Winter Window Condensation Problems

If you live in a cold part of the country, you’re familiar with condensation and icing on the inside of windows. This problem is becoming more prevalent with new home construction due in part to the increased insulation and “tightness” of homes. As temperatures continue to drop, I get a lot of inquiries about window condensation.

Condensation and ice form on windows because the window surface is below the dew point of the air near the window, so some of the moisture in the air condenses on the glass. The higher the relative humidity of the air near the window, the higher the dew point temperature. There are basically two ways to prevent this from happening. The first is to reduce the relative humidity in the house, and the second is to increase the temperature of the window glass.

Reducing relative humidity is the most effective way to reduce window condensation. Make sure exhaust fans are properly ventilated and in good working order. Bathrooms, dryer vents, and kitchen vents are the main culprits for bringing higher humidity into the house. Proper ventilation is crucial because today’s homes have been so well insulated that there is no way for extra moisture to escape. To be effective, the relative humidity must be reduced to a minimum of 40%.

Raising the window temperature is a bit more challenging. For starters, make sure your window shades and shades are open during the day to let in the sun and also allow air movement to help dry things out. By opening curtains and blinds, you also allow the warmer air in the room to warm the window.

If you follow these steps and have good quality windows, the condensation and ice should go away. For additional information, contact your window manufacturer or check with your local building supply company.