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Bathroom Vent

I have just purchased a house with a bathroom vent that exhausts into the attic. I would like to put in a gable end discharge. The roof is very steep and two stores up so that is not really an option. My question is, are there length limitations for ducting from the fan to the gable? I have read lots of posts on here and every one says you can duct to the gable with in reason, but how much is reason? Thanks.

Re: Bathroom Vent

Since my last post I have done a little research, I noticed that when looking at fans in the stores the fans have ratings for how much air they can move. I assume I should get the fan that can move the most air since I will be venting out of the house about 15 feet away. Also, should the vent pipe be sloped a little so condensation does not sit in pipe? Any help with this length of venting problem, would be appreciated. Thanks.

Re: Bathroom Vent

Generally it's recommended that 1 CFM of exhaust for every square foot of bathroom. Also if the bathroom has a toilet and a tub/shower 50 CFM is recommended for each fixture. So basically an exhaust fan rated at a minimum of 100 CFM should be used in a regular bathroom.

Ensure the exhaust fan has at least 4 inch provision for ducting , the larger the better for longer runs.

I highly recommend using metal ducting and seal the joints with foil duct tape also cover with dust insulation... don't use the cheap white plastic flex duct.

Try and avoid hard 90 degree transitions .... make them as gradual as possible.

You're correct with sloping the duct ..... have it slope toward the gable vent.

Hope this helps. :)

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