Lesser of two evils/ vent fan?

Users who are viewing this thread

ray ely

New Member
Messages
2
Reaction score
0
Points
1
Location
Kentucky
I'm mounting a vent fan in a bathroom and made my roof penetration too close to the fan. I thought the least amount of pipe would be preferable but now see that the vent fan calls for 2 feet before the first elbow. The fan location can't be moved due to the bathroom configuration and I don't want to make another penetration in the epdm roofing and try to patch the hole. The roof is a cathedral roof on a dormer addition with not attic space above, 8 inch joists.

Right now, the vent just goes about 6 inches then an elbow facing up into the external vent hood on the roof.

The only way I could get more pipe into the picture would be to run away from the vent hood, then two els back to back to return to the vicinity of the penetration, then elbow up.

I assume the requirement for two feet of pipe is related to noise, but it seems like adding 2 elbows would also create restriction.

I would appreciate any thoughts on this. The fan is a 110cfm Panasonic.
 

Smooky

In the Trades
Messages
2,299
Reaction score
152
Points
63
Location
North Carolina
Do not add any extra turns. You want a straight pipe out or only slight angles or turns to get the best flow. The length is not so important. Don't worry about the 2 foot requirement before the first turn. A short pipe and a slight angle would be fine.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks