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Are there any more rigid alternatives to fiberglass insulation for insulating rigid ductwork?

Aston01 | Posted in Mechanicals on

Fiberglass insulation by it’s nature needs to remain lofty to achieve it’s a R-value, but it tends to be easily compressible. I’ve never really been a fan of it and find I don’t particularly like having to deal with it when insulating rigid ductwork.

I’ve seen some alternatives used that look almost like aluminum foiled bubble wrap, but have been skeptical about their effectiveness.

Can anyone suggest a wrappable duct insulation that is less prone to compression than the fiberglass options?

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  1. Expert Member
    BILL WICHERS | | #1

    The commercial mechanical supply houses have a rigid fiberglass insulating board that is around 1" thick that is made for this purpose. This material is usually attached to rectangular duct with special nails that are spot welded to the duct by tapping them with a welder. The product has a white facer and there is white finishing tape for corners to give a clean finished appearance.

    Reflectic makes a double layer bubble type duct insulation wrap that is OK, but they only rate it to about R4 or so (which might be a bit optimistic) so it doesn't technically meet code, but it's better than nothing and is a good product for some applications. I'm actually planning on using that in a few ducts in my basement where I want a little insulation but don't need full R8, but I do need a compact material to work with due to limited space.


    1. Deleted | | #2


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