can a fan exaust duct be vented at soffit? can any type of venting, terminate at the soffit besides the auxillary drain for the a/c.
It’s a poor technique but allowed by most AHJ’s. They do it here all the time…:twisted:
[quote=jschmidt2]
can a fan exaust duct be vented at soffit? can any type of venting, terminate at the soffit…quote]
It can not, unless it penetrates the soffit to the exterior, around here.
The problem with venting at soffits is they are difficult to put back draft dampers in----because of gravity:D :D. There are soffit vent caps made though that do have a back draft damper----but they are not as readily available-----at least at the big orange tool box. And, of course venting at screened soffit vents is definately a no-no and will result in the moist air ending up in the roof/soffit structure.
Here’s what I see everyday…
To the exterior so legal, but the laws of thermodynamics tell you fairly ineffectual… 
It’s not a good idea. It can suck the moisture back into the attic space.
Being vented through the roof or outside wall is not enforceable unless house was built after adoption of 2006 IRC.
If the soffit provides roof or attic ventilation, it isn’t a good idea, as several have noted, but if the soffit is not vented and the installation is proper, it is perfectly acceptable.
Where are they available?
We have 2 baths that are gutted to the studs that we will be building back starting this Monday. Neither bath had an exhaust fan before and we are going back with exhaust fans in both. The basement bath has a 10" block exterior wall. For that bath, we are planning to go into the ceiling, over the block and through the rim joist and brick veneer to go out the side of the house … this avoids going through the block. The other bath is directly over the basement bath where we are planning to go into the attic and over to the soffit. Our overhang does have soffit vents for attic ventilation, but we are planning on running duct from the ceiling fan to a new soffit vent just for the bath exhaust.
What is a better solution?
Here is a company for you. You may have to contact them to see where you can get them.
Close 
They forgot to replace the duct tape periodically.
I recommended an upgrade to “Coat Hangers” Michael.
See them all the time at Home Depot and Lowes.
Interesting that you picked up this company. did work at the owner’s home 20+ years ago. It was a small local company in Richibucto, New Brunswick then and now I see he’s into the US and Asia now.
Just checked the history- great story of entrepreneurship!!!
If you’re not getting out of the attic, anyway, I’d rather see the ducting attached to a collar tie (or similar) and ‘aimed’ at the ridge vent 10-12 inches away - that air is going ‘outside’ even though it’s not ‘terminated’ outside.
And yes ‘they’ allow that here as well…
Let the arrows fly … 
A client this week was someone that was displaced from his home (apartment) due to a fire in the building. Fire (reportedly) started in a Bathroom exhaust fan that terminated within the Attic. Firewalls between units (reportedly) terminate at the third floor (do not pass/continue thru attic to the roof).
http://images28.fotki.com/v987/photos/1/1125527/5359912/DSCF0210-vi.jpg?1189059130
http://goodfellowship.fotki.com/incidents/jefferson-at-westto/
Kansas City area. National Code says outside - local code guys say if attic is ventilated dump them there. We see it all the time. Usually just the vents run up into the attic and terminated by:
laying on the insulation; going to soffit vents and just laying there in the attic (no fancy deflectors outside, etc); or going to a rafter and being nailed under a roof vent.
That’s what they do here in SC alot… nail it up next to the ridge vent and move on…:roll:
As is the general thought, ventilation of a bathroom into the soffit is a bad idea. How does this differ from direct ventilation into the attic as it will essentially be drawn right back into the attic? Just a thought - with any ventilation system, i.e., bathroom, dryer, is the duct too long to be effective for the cfm of the fan/motor?