Sealing Air Leaks
Sealing air leaks in your home is one of the most effective ways to improve energy efficiency, lower heat bills, improve the comfort of your home and reduce greenhouse gas emissions.
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Sealing Air Leaks
Sealing air leaks in your home is one of the most effective ways to improve energy efficiency, lower heat bills, improve the comfort of your home and reduce greenhouse gas emissions. Air leakage can represent 25 to 40% of the total heat loss in an older home. As a result, sealing leaks is usually the single most cost-effective upgrade you can make to an older home.
Air leaks can occur anywhere in the house, from the basement to the attic. Common leakage points include gaps under doors and around windows, foundation cracks and unsealed fixtures, such as dryer or ventilation outlets connecting to the outdoors.
Common Sources of Air Leaks
Locating Air Leaks
Homeowners can do their own assessment of air leaks by looking in common spots and either feeling for cold air or holding a tissue or smoke pencil to see if air is moving. This is best done on a windy day when air movement will be greatest and easiest to detect.
Alternatively, homeowners can have a certified energy advisor perform a "blower door test" to locate air leaks. A blower door is a powerful fan that is mounted into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. These tests take about 30 minutes to complete, and determine the air leak rate of a house or building.
To find out more about locating a home energy advisor in your area, visit the takeCHARGE website.
Sealing Air Leaks
Sealing air leaks can cost from between less than $100 to upwards of $1,000, depending on the size of the job and whether you do it yourself or hire a contractor. The most cost-effective solution is to start by sealing the largest holes, followed by sizable cracks and penetrations, and then smaller leakages.
Some of the easiest air leakages to detect and fix are those around windows and doors. Caulking can easily be applied to cracks around window frames, doors and along the tops of baseboards, though in the latter case it may be worth first removing the baseboards and blocking the source of the leaks. Don't forget to also caulk along cracks and gaps on the outside of the house.
Attic hatches, plumbing stacks, chimneys, kitchen and bathroom exhaust fans, recessed light fixtures and electrical wiring can also be sealed, but care must be taken around hot spots, such as lights and chimneys. When sealing air leaks, homeowners should be mindful to ensure their house stays properly ventilated.
In this section
Insulation
Windows and Doors
Sealing Air Leaks
Ventilation