Insulation Sealer/Fungicide

[A/C-SuperCool]

Hey guys, I'm getting ready for a job where the customer wants the Supply and Return plenums sealed to keep the fiberglass insulation out of the air stream. Can't say I blame him, but what products are on the market for this? I know Foster has a line of products but which one should I use?

[snupytcb]

are you talking about encapsulating it with spray foam or just sealing the seams with mastic?

[A/C-SuperCool]

coating the inside of the plenums to keep the fiberglass insulation out of the air stream and also prevent mold growth. We seal all seams on the exterior with mastic....

[shellkamp]

wouldn't coating the inside of the duct essentially create another vapor barrier, potentially causing condensation on the inside of the ducts?

Of course; I'm thinking like a Floridian, Ducts in the attic and used primarily for cooling. I guess it would be okay if the ducts are connected to a furnace.

[energy_rater_La]

why not change plenums & insulate them externally?

I've done that for a customer with fiberglass issues.


best of luck.