View Full Version : window condensation

Lanny Freng
03-07-2008, 02:38 PM
outside air temperature is around 10 degrees. Inside was about 70 degrees with the humidifier set at 30-35% humidity. There was alot of frost and condensation on the interior of the windows. The windows were Vetter casement-double pane windows... I thought maybe a malfunctioning humidifier was possibly increasing the humidity above what the controls stated. Maybe the windows are just failing due to age. They are about 15 yrs old which seem kind of young to fail but I dont think Vetter makes the highest quality window. There was no condensation between the two panes of glass so I would think the seal has not failed. The bath vents were all vented to the outside, not sure if they used them or not though.... Here are some pics of what they looked like.

Scott Patterson
03-07-2008, 02:58 PM
Well heck it's cold as a well diggers ass outside and warm and toasty on the inside. If you are going to have a conflict of the air masses it will be at those windows. Casement windows have tendency to have leaky rubber gaskets that seal the frame and the mechanical operation. I would bet this is why the condensation is forming like it is. But, it is almost impossible to determine.

Lanny Freng
03-07-2008, 03:10 PM
thanks for the info, gonna go with- test the humidity levels of the home, if they are ok your windows are just leaking excessive cold air and there really isnt a easy fix.

Raymond Wand
03-07-2008, 03:22 PM
I concur with Scott's opinion, and it looks like the gaskets may be missing. Didn't see a bottom gasket imprint on the frosted portion.

There is a caulking compound called Draft Stop. The clear caulking is applied along the operable portion of windows to seal it very effectively. It sets within an hour and can be removed very easily just by pulling it away. Safe on paint, and wood. Very effective, beats having to stretch plastic film over the window and shrinking it with a hair dryer. Stops drafts, great for older inferior windows.


Gunnar Alquist
03-07-2008, 07:44 PM

Actually, a lot of moisture is introduced to the interior air by exhaling. When I see a lot of condensation on windows, I recommend everyone hold their breath. :cool:

Patrick Norton
03-07-2008, 09:19 PM
Are there blinds on the windows? I will see excess condensation and frost on many double pane windows on cold days when people keep the blinds closed most of the time. If the warm air from the house is not allowed to keep the windows warmer you will see excess condensation or frost.

David Banks
03-08-2008, 07:12 AM
I think Scott nailed it. I have pretty good replacement windows but in real cold weather I will get some window condensation and frost.
Might want to make sure there is no issue with furnace/water heater flue problems.

Steven Turetsky
03-26-2008, 01:48 AM
I also agree with Patrick, as far as covering the windows and preventing the air to circulate.

Is anyone boiling water to help warm the house?

Are there venting/improper combustion issues with any heating systems, etc?

I recently inspected a 4 family that had three "dry" apts and 1 with major condensation/mold issues. The windows were covered and the tenant was boiling water all night. There were also insulation/draft deficiencies.