VELUX Offers Tips for Condensation and Skylights

Condensation is usually more noticeable on skylights because warm, moist air rises to the ceiling. The problem, however, usually isn’t the skylight. It’s the excess moisture in the room. Here are a few tips if you notice condensation on your windows or skylights:

1. Check the humidity level setting on the furnace or humidifier. The colder it gets outside, the lower the humidity setting should be. (see below)
2. If possible, turn on a ceiling fan near the skylight to move the air. This will keep the warm air in the room, and off the glass.
3. Run the exhaust fan in the bathroom and kitchen to move some of the warm, moist air.

Recommended humidity settings based on engineering studies at 70°F indoor air temperature.

Outside Air Temp           Inside Humidity
-20°F or below                      15-20%
-20°F-10°F                            20-25%
-10°F-0°F                              25-30%
0°F-10°F                                30-35%
10°F-20°F                              35-40%

Eliminating excess moisture by providing adequate ventilation and air circulation will go a long way in preventing condensation.