In an energy-conscious household, an air leak can mean lost heat or cooled air, as well as a higher electric bill. There are many ways to locate air leaks in your home and steps you can take to seal your house.
For a more comprehensive procedure, you can hire a technician to conduct a blower door test which depressurizes a house to find the air leaks. Another advanced process involves an infrared camera that produces an image indicating exactly where the air is escaping.
First, however, follow some of these guidelines, and you will be able to locate a good portion of the air leaks without any expensive tools.
Consider Where Air Might Leak
The most obvious place to look for air leaks may be underneath doors, but there are many places as well. In an old home, the frames around doors and windows are often ineffective for containing air. Look to any place where one material meets another, such as mail chutes, dryer vents, the entrances for cables or faucets, and old brick, stucco or concrete walls and foundations.
If there are places in your home where brick meets wood, or some other combination of materials, you might check there as well. Remember that the substances used to adhere these materials often crack or separate around these surfaces.
Finally, single pane windows—especially those in old homes—are notorious for leaking air.
Detect the Air Leaks
You can depressurize your home without hiring a technician. On a cold, breezy day, turn off the furnace and shut all windows and doors. Turn on any exhaust fan in the house that blows air outside, like bathroom or stove fans.
Light a stick of sage or incense, carrying it around the house to areas of concern. Wherever you see the smoke being drawn out, you know you have an air leak.
You can also shine a light through bigger, more noticeable problem spots. Have someone else stand on the other side to confirm the leak.
Solving the Problem
Once detected, the ways to fix air leaks are as numerous as the possible locations for them. For smaller seepages, some kind of sealant may do the trick.
Treat leaks through single pane windows by fitting them with storm windows—both inside and out—or replacing them with modern energy-saving models.
Air loss from underneath doors may be solved with a draft guard. Other leaks may require a specific type of treatment. It really depends on where and how big the leak is.