With weather dipping down into the 20 degree range, you may be noticing a chill caused by drafts in your home. Doors and windows are some of the most common places people notice drafts. Beyond being uncomfortable, drafts in your home have a major impact on your energy costs. So, let’s explore how they affect our home, how to find them, and how to fix them.
Based on the simple principle that heat rises, every home has a natural flow of air leaking out the top of the house and being drawn in the lower portions of the home. This principle is referred to as “stack effect” or “chimney effect”. Although this occurs 365 days a year, the colder it is outside the more rapidly air escapes from your home. These drafts can make a major impact on both your home’s comfort, as well as, its efficiency and air quality. When air leaks out the top of your house, exactly the same amount of outside air will be drawn in. This means your heating and cooling system has to work harder to condition outside air that is leaking in. It also means that you may be drawing in a lot of air from your crawlspace, which can have mold in it and negatively impact your air quality. Sealing up the drafts in your home can save 10%-20% on your heating and cooling costs and significantly improve your home’s air quality.
Finding the air leaks in your home can be tricky since there can be hundreds of them throughout your home. On a very cold day you may be able to identify the major air leaks in your home by feeling for cold drafts. The most effective way to identify air leaks is by using a blower door system. This is a fan system that is set up in an exterior door and blows air out of the house. A negative pressure is created inside the home, which pulls outside air in and magnifies normal air leaks to make them easier to identify. Using an infrared camera, we can capture images that show exactly where air is leaking into the home. This test will often uncover major air leaks that you never would have known about. Common air leaks are in the ducts system, around plumbing and wiring penetrations, attic access stairs or doors.
Stopping drafts in your home requires the detailed work of sealing up each accessible air leak. To do this it may require moving the insulation to seal leaks in the attic, installing an attic stair cover, caulking around windows, and replacing door weather stripping. Depending on each air leaks size and location, we will use different products. For air leaks in the attic or crawlspace we will usually use expandable foam to make them air tight. For air leaks inside the home we will use paintable caulk. The key for air sealing to be effective is to be detailed and get as many large and small air leaks as possible. Tightening up your home is a wise investment because it will make your home more comfortable, healthy, and efficient.