Duct Liner

[PM101]

I have a project in which one of our AHU’s is very close to an outside air plenum. I do not have space available to install insulation on the outside of the plenum and have opted to line the plenum instead. I am concerned about water infiltration into the plenum and would like to find a liner that is water proof so that I do not have to build a double wall plenum. Has anyone ever seen or used a waterproof duct liner? Any help would be appreciated.

 

[KiwiMace]

Why don't you just make the plenum smaller - in effect this is what you have done by lining it.

 

[xac33ncsu]

http://www.insulation.org/mtl/pdfs/012230_487.pdf

I've seen this stuff used before, be aware I hear its pretty expensive.

 

[KiwiMace]

I have used Mylar in the past, sandwich under perf.