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Condensation on bedroom windows

We live in a 50 year old house and the two windows in the bedroom get condensation on the glass inside the room overnight. It is too the point where you can take a paper towel and it is soaking wet from just one payne of glass. They are not old windows either. We even took the moulding off the side of the window too see if there was some issue with no insulation, however the sheet rock goes up to the side of the window itself. We have even looked at the raidiator in the room to see if there was a pine hole leak and have found nothing on that end either. We just recently put an additional 9 inches of insulation in the attic since we only had three inches up there, however still no change on these two windows. We are at a loss as to what is causing this. It is also causeing mold to grow on the window at the part where the glass touches the white part of the window. Please help.

Re: Condensation on bedroom windows

Stop breathing when you sleep?

Maybe a dehumidifier?

I would guess you have a dew point issue.

Re: Condensation on bedroom windows

So how would you fix it other than a dehumidifier?

Re: Condensation on bedroom windows

If you don't have one .... get a hygrometer to measure the humidity inside your home.
I'll take a guess the humidity level inside your home is around 60 - 70 %.

The higher the humidity level inside and the lower outside temperature = condensation on the windows.

You 'll have to reduce the level down to a least 50% or lower.

Re: Condensation on bedroom windows

When you say these are not old windows, are you indicating that they are newer double-glazed/thermal-pane windows?

If older single pane windows....is there also a storm in place?

Your locale is?

What temperature do you keep this room at?

Do you turn the heat down at night?

North or east wall, perhaps?

It's almost assuredly a relative humidity issue as already mentioned.

Aquarium in the room...or similar?

Adjoined bathroom without an exhaust vent, maybe?

Just the installation of a ceiling fan to move the air around the room and over these windows may do the trick.....particulary if the RH is kept down to a reasonable/lower level.

If your RH is already around 20 - 30%...for an experiment, try positioning a fan within a few feet so it blows over/toward one of these windows and leave it run overnight. Even on low setting should move enough air. The idea here is to move warmer air over the glass to increase its temperature and therefore raise the dew point.

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