When the temp gets around 35 or below, my windows sweat really bad. It freezes around the frame and I have to scrape it off. Our home is 11 years old, but the windows have done this since it was new. My husband says it is the gas fireplace that we use that does it. I read that too much humidity would cause it, would a dehumidifier help? I have to go around every day and dry the windows. Can you help? -Carol
We get a lot of questions about windows sweating in the winter. Here’s what’s happening and why.
When air warms, it expands which allows it to hold more moisture. As it cools down, it contracts until it reaches the saturation point and releases this excess water in the form of condensation.
Common daily activities in your home—such as cooking, showering, using unvented gas heat, and even breathing—add moisture to the air. When this warm humid air comes in contact with cold window glass, it cools and condenses.
To reduce this problem you need to either lower the amount of moisture in the air inside your home, or prevent it from coming in contact with cold surfaces. Here are some suggestions that might help:
- If you are still having problems, consider installing a dehumidifier.