I had all my old aluminum windows replaced with vinyl Low-E, gas filled type.
Here in Michigan we've had some pretty cold nights the last few days. I noticed water droplets in the bottom corners of the unmovable panes but "not" the sliders.
My humidity was 45-47%. I have a dual input therometer with K-type bead probes which I taped to a corner on the pane. I also have a logging hydrometer which calculates dewpoint, both can download to a PC.
When the night time temperatures drops below 20F, the surface temperature of the glass in the corners goes below the dewpoint! Bingo!!
All I can read about Low-E glass surface temperature states that it should be 40-50F higher than the outside temperature. Mine are about 20F higher in the corners but the center of the pane is 13F warmer. This means that the cold temperature is being transfered through the vinyl frame. Not sure about all this sales talk or are not all Low-E vinyl windows the same.
The information I read from the glass manufactures sites but what happens when they are installed in a frame, etc?
All tempertures taken were compared with a thermal imager and agreed.
I dropped my humidity to 40% but that didn't help. I drop it to 35% now but last night it didn't get that cold.
I've search here and found threads that said that it's not the windows but if they aren't doing what their supposed to, well?