In extreme cases, that condensation can lead to rot and structural decay in wood-framed houses or buildings. Mold can grow on food, wood, paper, fabrics, drywall and insulation.

It can also be hidden, growing inside walls or above ceiling tiles.

Here are 15 ways to help reduce or eliminate condensation in your home:

  1. Check for any damp spots in your home, and fix any water leaks straightaway.
  2. Use kitchen fans when cooking.
  3. Run the exhaust fan in your bathroom during and after showering and bathing.
  4. Make sure vents lead outside for your clothes dryer, stove, kitchen and bathroom fans.
  5. Caulk around tubs and sinks to avoid water leaking into walls.
  6. Donate and clean out basement clutter to avoid creating areas for mold to grow.
  7. Ventilate your home by opening windows, weather permitting.
  8. Lower humidity levels to 50% in the summer and 30% in the winter. You can use a dehumidifier or air conditioner for this.
  9. Clean and disinfect items that hold water, such as air conditioners and dehumidifiers.
  10. Use paints on your home's exterior that allow moisture to pass through. Consult with your local paint speciality store to find what's best for your house gets too humid, such as when you're cooking, bathing, doing laundry or entertaining many guests.
  11. Use timers to control exhaust fans, allowing you to turn them on when needed without forgetting to turn them off.
  12. Leave a furnace fan on, if you have one, all the time at a low speed during warm and cold weather seasons. It helps to circulate the air through the house and reduces warm and cold spots.
  13. Add a fresh air duct with a variable damper to your heating system to allow a controlled amount of outside air into your home.
  14. Install a heat-recovery ventilator in combination with air sealing. This kind of venitilator can allow for fresh air ventilation while minimizing your energy bills, but is best suited for new construction or deep retrofit projects as it can be expensive to install.
  15. Replace old, single paned windows, which are most likely allowing a lot of cold air to get into your home, making you uncomfortable and causing a lot of condensation.

If you're looking at replacing your windows or installing a heat recovery ventilator, check out the Bonus Offer through our Home Renovation Rebate Offer where you can get $750 back for installing ENERGY STAR® windows or an ENERGY STAR heat recovery ventilator when you install three or more eligible upgrades at home. When considering this or any other upgrade, talk to an expert to find out what's best for your home.

For more tips on ways to decrease condensation, check out our tips to reduce condensation [PDF, 148 KB].

If you see mold, learn about what to do to get rid of it [PDF, 148 KB].

Kathryn MacDonald is a member of BC Hydro's community team.

Image of BC Hydro rep Kathryn MacDonald
BC Hydro community representative Kathryn MacDonald