My air return system is in a small closet in my garage. When I run the A/C when it's hot and humid out, the ducts sweat and drip a lot of water onto the wood platform that the HVAC and water heater sit on. The homeowner before hand must have not cared and never did anything about it.
I on the other hand don't like seeing all the water laying around, and I don't want it to eventually rot the wood to death.
What is the best way to insulate sheet air ducts?
Here are some pictures of my fiasco too.
Best Answer
(links are to Google image search)
With foil and fiberglass duct wrap you have to use tape, and be able to get all the way around or it won't stay there (the tape has to lap over its other end or it will not hold).
I'd recommend self-adhesive foil and foam duct wrap.
You might want to do the easy-to-reach and the majority of it with fiberglass, and use the self adhesive where you have to, to keep the cost down.
Surface prep is to wipe with alcohol - do not use mineral spirits. And of course; to be dry.