What to Do if Your Windows Are Leaking Air
Last edited
Author
Andrew Giermak
Solar and Electrification Writer and Editor
Editor
Andrew Blok
Electrification and Solar Writer and Editor
Drafty windows letting air in or out of your house can be a year-around problem. If you think your heating and cooling is running too much or you notice higher utility bills, your home’s windows could be one reason. Leaky, inefficient, or simply older windows can lead to uncomfortable temperatures and conditions inside your home. Leaky windows can also mean wasted energy, which is wasted money.
We’ll walk you through the problems which can result from leaky windows, steps you can take to repair the leaks and drafts, and what to consider if you need professional repair or new windows.
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Problems With Leaky Windows
Leaky windows can be a significant detriment to your comfort and your home’s energy efficiency, which can result in higher energy bills.
Drafty windows allow air to move from your air-conditioned interior to the exterior. This leads to cold spots in the winter and hot spots in the summer, making it difficult to maintain a consistent, comfortable temperature throughout your home.
When your home loses heat in the winter or gains heat in the summer, your heating and cooling works harder and uses more energy.
The US Department of Energy estimates that heat loss or gain through windows is responsible for 25-30% of a home’s total heating and cooling energy use, with air leaks being a major contributor. Energy-efficient windows lead to lower monthly utility bills.
Why Do Windows Leak Air?
What causes leaky, drafty windows? It’s usually the seals and frames of a home’s windows.
One major cause is old, worn, or poor sealant around the window. Over time, seals and caulk can wear and crack or the window frame can slowly warp and create a gap between it and the wall. Adding or updating the caulking or weatherstripping around windows is one project that can make a positive difference in energy efficiency and comfort.
Air can also leak through the window if the seal between the glass panes in double- or triple-pane windows fails.
If the original installation was not done well, a window may not be properly sealed or secured into the home's building envelope, leaving hidden gaps. These leaks can waste energy.
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Detecting Window Air Leaks
Other than having leaks or drafts so bad you can definitely feel it, how else can you identify leaky or inefficient windows?
The most precise way is with a home energy audit. There are energy audit steps you can do yourself such as checking insulation levels, checking air filters, replacing incandescent bulbs with LED light bulbs, checking caulking and weatherstripping, and checking temperatures around your home on your own.
A professional home energy audit typically includes a blower door test, in which a powerful fan depressurizes the house to clearly detect air leaks. Other technology, such as a thermal imaging camera, can be used to find heat gain and loss anywhere in your home envelope, including windows. A professional energy audit can also check appliances, insulation, ductwork, and utility bills to find areas of waste.
How energy efficient windows operate to keep heat in or out, depending on the season.
Fixing Window Air Leaks
A good first check for fixing leaky windows is the caulking or weatherstripping to ensure the seal around your windows is sound. Caulk and seal all the permanently-closed gaps around window frames, and add or update the weatherstripping on the moveable, openable parts of your windows.
Another step to stop heat transfer is to use window coverings like curtains, shades, blinds, or even trees and shrubs to provide layers and barriers to drafts, wind, and natural solar heat.
If a window is old, single-pane, or visibly damaged, or the sealing is too damaged to repair, replacing them with new energy-efficient windows is the best solution. New windows will give you benefits in comfort, safety, energy efficiency, and cost savings. Installing Energy Star-certified, double-pane windows can give you the energy efficiency you’re looking for with all the other benefits of modern windows for your home.
If you’re looking for more ways to save energy, check out Palmetto’s Savings Maximizer to see all the ways Palmetto may be able to help.
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Frequently Asked Questions
When should I stop trying to fix a window and call a professional?
You should call an expert if you see fog or moisture between glass panes, which typically means there’s a broken seal. Also, if a frame is warped or rotting, or you have a leak but can’t determine where it’s coming from, it’s likely best to hire a professional.
What is the difference between caulking and weatherstripping?
With windows, caulk is used for stationary gaps, like the space between the window frame and the wall. Weatherstripping is flexible and is used to seal movable joints, allowing the window to still open and close while preventing heat gain and heat loss.
