Window Fogged (What’s It?)

It’s not privacy glass even though it works as one. Insulated glass that is standard in all modern windows is made up of two panels of glass separated by a filler piece.

The seal between the filler and the glass develops a small hole allowing air into the space between the glass panes. The moist air begins a slight shading the glass, followed by visible moisture. The moisture slowly morphs into a whitish film on the glass which blocks visibility. It cannot be wiped off because it’s between the glass.

The glass can be removed from the sash and a replacement installed. It’s a failed window glass seal.