Exterior Window Condensation is no Cause For Alarm - July 4th 2011
In dealing with your home as a system, I recommended installing energy efficient windows as one way to upgrade your homes energy efficiency. Homeowners who have energy efficient windows may notice moisture forming on the outside under certain weather conditions. There is no need to be alarmed if you are in this group!
The moisture on the outside of the window is condensation. This usually happens during periods of warm weather and high humidity near the time of sunrise. It will soon evaporate when outside temperature rises. As we know, condensation happens on cold surfaces. During the night, if the outside temperature drops below the dew point then condensation forms.
The fact that the condensation is forming on the outside of your windows means that the windows are in fact, doing what they are supposed to do.
It's Just That Easy!!