I just had new exhaust fans installed in our upstairs bathrooms. I have been laid up with some surgery and had to have a handy man come and do it. I thought it was going to be vented to the out side through the roof. However, the handy man ran the flexible vents over to the soffit and just set them next to a vent. Is this adequate? I am in the mid-Atlantic, so winters are not real cold, but we do get a lot of heat in the summer and cooling in the main issue. Before I start raising the devil with the handy man, I want to be sure he did not do what is accepted in the trade and okay.
Dan Carroll
Replies
Absolutely NOT ok. It must be directed outside. The fan box and seams should be sealed with foil tape as well. Any moist warm air in the attic will condense and cause mold.
"It is what it is."
There are roof jack vents made for this--with a male 4" 'tube' for the flex vent.
Just made a repair to an apartment bldg where the vent was located in the soffit. Made a hell of a mess during the winter months. Warm moist interior air blowing into the overhang caused major damage to the sheathing on the roof and resulted in dirty soffit dust and dirt leaching down the siding. Speaking from years of experience, try to make it run to an exterior wall with the best product possible.If done properly you should not ever need to replace ducting and end up with costly repairs because of bad choices made now.If it cost more money now it will not be an issue later.
Although there are several soffit vent kits out for this type of application, generally it is better to exit the exhaust out a side wall or roof. I prefer a wall, but if the wall is too far away, or not available, go out the roof.
A lot of people do not want to poke any more holes in the roof than necessary, but when done RIGHT, it should not be a problem. I haven't had a leak with one yet, and that includes one from my own powder room.
The consensus reason for not going out the soffit is, that it might not GO out the soffit, dumping moisture into the attic, causing mold, mildew, and icicles in the winter. Another argument is that the air/moisture might be blown out of the attic soffit vent, but sucked back in thru adjacent soffit vents.
Have a sparkling day.
"I am the master of my fate, I am the captain of my soul." Invictus, by Henley.
Note - he did not used a soffit exhaust vent.He just stuck the hose next to a existing soffit intake vent.A guarantee that moisture is not going out..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Thanks Bill, I guess I wasn't clear; my implication was, that even though there are soffit vent kits (not whether or not he used one,) venting thru the wall and roof were more preferrable.
"I am the master of my fate, I am the captain of my soul." Invictus, by Henley.
" I want to be sure he did not do what is accepted in the trade and okay."
well ... he did do what's accepted in the trade ...
but no ... not OK.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
Accepted or not don't do it. For many reasons this creates issues related to moisture. I always come out of the fan box at an angle that will leave me with a downward pitch on rigid pipe. Keep the seams up an seal all with aluminum tape. I prefer exiting thru a side wall ie. a gable end. Do not use FLEX. I just did an install using a Panasonic unit designed for thru the wall. NICE product no duct work except for whats provided. And quiet.
What you have now is the damp problem moved to the attic! Look forward to mold in the attic.
The damp air should be pushed outside, duct should be insulated so the warm air holds the moisture till its outside. Fan unit should be sealed to the drywall to make sure it sucks air from the room.
Job just needs finishing!
Thanks for the input. Gable ends are too far away to go that way. When I talked to to him I mentioned going up and out the roof, and he suggested the soffit (Fairly short run). I am going to keep my words short and sweet but let him know this is not what I wanted, and come back and put the vent out the roof. It is funny because I had him in to replace and repair the seals around other pipes going through the roof. I had a chimney sweep in a few weeks back and he spotted place where the cowling around some vents had developed holes (no leaks yet) and I called the handy man in to fix them and at the same time to make care of these fans that had been vented in to the attic by a prior owner. I replaced the fans with new ones that move a a lot more air.Dan Carroll
As noted, that is a bad practice. It would be better (but not real good) to remove the duct entirely - he's guaranteed condensation and mold growth on the roof sheathing.
Best is to vent directly outside. In NW Ohio, it works to nail the exhaust duct off just below a through roof vent.
Remember Mary Dyer, a Christian Martyr (Thank you, Puritans)
http://en.wikipedia.org/wiki/Mary_Dyer
May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
I disagree. You really need to isolate all the moisture form the attic. If you have to use an existing roof vent, I would make a collar so I could seal the vent to the duct.
No, No, No. You need to vent an exhaust fan through its own dedicated vent sealed to outside. If you're running the vent line through unconditioned space you should use insulated flexduct.
Give your handyman my card, i'd be happy to make a ton of money coming behind him and cleaning up his messes.
Flex duct, whether insulated or not is a poor product to use. Better is thin-wall 4" PVC drain pipe; has smooth walls that won't trap moisture like flex can and does. No sway belly either that pools vapor into standing water.
The PVC pipe can be gently sloped towards the outside exit (if not using a roof vent). Wrap insulation around the pipe after carefully sealing with proper tape - DO NOT use duct tape. Duct tape will dry out and fail.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Never heard of anyone using the PVC. I use metal tape to seal joints, duct tape is not up to the job. Seems to me like moisture will condense on the wall of the duct regardless of what its made of.
I use PVC as well. It is easier to work with and cut up in the attic. Easier to seal as well.
"It is what it is."