Someone in our neighborhood just got new double-paned virgin vinyl windows and the results seem odd (well, at least to me). We’ve had some abnormally humid, warm weather and several of the windows are showing lots of dew on the outside. On the southern side, the picture window was almost covered with dew except for about a 2" border from the frame. On the western side, all the single-hung windows have dew on the upper window and none on the lower window. Similarly the one window on the north side has dew on the upper window, but not the lower one. My speculation is that the lower windows don’t collect dew because of the screens – although I’m not really sure why that should matter. The windows are well caulked and there’s no moisture on the inside.
The windows’ dew disappears shortly after sunrise,albeit except for the north side (which, I am told, cleared later).
Also, I’m told all the remaining older windows (aluminum frame, double-paned but with very little distance between the glasses) don’t show any dew and never have.
The owner contacted the window company and they’re coming back out, but as an objective audience how would you interpret this result? Like I said, it sure seems odd…
I’m looking at getting windows and the observations are of a neighbor’s recently installed ones. But, yes, the home was probably warmer than the outside. There was a heavy dew that morning.
“The heat transfer from the house to the outer window pane is not enough to warm it higher than the dew point.” Would this explain why his older aluminum frame windows (with a smaller gap between panes) did NOT show any dew – that the heat of the house was being conducted to the external glass?