Ice on inside of windows

Old 01-27-05, 08:55 AM
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Ice on inside of windows

I've replaced some of my old single paned windows (with storms) with Pella insulated low-e/argon windows - alum clad outside, painted wood inside. During this recent VERY cold spell (single digits every morning) my sons room windows get some ice forming inside at the bottoms of each sash.

We keep the door closed at night and have baseboard heat (therefore no air exchange) so my theory is he's just breathing too much Our bedroom is bigger, and it has 2 old windows, and 1 new one, and there's no ice.

Is this normal under the circumstances? Are the windows defective in any way? Will this damage the windows? We clean it up every morning.

Any preventive measures? Humidity cant be that high with it being cold, so I'm not going to run a dehumidifier - my son wouldnt be able to breathe!

Thanks for any tips...

Old 01-27-05, 09:36 AM
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Yes, it is normal. Sad to say it, but often, old windows that had the storm window 4" away from the interior glass are often better at keeping the inside glass above 32F. Overall, your Pella windows are more efficient, but this is a common complaint among people who live in cold climates.

Since you have baseboard heat, with no air movement... and you keep the door closed at night, maybe the best solution would be a quiet fan that could circulate the air in the room. Just having some air blowing on the window would help immensely.

The moisture will do damage to the wood finish eventually, so it is best to try to keep it dry any way you can.
Old 01-31-05, 06:45 PM
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excess humidity?

XSleeper is right on the money with his reply.

Unfortunately, the newer windows really are (or should be) so much tighter than the older ones that they may be preventing the air exchange that your old windows allowed. Lacking the air exchange with the drier exterior air allows the warmer air in your home to rise to a much higher relative humidity level than a house with older windows might have achieved.

The explanation of what is happening with your windows can become quite long and complex, but in a nutshell the surface temperature of the glass is below the dew point of the air in your son's bedroom. That allows water to condense on your son's window. The fact that you have ice forming MAY indicate a slight air leak, but that is just a guess.

Anyway, XSleeper's idea of a small fan blowing air on the window is a very good one. Any air movement should help somewhat.

Good luck

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