How to Prevent Condensation on Interior Windows

Check your windows carefully. The edges of the windows should be free of cracks or breaks in the glass seal. The caulking on the outside of the window frames should also be checked. Caulking is a waterproof sealant that is necessary for preventing condensation on interior windows.

Make sure your home is properly ventilated, particularly in rooms where the windows tend to accumulate a lot of condensation. Ventilation allows dry air to flow so moisture doesn't build up and cause condensation. Be sure nothing is obstructing any vents in your home, and make sure the vents in your attic and crawl space are opened.

Install exhaust fans and vents around your home, including in the bathroom, kitchen and laundry room, if they don't already exist. Run the exhaust fans longer than you normally do, about 15 to 20 minutes longer, to help prevent condensation. The vent for your clothes dryer should be well sealed. Avoid dryer vents that direct hot air into the main house.

Do not block fresh air intakes. Homeowners sometimes block these in an attempt to reduce the loss of heat from inside the home; however, this practice will disrupt air flow and cause a buildup of condensation on your interior windows.

Use a ceiling fan or portable fan to circulate the air in your home. Cool air tends to lead to more condensation on interior windows, and air becomes cooler at a faster rate when it's motionless, as opposed to being circulated.

Keep curtains, blinds and other window treatments raised either during the day or at night. Window treatments keep air from reaching interior windows, which can cause a buildup of condensation.

Be sure your home is properly insulated, particularly your attic, crawl space, outside window frames and closets. A common sign of excessive moisture on insulation is discoloration.

Avoid purchasing a vent-free fireplace. When gas logs are burning, they create a great deal of water vapor that will remain trapped in your home if you have a vent-free fireplace, as opposed to a fireplace that allows water vapor to escape through the chimney. (Regardless of the type of fireplace you have, avoid leaving firewood in your home for more than a day or two as firewood tends to release large amounts of moisture.)

Use a dehumidifier if your home has been constructed recently or you've recently remodeled. Construction projects alter the air flow in your home, which can cause condensation on interior windows. Be sure you use the dehumidifier regularly for at least the first year after a construction project is completed.