Protecting bathroom fan from attic cellulose insulation

An exhaust fan has been added to the upper floor bathroom. The attic's insulation (cold climate!) is blown cellulose particles. Is it customary to cover the fan's top housing with some kind of a cap to protect it from being contaminated with the insulation dust?

Reply to
Alfred K.
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Hi, The exhausted air should go outside thru insulated duct. How come are you worried about dust?

Reply to
Tony Hwang

On Thu 01 Oct 2009 09:36:50p, Alfred K. told us...

You should *not* be exhausting bathroom air directly into the attic. There should be a duct (preferably insulated) connected to the exhaust fan and connected to an appropriate exterior vent through the roof, eave, or sidewall of the house. This would also apply to exhaust fans anywhere in the house; e.g., utility room, kitchen, etc.

Reply to
Wayne Boatwright

Vent moist air into an attic and it will be black with mold fairly quickly. Then follows rot, vent it as they all are supposed to be done, outside.

Reply to
ransley

*No it is not customary, but not a bad idea.
Reply to
John Grabowski

An insulated duct, of course, is there, connected to an ridge vent on the roof. I am asking about some possibility of contamination even with the duct present.

Reply to
Alfred K.

NO

Reply to
hrhofmann

No, you won't get contamination. However, I find it actually contrary to the building code in regards to vapor barrier sealing, that most manufacturers, even high priced ones, have many holes, opening, gaps and other areas that water vapor and drafts can easily get through. When I install such fans, I always cover every hole, opening and joint with metalic duct tape on the inside and outside of the housing. This gets as close as possible to a good vapor barrier and prevents the fan's vacuum from pulling insulation dust into the housing and drafts from entering when the fan is off.

Reply to
EXT

On Fri 02 Oct 2009 11:10:46a, Alfred K. told us...

If the duct is sealed to the exhaust fan outlet, I can't imagine how dust would enter the system from the attic. You could, of course, seal all perceptible joints, corners, screw holes, etc., on the housing with duct tape.

We had a similar installation in a previous house with similar insulation. Nothing additional was required and we had no problem.

Reply to
Wayne Boatwright

Was it in the area with very hot summers? I am thinking of potential overheating if the fan housing is sitting deep in the cellulose without any air gap surrounding it.

Reply to
Alfred K.

The motor is cooled by the airflow

Reply to
BQ340

On Fri 02 Oct 2009 07:05:45p, Alfred K. told us...

Yes, very hot but not humid. No problems at all. A lot depends on the quality of equipment you buy.

Reply to
Wayne Boatwright

how high is the metal tape rated for? Some are only 200 degrees - is that a concern?

Reply to
dv

If your attic is over 200F, you have more problems than tape rating.

Reply to
trader_4

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