January 3, 2023

How to detect cold air infiltration in your home

Brrr… Feel a draft of cold air at home? If all your windows and doors are closed, that could indicate a problem. You may have a cold air leak if there are areas of your home that stay cold even with the heat on.

Even a small air leak can make your house less comfortable and raise your heating bill. Read on to learn how to detect cold air leaks and fix them.

Why is it important to locate air infiltration?

Cold air leaks can make your home less comfortable. No one likes to sit beside a poorly insulated window. If cold air seeping in past the doorframe means less than total protection from the storm, it’s a good idea to fix it!

Comfort aside, it’s also a question of energy efficiency. Leaky windows let heat escape from the house. Your heating bill will increase as a result. According to CAA Québec, “Officials with Quebec’s Agence de l’efficacité énergétique (AEE) estimate that ‘typical Quebec homes lose about 30% of their heat because of hidden air leaks in various locations throughout the house.’”

Where to check for air leaks

Air leaks can occur throughout the home. Some areas are especially vulnerable to insufficient airtightness:

  • windows and frames
  • doors
  • exhaust vents
  • trapdoor to the attic
  • electrical outlets or wiring holes
  • around pipes and ductwork
  • where the foundation meets the walls
  • chimney
  • roof

Air infiltration may be caused by inadequate installation but it is usually due to aging of doors, windows, or caulking.

How to find cold air leaks

In cold weather, cold air leaks are easily found. A simple visual inspection may suffice to reveal that a door’s weatherstripping is worn out.

Here are some simple methods for finding other, less obvious places for cold air leaks.

Light a candle or a stick of incense and walk around areas where you suspect there’s a gap in airtightness. Drafts will make the smoke or flame dance.

Using the same principle, you can also hold out a tissue or a feather in suspected areas to look for signs of a leak.

It can help to turn on ventilation sources around your home to increase the air current: the fan above your oven (range hood), bathroom fan, clothes dryer, etc.

Another way to look for air leaks is with a powerful flashlight. Wait until it’s dark outside, and turn off all the lights.This method takes two people. One shines the light around suspected leaks, such as door frames, and the other watches on the other side to see whether light passes through.

How to fix air leaks

Repairing airtightness can be a simple fix. It may be enough to redo the caulking or replace the weather stripping. You can also use insulating plastic film on the windows in winter.

Note: improving airtightness may augment moisture in the house or walls. For serious air leak issues, it’s best to consult a specialist.

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See also:

5 signs of inadequate home insulation

How to insulate an existing home

10 simple tips to save on your heating bill

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