Understanding window condensation

Condensation, which can appear as a light coating of water, water droplets, frost, ice, or some combination of the four, forms on a window surface when the temperature ( °F) of that surface is less than its dew point temperature. When the humidity outside or in a certain room is extremely high, it will form moisture on windows.

Installing windows that are made with the best components will keep your windows from having as little condensation and as efficient as possible. Replacement windows with low-e and argon/krypton glass achieve some of the best thermal performance numbers in the industry. This superior performance is still only one component that works to minimize condensation. We also provide multiple-glazed glass, warm edge spacers and vinyl frames.

All homes will, on occasion, have temporary condensation which is a result of one of these occurrences:

1 New construction or remodeling – Building materials contain a great deal of moisture. As soon as heat is turned on, this moisture will flow into the air and settle on windows. This will disappear following the heating season.
2 During humid summers, houses absorb moisture, this will be apparent during the first few weeks of heating. Then the house should dry out.
3 Sharp and sudden drops in temperature, especially during the heating season, will create temporary condensation problems.

Homeowners may need to decrease the humidity level in the home in order to eliminate the formation of condensation. During the winter months, keeping a 25 °F to 35 °F relative humidity will help. Ventilation is also a very effective way of removing excess moisture from the air.

You must remember that windows do not cause condensation, and therefore, windows cannot cure condensation. However, insulated windows should help relieve the situation.

To increase the resistance of windows to the formation of condensation, it is important to maintain the surface temperature of the window above the dew point. To accomplish this, manufacturers must reduce the amount of heat that transfers through a window, which is called the thermal transmittance or U-factor of the overall window product. The higher the U-factor of a window, the higher the potential that condensation will form on a surface of the window unit.