Educational Consumer Tips

Condensation on Windows

Author: Better Business Bureau

Occasional water on your windows during winter is nothing to worry about. However, excessive condensation can damage your window frames and sills in addition to your window coverings and the dry wall, plaster, paint or wallpaper surrounding your windows. During the winter, your windows will generally be cooler than the rest of the room. When the warm air in the room comes in contact with the colder window and frame, it immediately cools down. Since warm air holds more moisture than cold air, as the air against the window cools down, it can't hold the same amount of water vapor. The excess moisture condenses into water, frost or ice on the window and frame. This occurs more frequently during the winter because of the extreme difference between the inside and outside temperatures. All homes will have occasional condensation from things that add moisture to the air such as cooking, showering and venting the exhaust from a dryer into the house. Newly constructed or remodeled homes may have condensation from the moisture in the building materials which should disappear after the first heating season. You may also see temporary condensation following a humid summer when houses absorb moisture. The house should dry out after a few weeks. You can correct a condensation problem by reducing the humidity in your home. You can do this by lowering the setting on your humidifier if you have one or by increasing your ventilation by controlling the amount of moisture you release into the air. When cooking or showering, use exhaust fans or open a window slightly. When drying clothes, don't vent the dryer into the house since this air holds a lot of moisture. To help dry out the air, open blinds and drapes during the day. You can also reduce window condensation by insulating your existing windows or installing better-insulated windows and frames. Insulated windows and frames that don't transmit the cold outside temperature very well will decrease the difference in temperature between the window and the air in the room. In some cases, however, you may notice more condensation after installing new windows that fit tighter than your old windows because they allow less airflow around them. If this occurs, you should take steps to reduce the humidity in your home.