What’s Causing Condensation Between Window Panes?

LESLIE: Ruth in Michigan has got a window question. What can we do for you?

RUTH: My windows fogged up and they had condensation on them, on the centers of them, as well as when it was really cold two years ago I actually had frost on the inside of the window. And I didn’t know what’s wrong with the windows. What do we need to do with them? They were put in new about 25 years ago.

LESLIE: OK. So that could be the problem: the age factor. So now, when you say you see frost and condensation, is that on the interior side? Or are you sort of seeing it in between the two panes of glass?

RUTH: On the interior.

LESLIE: OK. So, generally, what’s happening is that the thermal seal – the gas that’s in between those two panes of glass that regulates that temperature difference –  that gas that was in between those two panes isn’t there anymore. So you’re not getting that thermal space in there to block that heat or the coolness transfer. And that can happen because there is a seal within the windows that eventually will fail. It’s not guaranteed to fail but a window that’s 25 years old, it’s a good chance that that’s no longer functioning for you.

And I think at this point, that’s not something that’s really worth repairing or you should look into a replacement window for that, which could be super affordable. You can find some great prices out there. And then you’ll be able to get one that’s truly thermal-pane and help you with all of your cool-transferring situations.

RUTH: OK. So I may have to replace my windows is what you’re saying, rather than try to repair them.

TOM: Well, that’s right. Once the window seal fails, it’s not repairable. Now, generally, it doesn’t result in a huge energy loss. It’s mostly inconvenient because, as you’ve learned, they’ll condense and fog. But if you want it to go away, you have to replace the windows. It’s not repairable.

RUTH: OK. But you’re saying it doesn’t necessarily reduce the insulation factor, huh?

TOM: It does, to a certain extent. It’s certainly not as efficient as a new window. But you are going to get a return on investment by replacing that window that’s going to equal the amount of energy you saved.

RUTH: OK. That’s what – I was wondering about that, too. OK. That’s been very helpful. I wasn’t sure what was wrong and I was wondering whether replacements would be the best option or not.

TOM: Well, now you know. Thanks so much for calling us at 888-MONEY-PIT.