Causes of Condensation

Warmer air contains more moisture than cooler air and condenses when coming in contact with a colder surface. Too much moisture in the air causes the condensation to accumulate, forming water droplets on windows. Because the windows are generally the coolest area in the house, the excess moisture in the air is drawn to the cooler air of the windows and water forms there. This may not necessarily be an indication of leaky windows, but actually could be from too much humidity in the house.

Excess Humidity

Three key verbs apply when alleviating excess moisture problems: insulate, ventilate and tighten, according to the Minnesota Office of Energy Security. A hygrometer is an instrument that measures levels of humidity. In the winter, suggested humidity levels for your home are somewhere between 15 and 40 percent, dependent on the outside temperature. Anything over 45 percent is considered high humidity and can lead to condensation problems. Washing and drying clothes can create additional humidity in the air, as can cooking and showering. If you have a number of houseplants, they may contribute to excess humidity in the air.

Sealing and Insulating

Air leaks potentially cause condensation as warm air meets cool air that comes from the leakage. Check the attic to be sure there is adequate insulation and that all plumbing and electrical vents are properly sealed. Check caulking around windows and doors for any leaks, and replace weather stripping and seal up gaps in window panes as needed. Moisture may also be drawn up from the basement and escape through the attic, so it is important to tighten all leaks.

Ventilation

Proper ventilation is an aspect of consideration in regard to condensation. As long as you have two types of air currents flowing through the house, warm and cool, you are going to have a condensation problem. Ventilations in high humidity areas such as the bathroom, laundry room and kitchen eliminate excess moisture from the air. However, fans in these areas should not be running longer than about 15 minutes or all you are doing is releasing heated air. Also, ventilation works both ways; to remove excess moisture and bring in fresh air to replace it and also to keep an appropriate air circulation cycle.