Insulate Air Ducts to Reduce Condensation

Learn how to reduce condensation in your air conditioning ducts and vents. Find out how insulating the area around your rood vents and air ducts will reduce humidity and prevent condensation.

LESLIE: Now we’re going to talk to Clyde in Florida who is trying to deal with moisture in a bathroom. And Clyde, you are already in a super-humid state. How can we help you?

CLYDE: Yes, it is that. I purchased a mobile home at the beginning of the year …

TOM: OK.

CLYDE: … and it has cathedral ceilings in it and the vents are in the ceiling. And I’ve noticed in the hotter days that the vent in the front bathroom, it builds up condensation on it and then it drips and makes a puddle on the floor and I’m just trying to figure out if there’s anything I can do to eliminate that.

TOM: This vent, is this the air conditioning vent?

CLYDE: Yes.

TOM: Hmm. Well, the condensation, is it collecting around the outside of the duct and then dripping through the ceiling?

CLYDE: Well, it’s just dripping from the duct itself. From the vent.

TOM: (overlapping voices) From the duct itself.

CLYDE: Correct.

TOM: Probably what’s happening is this. There’s so much humidity in the space above it that it’s condensing on the outside of the ducts, running down and then dripping into the room and the solution, therefore, is to do a couple of things. First of all, take every step you can to reduce the level of humidity in the attic. That would be by making sure that you have good ridge ventilation and soffit ventilation so you’re flushing air out of that.

LESLIE: Mm-hmm, and also make sure that your bathroom ventilation vents themselves are venting outside and not just into the attic space.

TOM: Yeah, because that could be dumping moisture in there. And then, also, make sure that you insulated around that duct; especially in the area close to the bathroom. If you insulate the duct from the outside surface then you can’t get condensation in it because you’ll be protecting that from the temperature exchange and it forces the moisture out of the air, resulting in the water droplets and that is what results in the moisture kind of running down into the floor.

LESLIE: You are tuned in to Money Pit and maybe you are still feeling a little full from your big Thanksgiving meal. Well we’ve got home improvement projects to help you work off those extra pounds in your house and on you, so give us a call now at 1-888-MONEY-PIT.