Morning Wet Glass: Three Checks Before You Blame the Windows

Hollis Varrow
· 2 min read

Wet glass on a cold morning is usually a moisture problem inside the home, not a window failure. Before pricing replacements, run three quick checks. The full walkthrough is in the ten-minute triage guide: https://dry-glass-notes.surge.sh/articles/ten-minute-wet-window-triage.html

First, measure. Put an inexpensive hygrometer in the room with the wettest glass and read it in the evening and again at first light. If indoor relative humidity sits above roughly 50 percent while it is cold outside, glass will reach its dew point overnight regardless of how new the windows are.

Second, check exhaust fan timing. Bathroom and kitchen fans often run only while the light is on, which stops them before the moisture is gone. Leave the bathroom fan running for 20 to 30 minutes after a shower, and use the range hood whenever pots are boiling.

Third, look at laundry. A single load dried on a rack indoors can release several litres of water into the air. If wet windows line up with laundry days, dry clothes in a vented dryer or in a room with an open window and the door closed. More detail: https://dry-glass-notes.surge.sh/articles/laundry-drying-indoors-window-condensation.html

If all three checks come back clean and condensation persists, then it is time to look at the windows themselves. More practical notes are at https://dry-glass-notes.surge.sh/