Sometimes, you’ll notice that your ENERGY STAR® windows seem to “sweat” during the summer months. This doesn’t mean your windows are defective – rather, it’s just condensation, and it tends to happen to windows during any season throughout the year.
Condensation and Windows
Condensation is a natural phenomenon that occurs when one side of a surface is cooler than the dew point temperature of the air on the other side. During winter, this will be a common sight on your windows when the warm interior temperatures come into contact with cool exterior temperatures.
However, condensation can also happen during the summer when outdoor air is very humid and inside temperatures are cool due to your air conditioning system. Unlike when it forms on old and uninsulated windows, this usually indicates you have good quality and energy-efficient windows installed because the low-emissivity (Low-E) coating is effectively keeping the outdoor heat from getting into your home. This means your indoor temperatures stay cool and comfortable for longer, and your air conditioner won’t need to consume as much energy!
Larger View and Improved Energy Efficiency
It’s normal for condensation to disappear as outside air temperatures rise. Usually, you’ll notice condensation forming when you use your AC during the early morning hours when the air tends to be much cooler. But as the day progresses, and the outdoor temperatures climb, the condensation will dry up on the exterior of the glass on its own. It may also form during the early evening hours due to the temperature drops.