Bathroom Fan in 20x30 x 1-1/2

[Micky]

I am wrapping up the siding on my 20 x 30 cabin. http://pg.photos.yahoo.com/ph/merritt000/album?.dir=a3d6&.src=ph

I am curious the best method to vent the first and second floor bathroom.  I am going to put on a metal roof and going to get a bunch of snow.  So, I want to avoid going through the roof.

The first floor bath is on an outside wall and has an exposed beam sealing.  I would think the only place to put the fan is high in the wall.  But, I don't want to see the vent in the middle of the exterior wall.  I could either pipe up to under eaves or down closer to ground.  The problem with up is I don't want to put moisture under eves.  The problem with down is that it may be hard to force hot air down?  Any suggestions?

Second floor bath is also on the outside wall but it is under a cathedral ceiling.



I could put the fan on the wall but it would only be about 3' off the ground.  If I put it high I would have to go through the roof or the pipe down to under eves.  Any suggestions?

[Shelley]

I have no experience with your climate, but I read discussions like this all the time at Fine Hombebuilding.

Consensus is venting underneath the eave is bad for the reason you mention...not to mention ice dams.  You might investigate a multiport fan.  FanTech is a great brand.  There are others.

 Motor is in the attic.  No noise.  Only 1 roof penetration.  If there's an operable window, vent was not necessary under UBC.  Don't know about IRC.

[Micky]

That may be an option.  Would a fan like that work to pull air from a first floor bath all the way to the roof?  That is a prety long path.

I think I am going to chicken out and skip the window in the upstairs bathroom.  I was thinking of a sky light, but we get up to 5' of snow where I am.  I am concerned about leaking with all of that snow.

Does a bathroom roof vent work with snow on top of it.  This is going to be used very little in the winter.  I am worried that the vent will keep the snow from sliding.  Then there will be snow over the vent?

[Shelley]

Wow!  5' of snow.  We have a few people from New England, maybe they'll have more experience.  But, NE really not the same climate.

But, once-upon-a-time I lived in Durango, Co.  Similar.  Altitude, UV, dry light snow for the most part.  Had my first metal roof there.  12:12 pitch if I remember.  Steep at any rate.  Absolutely no snow on the roof.  Builds to a certain point, then whoosh.

Don't think one vent stack is going to be a problem.

First time I used FanTech, couldn't buy locally.  Bought from a company with a web site.  EMI, maybe?  I can find it if you want.

Guys on the order desk very good at getting me what I needed.  Different models depending upon number of ports, SF of rooms exhausted and length of duct runs.  Biggest problem is getting a switch to turn it off since there's almost no sound.  They sell those too.

Remember, advice worth amount paid

[Dan]

The problem with that snow going woosh, is anything sticking out the roof will want to go woosh along it.  Put any roof penetrations as near the peak as possible, if not right through it.  I know people who every year have to try and come up with a new way to divert the snow around their wood stove pipe because the snow keeps taking it off.  Amazing how much noise and shaking 2-3 feet of snow sliding off your metal roof can make.  Oh, one other thing, you don't want a door underneath all that snow either.  The multiport fan is perfect for putting the vent at the peak.  On a brighter side, I know many people who have skylights in major snow country with no leaks, just make sure it's installed correctly.

[John Raabe]

One house I designed in Leavenworth, WA (7' of snow some years) had every vent, chimney and exhaust fan run through the roof inside a big wood framed chimney covered with a metal cap open on all sides. This kept the roof penetrations to 1.

[Amanda_931]

Sounds like a good idea.

Ken Kern thought about running the makeup air for the masonry stove down beside the chimney to try to warm the incoming air--wouldn't want to overdo that, though.