View Full Version : Vent holes in house

06-27-2007, 09:54 AM
Hi. I'm moving and adding exhaust vents in my basement renovation. One for the dryer and one for the new bathroom fan. I know that the two cannot share a duct for safety reasons. Does this mean that I have to cut two holes in the outside of the house? I know that seems like a "duh" question, but I'm wondering if there is some way of having the two ducts both empty into the same final, outside opening. Or is that the same safety / code issue?

How do people normally do this?


06-27-2007, 10:12 AM
I don't know the code for this, but I do know that dryer vents often get clogged with lint or bird's nest, etc... So if it gets clogged, you'd be venting the dryer into your bathroom.

06-27-2007, 10:51 AM
Yes, I know about that. I'll just assume you have to cut two holes unless someone tells me otherwise. I'll plan on putting them side by side, I suppose, with separate covers.

06-27-2007, 11:48 AM
Yes, you have to cut two holes. You don't want them right next to each other, either.

06-30-2007, 02:46 PM
Hey Frenchie!

How about using a y connector for 2 different bathroom exhaust fans? Any issue with that? the fans have backdraft flapper, so they shouldn't interfere with each other.

Ever done one as such?

07-01-2007, 10:01 AM
Hya, Chuck!

I've never tried it, but have read (it might've been here, or BT, or JLC, or the Wall), from someone who did try it, that it doesn't work too well.

The way to hook up two bathrooms to one exhaust, would be to use an in-line fan on the common vent pipe, downstream of the join. That way, whenever you flip the switch in either bathroom, air gets drawn out of both... pretty common with central ventilation setups.

The drier vent should never be combined with anything; I think it's illegal in most places, because of the fire-hazard issues (very hot air + lint buildup)

07-01-2007, 11:44 AM
The dryer outlet could also have CO in it if it is a gas fired dryer...you don't want any paths back into the house...you need a dedicated vent for it.

Fantec makes some very nice multi-room venting systems. With the remote fan motor, they are about the quietest system you can install.

I still like my www.solatube.com (http://www.solatube.com) tubular skylight with vent kit...remote fan and free light works quite well.

07-30-2007, 12:36 PM
Yes, you have to cut two holes. You don't want them right next to each other, either.

I'm in a similar situation. Getting ready to add a basement bathroom. The vent for it would be "near" the electric dryer vent.

Is there a code requirement for spacing between dryer vent and bathroom vent? Is there a suggested or "best practice" distance?

Heck, as far as I'm asking - is there a clearance requirement between a bathroom vent and other "features" (soffits, windows, corners, etc?)


07-30-2007, 01:10 PM
There are system requirments for intake vents, fewer for exhaust vents. There are restrictions on placing over walkways, gas meter, electric meter, or within certain distance of windows or door, etc., where you may be exhausting moisture, but I do not know if they are a code issue or rather a common sense one.

WRT intakes, the perfumes, chlorine, etc., that can be in a dryer exhaust, and potentially CO, if gas, should not be near certain areas. But, the exhaust from a bathroom would be primarily an area of concern about moisture - not into the attic for example where condensation could cause rot or other damage.

Hopefully, somebody knows...