Fixing Duct leaks

[pinkchry]

Contractor broke down the drywall in the process of remodeling the bathroom and I discovered that the ducts behind the HVAC have huge gaps in them. In the brief time I had I put a lot of foil tape and got most of the leaks covered. Could not feel any air coming out there.

https://imgur.com/a/yfqchNL

How good is the foil tape? I guess at some point I could get someone to do a proper fix. I'm sure there are similar gaps elsewhere - need to find them using a thermal camera.

Thanks!

 

[danski0224]

Mastic tape is better than foil tape.

Actually sealing the connections with brush-on duct sealer is better than either.

All connections will leak- duct to duct and the takeoffs. Leakage rates of 20-30% for unsealed metal ductwork is not uncommon.

Due to access issues, a product like Aeroseal might be the only viable solution.

 

[Jeepster04]

Thats a pretty critical leak there. Is that the air handler were looking at? It doesnt look like typical duct work.

Ive been blown away at the leaks Ive found in my house. Cant figure out how the unit was able to heat and cool the house before I fixed it. Return duct was uninsulated in the attic AND had a 6"x16" hole where they didnt block it off between the ceiling joints(used the space between joints as the return duct). Couldnt figure out why the filters were so dirty after only 2-3 months. Now there fairly clean when I change them.

Also found a 8"x8" hole in the supply duct under the floor where the duct work reduced down to a smaller size.. Wild.. Before I couldnt hear the air coming out of the vents but now it has a nice roar to it.

 

[CKS1955]

I used a combination of either foil tape or brush on sealer. Foil tape for straight seams and brush on sealer for elbows, etc. it’s been 15 years and both are performing well. We sealed every seam on in the entire supply side and return side during the construction phase.

Jay

 

[pinkchry]

Thats a pretty critical leak there. Is that the air handler were looking at? It doesnt look like typical duct work.

Ive been blown away at the leaks Ive found in my house. Cant figure out how the unit was able to heat and cool the house before I fixed it. Return duct was uninsulated in the attic AND had a 6"x16" hole where they didnt block it off between the ceiling joints(used the space between joints as the return duct). Couldnt figure out why the filters were so dirty after only 2-3 months. Now there fairly clean when I change them.

Also found a 8"x8" hole in the supply duct under the floor where the duct work reduced down to a smaller size.. Wild.. Before I couldnt hear the air coming out of the vents but now it has a nice roar to it.

I think this is the air handler. I'm thinking of cutting the drywall and putting an access there to check for leaks again.

As far as the hole into the attic, I have a similar 2' x 2' hole where the ducts stick out into the attic. I'm nervous about sealing it as there may be CO issues - a couple of HVAC guys I had did not inspire much confidence.

https://imgur.com/a/55ZTxEI

How did you seal the hole?

Thanks!

 

[Slowgsr]

Before I finished my basement I sealed everything with duct sealer! Up here its code for commercial but not residential