Can I vent a dryer from the same mechanical closet as a water heater.? [solved]
I'm currently looking at a condo to purchase and the existing "closet" that contains the plumbing and venting for a washer/dryer is a bit on the small side. It's probably not that big of a renovation to expand that space given the layout, etc, but there's also a small room that holds units gas water heater.
I'm wondering if there's likely any SAFE way to house the washer/dryer in the same space as the gas water heater, being able to share the venting between them. I'm not optimistic that it's doable, but figured it didn't hurt to see some opinions.
Very likely not.
The codes around heating and cooling are very specific about the sizing of vent pipes - if the pipe is too small, you'll get back pressure and carbon monoxide issues. If the pipe is too large, you'll get condensation issues.
Adding another appliance to an existing vent pipe (whether a chimney or a PVC pipe) will almost certainly put it out of code compliance.
An alternative is you could get a non-venting dryer like the one I had in a previous condo. It is slower to dry and your clothes come out wrinkled a lot but it's better than trekking to the laundromat! Oh yeah and no building code violations! :)
Just to pile on - using the furnace vent for dryer exhaust ducting is a definite no-no.
Dos & Don’ts of Laundry Plumbing - The Building Expert - 2020