Fogging issue between storm & double hung
We recently had glass storm panels (1 pane covers entire opening) installed on our 75 yr old home. Windows are original wood double hung, single pane in good condition. The problem of fogging between the storm panels & windows only occurs in an upstairs bedroom (3 windows) & one opening situated at the top of the stairs adjacent to this bedroom in the hallway. This only occurs sporadically & most recently it was in the morning, A/C had been on overnight, inside temp was around 70 degrees, & outside temp was slightly cooler. No rain, so assume it isn’t outside moisture getting in from exterior side of the storms. I would assume with the A/C on & outside humidity at a low level that this isn’t the problem. It also puzzles me why no other windows are doing this if it was related to the ambient humidity in the house. We’re currently having several rooms repainted, but would paint (interior latex) raise the humidity level that much? And why would it only affect this specific area & not any others being painted? Any thoughts appreciated.
Replies
Which side of which pane is fogging? Presumably it's condensation collecting on the outside of the inside pane, caused by moist air trapped between the two panes and being cooled below the dew point by the AC.
Why it's happening only to this one window is hard to say with any certainty -- there are several possibilities:
1) This window doesn't get any sun, and so moisture trapped between the panes is not driven off.
2) The window is kept cooler than others, due to the placement of AC registers.
3) The inside window actually seals too well (compared to others), so that dry air from inside does not get into the space.
4) The storm doesn't seal well enough, allowing too much moist outside air to get in.
5) Prevailing winds, et al, cause a vacuum in the space between panes of that window and results in moist outside air being drawn in.
6) Many others.
Just to clarify- it's 3 windows in the same bedroom & one window in hallway outside this bedroom. Thanks for the response- it gives me several paths to eliminate as probable culprits. I'm waiting for it to happen again to see on which glass the condensation is collecting. But to address your list:
1. This side of the house doesn't get morning sun
2. Multiple windows in same room rules out register problem I would imagine
3. Possibly, but they're all pretty old wood double hung & I feel like none of them seal that well
4. There are weep holes in bottom of storm & these were installed to be removed for cleaning (single pane storm window- no operating or screens) so they aren't incredibly air tight.
5. I guess this would fall under same conditions as #4. Possibly first test would be to caulk storms & seal better thereby eliminating outside moisture getting in?
Thanks for your help.
10-4 thanks