What You Need To Know To Get Rid Of Drafty Air Leaks In Your Home

Drafts in your home can affect your heating bills. The primary locations for drafts, or air leaks, are cracks and anywhere there is thermal bridging. In this article you will learn about what these air leaks can do, how to find them, and what to do about them so you can keep your family warm and reduce your heating costs.

The Physics Behind the Drafts

Negative air pressure is created inside your home when heat rises to the top of your house but can't escape. This is called the stack effect. It causes cold air to get suctioned into your house from the foundation and through cracks, such as around your windows and doors. This suctioning of the cooler outdoor air into your home is the draft you feel when you sit beside a window in your home. It's also the draft you feel at the top of the stairs to your basement or crawl space.

DIY Test for Drafts in Your Home

You can hire a professional to do an energy audit of your home to see how much cold air comes through these leaks. But, if you just want to see where the drafts are coming from, you can do a quick test yourself using a lit incense stick. Here's how. 

  • Close the vents in your attic and foundation, as well as all the windows and exterior doors. If you have an interior door that leads to the basement or crawl space, seal it with duct tape because cold air naturally gets suctioned into your home from the lowest level.
  • Turn on the fans in your bathrooms and kitchen. With the fans going on full blast in your bathrooms and kitchen, it will pull the air from the inside of your home to the outdoors. The same amount of air that escapes will be replaced naturally by the negative air pressure and the stack effect. This occurs through cracks in your home's building envelope.
  • Take a lit incense stick and carefully walk around your home while paying attention to how the air flow makes the smoke move. When you notice the smoke drifting sideways, look in the opposite direction for a drafty air leak. Remember, the drafts are pulling into your home, which will push the incense smoke away in the opposite direction.
  • Use painter's tape to mark the locations of the drafts you found, or the general areas of them if you are not able to pinpoint them exactly.

Fix the Drafty Air Leaks

After the test, take a look around to see where most of the tape marks are. If they are generally located around windows and doors, you may want to consider replacing or sealing them. If the tape seems to be every 16-24 inches along the wall then it's likely you have thermal bridging, which means there are gaps in between the insulation and wall studs. The best way to fix this is to install continuous insulation to the exterior of your home. Continuous insulation can also help reduce or eliminate drafts around your windows and doors.

Ventilate Your Attic & Basement or Crawl Space

With the air leaks taken care of, you'll need to ventilate the attic and basement to reduce or eliminate negative air pressure and the stack effect in your home. The easiest way to do this is to make sure the vents are set to allow an equal amount of air movement out of the attic and into the basement or crawl space. 

Finding drafty air leaks in your home is easy with an incense stick. It helps you pinpoint where the drafts are coming from so you can eliminate them by sealing cracks and installing insulation.