I need some help venting my bath fan in a cathedral ceiling. The bathroom is in the second story, tucked into a loft space. The highest point in the room is about 9′, but slopes down with an 8/12 pitch. Unfortunately we can’t center the shower under the highest point for other reasons, so it is kind of squeezed to one side. The enitre shower will have at least 7’6″ of ceiling height.
My concern is getting the bath fan (panasonic 110 cfm, w/ light) to fit in the ceiling above the shower. The joist bays are 16″ oc so the fan can either vent up towards the ridge or down towards the eave. I would prefer to have it vent down towards the eave so the vent cap on the roof doesn’t interfere with the ridge vent. My concern is the fact that if it vents down, there will be a low spot in the duct that might hold moisture. To clarify, the vent from the fan unit would point down the roof (parallel with the joists) and would need to turn 90 deg. to exit the roof, creating a low spot in the elbow. I planned on using rigid duct.
Is this low spot a problem?
Is there any code rule (or “best practice” rule of thumb) that limits how low that fan could be placed on the sloped ceiling above a shower? At some point, I think it would be low enough that water could splash into it during a shower.
Thanks!
-Rich
Replies
Is the fan meant to be located over the shower? All the bath fans I've dealt with specifically said to not locate them directly over the shower stall.
it has to be on GFI circuit to be in/over shower ... btw nice fan
Which fans are you saying are not allowed in the shower area? provided their are protected by GFCI?A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
Quittin' Time
"Which fans are you saying are not allowed in the shower area? provided their are protected by GFCI?"Not exactly. The code says nothing about it (either using a GFCI or having in a shower).What controls is the manufactures specs.To be mounted over a shower it has to be suitable for wet area use. And that for that listing the manufacture usually requires a GFCI.
Right, that's what i'm asking. Which fans say they are not allowed in a shower area?A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
Quittin' Time
The panasonic specifically states that it is rated for use in a shower stall. I think they also specify that it has to be on a GFCI circuit, but I would do that anyway.I went ahead and installed it with the vent pointing down the roof. It made the roofing work better. I decided that most bath fans get installed with flexible duct and plenty of horizontal runs, resulting in plenty of low spots. The one low spot I will have in my 18" between the fan and the vent cap will probably dry out just fine in the dry Colorado air, even if some moisture did condense there. Time will tell.-Rich
After reading one of the responses above I went back and looked up the directions to the fans I have worked with and saw the GFCI requirement for placement over a shower.
Not sure where I might have seen that you couldn't place a fan over a shower. Glad your fan worked out. Didn't mean to add confusion to your situation.
omni... thanks for comming back & clarifying that
if a bath fan wasn't meant to be installed over a shower, i wouldn't use it
what would be the sense ?
BTW.... given my druthers i would never vent down if i could vent up
we always try to use roof jacks for our exitsMike Smith Rhode Island : Design / Build / Repair / Restore