Insulating Exhaust Fan Conduit

Jun 28, 2005 5 Replies

Any thoughts / experience with insulating material for a 4 inch diamter tubing used in a bathroom exhaust fan installation? The tubing shall be in an attic crawl space in a ranch style house located on Long Island, NY (typical low and high temperatrures: 0F and 100F degrees).



I am wondering if pipe insulation or batt fiberglass insualtion should be used in this application ?



Is Owens-Corning Fiberglass Duct Wrap

formatting link
material for this application ?


I don't know what you purpose for wrapping is, but you may be able to buy

formatting link
appropriate material for this application ?

I am concerned that condensation might develop within the attic crawl space and cause damage to other insulation material.

I have read here >I don't know what you purpose for wrapping is, but you may be able to buy

[snip bottom quote]

If you exhaust *into* the attic, insulation will just help trap the moisture you're putting up there. Exhaust *through* the attic to the

*outside*, through a wall or through the roof, i.e, run the duct to the outside. Slight leakage from duct joints won't amount to much, but if that concerns you, wrap the joints with aluminum tape. It won't hurt to wrap the duct with fiberglass wrap, but probably won't accomplish much either.

formatting link
appropriate material for this application ?

In most situations you should not have a problem with it, just be sure vent it to the outside not to the inside of the attic.

I'm in CT. I used 4 inch metal tubing and minimized the amount of flexible tubing (decreases flow rate and increases noise). I used a flapper valve type of connection on the roof. I used Panasonic fans. I wrapped the entire tubing in insulation (I used both reflective, metallic and normal pipe insulation). It took way, way longer than I thought.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required