Fogging windows upstairs?

[backpack09]

When I burn in my stove rather than heat with my forced hot air system, the windows in my 2nd floor bedroom always seem to fog up long before we head to bed. These are relatively modern double pains, 4 double hung, and a 5x5 bay. I have tried running a dehumidifier and ceiling fan, but still get the same results.

Does anyone have an opinion on what is wrong?

The house is a 50 year old modified cape, with a modern/ well insulated second floor with a large dormer on one half.

 

[Jags]

Hmmm....fogged up windows = warm, humid air against cold window pane. Have you tried to run the force air furnace fan for a few minutes (lots of "f"s in that question)? It may just be the ticket to get everything "stirred" up again.

 

[burntime]

The level of humidity changes. You heated the downstairs air and the upstairs cooled and holds less humidity, it condensed on the glass. When the house dries out a little it should subside.

 

[Diabel]

It only happens in my house shortly after we head to bed

 

[pinewoodburner]

It only happens in my house shortly after we head to bed

That is what I was thinking. It could be that your windows are not that well insulated. My florida room sliding doors do the same thing and are double pane windows, but the replacement windows in the house with the low e do not. You may need a storm window on the upper level. The condensation inside can cause damage if you have wood trim.

 

[Diabel]

BP I would not worry too much about it. This time of year there is a lot of humidity in your house. And likely it cooled fairly quickly outside... I get that too around this time of year (well insulated house, no running of the furnace, very wet & cool outside, still humid in the house).

 

[Highbeam]

What is the measured RH in that room with the foggy windows?