Sealing air leaks in your home's HVAC ducts is something that should be done by a professional, using the correct type of duct sealing tape or mastic. Learn which options work.
LESLIE: Sherry in Arkansas has a question about cleaning air ducts. What can we do for you?
SHERRY: Yes, ma’am. We have an older mobile home and I was wondering about how we would go about cleaning the air ducts  because we’ve possibly gotten some leaks in them that possibly need to be repaired.
TOM: When you say leaks, do you mean air leaks?
SHERRY: Yes, and it’s an older mobile home that’s got – it’s got central heat and air and some of the ductwork in the floor is – I guess it’s got some leaks in it because we can feel the cool air underneath the mobile home.
TOM: Alright. Well, that would be the weather-stripping between the ducts and where it attaches to the house. So, the first thing to do is you’ll need to have a duct-cleaning company – because there’s special gear involved here, Sherry. There are special vacuums and brushes that get inside the ducts and scrub them out. But the other thing that has to be done here is you may have to do some repair to that, so you might have to have an HVAC contractor go inside or underneath the mobile home and try to find the place where the gaps are.
Now, I will warn you that most of the time contractors will seal ducts with duct tape but that’s not the right product to use.
LESLIE: Mm-hmm. It dries out.
TOM: It dries out and falls out and that’s why you get these gaps. You want something called UL-181 tape which is not going to dry out based on the heat. It’s a silver, foil-faced tape that’s much more permanent than the standard duct tape.
SHERRY: Oh, OK. Thank you.