Designing Kitchens and Bathrooms - Bath Fan

Hi all. This is my first time on this site so if I'm in the wrong department, please let me know and I'll slither away to the right one.

I've got a bathroom that gets a little moldy and some peeling paint. There is a window that opens but there's apparently just not enough air movement to dry things out after a shower. I want to install a ceiling fan and now here's my question:

Do I absolutely, positively have to vent it through the roof or can it be ducted to a soffit vent? I know it physically can be done, but my concerns are (a) could it be a code violation, and (b) couldn't the dampness end up causing moisture damage to the eaves?

I'd like to get this project done before summer gets here and the attic gets hot enough to roast meat.

Thanks.

George715,

Code requirement is that a "exhaust fan" must be vented to the exterior. How you do it is your decision. Out the roof is the best for obvious reasons as this is agood guarantee that moisture is out. Soffits on the other hand can be a problem if we are talking about wood. There is available a boot/cover that can be placed in the soffit. In any case, try and get this vented to the exterior, even just laying the duct within the soffit is a bad thing even if you have metal soffits. Any moisture coming out could get sent into the attic space and damage insualtion and wood over time.

Good Luck!

Do you have an adjacent bathroom with an exhaust vent fan in place?? If so, you can connect a new duct to the existing one using a Wye. I did it for my master bath and it took me less than a day.

Doug-

Thanks. I'll look around for the soffit boot deal if it even exists in our area (No. CA). If not, I'll need to get someone that'll punch a hole in the roof for me. I know I don't want to do it.

Thanks again.

George

Masterjoe-

Sorry. I meant to reply to you as well. Oops. The other bathroom does indeed have a vent to the roof and I'd thought about tying into it, but they're about 30 feet apart. Your thoughts?

Thanks.

George

30' is too far for moist air to travel; they recommend a horizontal run of no more than 6'. The reason for it is the danger of water condensation due to trapped air.

Soffit adapter boot can be easily purchased at any plumbing supply store; check the nearest Lowes as well.
How far is the nearest soffit from your bathroom?? It shouldn't be farther than 6', due to the same reason that I described above.

Yeah, I kind of had a hunch (as Quasimodo would say) that 30' was a bit too long. I think the closest soffit vent, although it's acutally an eave vent, is probably no more than 6' and more likely 4'. I'll get up there this weekend and get some better measurements so I know more of what I'm dealing with (if that sentence makes any sense at all).

The vents are on the vertical outside wall. Do you see any problem with moist air somehow dribbling down the vinyl siding and creating problems?

thanks.

George

You can vent directly through an exterior wall, a soffit or out of the roof, whichever is easier. If your vent pipe runs through an unheated attic space, you can wrap insulation around it to prevent condensation from forming and running back down inside the vent fan during cold weather.
The key thing is to get an exhaust fan with enough CFM capacity (cubic-feet-per-minute) to clear moist air out of your bathroom rapidly after a shower. Cubic feet of bathroom: length X width X height = CF.)
Same brand exhaust fans may have different size motors, but the fans will look exactly alike. Look on the box, and go with the one with the highest CFM.
You can get one too small, but not one too large.
Good Luck!
Mike

Thanks for the info. I think I'll be going with the soffit/eave vent. Seems like the easiest thing to do. I better get to it, though, before summer's here and going up in the attic is like visiting the gates of hell.

Thanks to all.

George