How to Control Window Condensation in Winter
LESLIE: Amy in Michigan is on the line with a condensation question. How can we help you?
AMY: I live in a house; it’s about 15 years old. And every winter, I have the same problem. I’ve been here for three years but I have condensation on the inside of my windows. I think they’re pretty decent windows. I know when we had the home inspection, the guy said these are really good windows. Just wondering what I can do to control it.
LESLIE: Now, when you’re talking about this, this is in your living room, you’re saying?
AMY: It’s actually in just about every room of the house. It’s worse in my bedrooms and it’s gotten – it seems like it’s getting worse in other areas of the house.
TOM: Well, the reason that your windows condense, Adrienne, is because they’re not insulated properly. I’m going to presume that they’re thermal-pane windows, is that correct?
AMY: They are.
TOM: They’re thermal-pane windows but they’re not very good thermal panes, because the windows are super-cold. So what happens is when the warm, moist air inside your house strikes them, it condenses.
So what can you do at this point in time short of replacing the windows? You could take some steps to try to reduce the volume of moisture that’s inside the house.
TOM: This might include taking a look to make sure that your outside drainage is done properly so that you’re not collecting water.
Do you have a basement?
AMY: We do.
TOM: OK. So you want to make sure that you have gutters on the house, downspouts that are clean, downspouts that are extended away, soil that’s sloping away from the walls. That sort of thing reduces soil moisture. Dehumidification of the basement can help. You can either do it with a portable or a whole-house dehumidifier.
LESLIE: Depending on your heating system.
TOM: Making sure that your bath fans are exhausted outside, making sure that your kitchen range hood is exhausted outside. Those are the sorts of things that will reduce the volume of humidity in the house.
But I think until you get better-quality windows in there that are better-insulated, you’re still going to continue to have this to some degree, because it’s just sort of the nature of the beast. If it’s really cold outside and it’s really warm and moist inside, that condensation is going to form, the same way it happens in the summer when you go outside with a glass of ice water and you get droplets on the outside.
TOM: It’s just the nature of the condensation.
AMY: Why does it seem worse when I have the blinds drawn or the blinds are down and closed? And then there’s more condensation on the windows.
TOM: Because the windows are probably colder when the blinds are down. The warm air inside the house is not getting to the glass as readily. So the windows are probably a little colder when the blind’s down; you have less air circulation across it, so you’re not drying off some of that moisture, probably, as quickly as you would have.
AMY: Oh, OK. Yeah, that makes sense.
TOM: So do what you can to reduce the amount of humidity inside the house and then keep an eye on them. But I think, eventually, you’re going to want to think about replacing your windows and you can do that in stages. Start in the north side first, because that’s going to be the coldest side of the house and the side that will give you the best return on investment.
LESLIE: You are tuned to The Money Pit Home Improvement Radio Show on air and online at MoneyPit.com. Now you can call in your home repair or your home improvement question 24 hours a day, 7 days a week at 1-888-MONEY-PIT.