Paul Franklin wrote:
On Wed, 31 May 2006 19:38:25 -0400, "JA"
wrote:

Would anyone like to weigh in on where I should vent a bathroom fan? (Not
the attic--I know that!) I've found that some home repair sites say it's OK
or preferred to vent through the soffit; others say this is nearly as bad as
venting into the attic and that one should vent through the roof; and yet
others say to avoid the roof and go through the soffit or gable end of the
house.

Does this all depend on where you live? For instance, in areas with heavy
snow, the roof vent could get blocked and therefore venting through the
soffit would be preferred, but everywhere else the roof is the way to go?
Is it really bad to vent through the soffit?


Good advice from other posters. One point I'll add: Keep the duct
length reasonable. The shorter the better. If you have to run 30' to
get to the gable, but can go out the roof with only 5, you are
probably better off going out the roof. Even if you upsize the fan to
allow for a longer duct run, it's difficult to avoid low spots in a
long run of duct, especially flex. Low spots collect condensation,
which attracts dust and may foster mold. And longer ducts are more
prone to condensation because the warm air has more time to cool while
in the duct.

Good luck,

Paul

Whatever website I checked recommended insulating the ductwork to help
prevent condensation. That fiberglass sleeve stuff was cheap enough so
I used it. Don't know how much difference it might make.