Stop Windows from Sweating in Winter
LESLIE: Something’s going on in Louisiana with Phillip’s windows. How can we help you?
PHILLIP: Well, here a couple of months ago they were continually sweating on the inside when it was cold outside with, you know, heat running on the inside.
TOM: Yeah, mm-hmm.
PHILLIP: It’s a big (INAUDIBLE) home. It’s only six – well, it was built last June.
PHILLIP: And I was trying to figure out how to solve the problem. In the meanwhile, I believe I alleviated the problem but I’m not sure if it makes sense what I done; if that corrected the problem.
TOM: What did you do, Phillip?
PHILLIP: I actually found out that I had the wrong air filter on my central air unit on the inside. And I had a feeling that it was running around my filter and I don’t know if that was creating something there where the, you know, the system wasn’t able to dry up the air quick enough and it was drawing the moisture out of the air in the home or if that even makes plausible sense.
LESLIE: Well, it could also be that the exterior temperature and the interior temperature are much more similar at this time of year. It could just be that the weather has sort of corrected it as well.
PHILLIP: Yeah, if you have a lot of – a lot of humidity in the home in the winter time and then you have cold windows that are not properly insulated, it sounds to me also like the windows may not be insulated very well; even though they’re newer windows. If the windows are thermal pane and have an insulating glass seal between the panes, you shouldn’t be getting that level of condensation because the inside glass shouldn’t be cold enough to let the moisture that’s in the air condense and form those water droplets. So, I’m a little bit concerned about the quality of the windows in this fairly new house in allowing that to happen.
The other things to look at are the moisture sources inside the house. For example, cooking – do you have a fan that vents outside or is it a recirculator; bathrooms – again, do you have fans – bath vent fans that vent outside?
LESLIE: And not just into the attic. And are you running them, after you take a shower, for 10, 15 minutes?
TOM: Yeah, and you also mentioned that you have central air conditioning. I don’t think the filter had anything to do with this. That would only cause dirty air. But central air conditioners are actually not very good dehumidifiers. They’re fairly inefficient dehumidifiers. There’s another type of unit that you could add onto that that’s, in fact, called a whole home dehumidifier, that is designed specifically to take out moisture and humidity in the air. In fact, Aprilaire makes one that takes out like 90 pints of water a day out of the air. And so, that’s an option for you as well.
Are they thermal pane windows?
PHILLIP: Yes, they were – yeah, they’re supposed to be. And I didn’t actually build the home myself but …
PHILLIP: … according to the builder. And he did send me paperwork over showing they are supposedly thermal pane windows.
TOM: I might want to push that issue a little bit further, Phillip, because you shouldn’t – with newer windows that are properly made – get that kind of condensation. You might want to ask for the Fenestration …
LESLIE: The label.
TOM: Yeah, the Fenestration Rating Council label on that because that will tell you – the National Fenestration Rating Council, the NFRC label, will tell you how energy efficient that window is and also find out if there’s a manufacturer that you could speak with because I’m just wondering if they’re not insulating the way they’re supposed to be. You should not be getting that level of condensation in a window that’s only a year or so old. OK, Phillip?
TOM: Thanks so much for calling us at 888-MONEY-PIT.