Condensation on windows occurs when warm, humid air comes into contact with a cool surface, such as a windowpane. The moisture in the air then condenses into water droplets on the surface. This is why condensation is more common in the winter when the outside air is cold and dry, and the indoor air is warm and humid due to everyday activities like cooking, bathing, and breathing. High outdoor humidity, little or no wind, and a clear night sky can also cause exterior window condensation. Excessive humidity is the main cause of window condensation. While condensation on windows can be bothersome and obscure your view, it is typically not concerning and can even be a sign that your windows are forming an airtight seal, reducing air leakage and keeping the moisture inside your home. However, persistent indoor window condensation can lead to the growth of mold or mildew, which thrive in damp environments and on organic materials, like wood. To reduce condensation on your windows, you can try the following:
- Increase ventilation by opening windows or using exhaust fans in bathrooms and kitchens to expel warm, moisture-laden air to the outside.
- Use a dehumidifier to reduce the humidity level in your home.
- Install storm windows or replace old windows with energy-efficient ones that have low-e coatings to keep the interior glass surface warmer.
- Use weather stripping and caulking to seal air leaks around windows and doors.
- Keep blinds or curtains open during the day to allow warm air to circulate around the windows.
