Ducting and plumbing question

fallen1817 · #1 03-16-2015, 11:11 AM

Hey everyone,

In regards to finishing my basement, is it "to code" to run my bathroom fan in my basement to my furnace exhaust and splice it in with a t joint? I don't want to have to punch a new hole through the foundation wall to vent it.

Also, is there a plumber in the Edmonton area on here that would be interested in coming over and doing a consult for me?

Thanks fellas.

CaberTosser · #2 03-16-2015, 11:19 AM

That would be absolutely wrong and quite frankly its a smack-worthy proposal. You'll need a hole cored through the foundation or drilled through the rim joist to accommodate that exhaust, there's no short cuts to safety.

Running a bath fan through a chimney.... I just don't know what to say to that without getting an infraction from the mods

One time I encountered a luxury home in a big money heritage neighborhood (Mt Royal) with a nanny suite in the basement that had mold problems. I checked that the bath fan was working, that was ok but the grill was rather linty, then I checked how its exhaust pipe was run. The run was quite long, much more than usual, but 25% of the way to its exit there was a junction in the pipe which I followed to their clothes dryer. Being that the developed run to the bathroom was shorter than the run to the outside of the house the dryer was exhausting back into the bathroom, creating the excessive humidity that resulted in the mold. The lint it built up in the bath fan also reduced that fans effectiveness. They got a new hole cored and a separate exhaust. In this instance someone had shortcut to an existing pipe as one room was newer than the other (I can't recall which)

bat119 · #3 03-16-2015, 11:26 AM

Yikes!

Your next dump could be your last

CaberTosser · #4 03-16-2015, 11:42 AM

There's one way that you could, so I should describe that situation:

If you had a new furnace installed and had its direct vent 636 PVC chimney and air intake cored through the foundation wall, with a new water heater that is also direct vented out through the foundation wall then you could use the abandoned b-vent chimney for an exhaust. That's the only time. I figured that I'd cover that angle, just because its possible.

fallen1817 · #5 03-16-2015, 11:44 AM

Well, at least I asked lol. Looks like I'll have someone come out for a consult for that, too. I've got no experience with the ducting, so I figured I would ask. My logic was pretty much "they're both exhaust, so why not?"

It would have been rejected when I applied for permits anyways haha

Thanks again, guys. And thanks for not smacking me, Caber

CaberTosser · #6 03-16-2015, 11:49 AM

Quote:

Originally Posted by fallen1817

Well, at least I asked lol. Looks like I'll have someone come out for a consult for that, too. I've got no experience with the ducting, so I figured I would ask. My logic was pretty much "they're both exhaust, so why not?"

It would have been rejected when I applied for permits anyways haha

Thanks again, guys. And thanks for not smacking me, Caber

I had to suppress a lot of sarcasm, I think I need some tea

Good on you for checking before doing it though. Even research online can be hit & miss with some people posting YouTube how-to's who should be imprisoned for impersonating competency. There are however some good ones as well, its finding the difference where the trick is for the amateur/viewer.

fallen1817 · #7 03-16-2015, 11:55 AM

I might have worded it poorly, but maybe it doesn't change anything.

I was referring to the exhaust fan that you run when you go number two, not the vent stack for the toilet. I'm not sure if that will make a difference in the triviality of the question but I've read a bit more and think I might have poorly represented the question. Does that change anything? Or no?

CaberTosser · #8 03-16-2015, 12:02 PM

Quote:

Originally Posted by fallen1817

I might have worded it poorly, but maybe it doesn't change anything.

I was referring to the exhaust fan that you run when you go number two, not the vent stack for the toilet. I'm not sure if that will make a difference in the triviality of the question but I've read a bit more and think I might have poorly represented the question. Does that change anything? Or no?

Nope, that's exactly what I thought you were proposing. Either would be very incorrect anyways.

Sneeze · #9 03-16-2015, 12:07 PM

Quote:

Originally Posted by fallen1817

I might have worded it poorly, but maybe it doesn't change anything.

I was referring to the exhaust fan that you run when you go number two, not the vent stack for the toilet. I'm not sure if that will make a difference in the triviality of the question but I've read a bit more and think I might have poorly represented the question. Does that change anything? Or no?

No...

You can not run a bathroom ventilation fan into the main exhaust of the furnace. Your bathroom fan needs to be ducted into the joist/truss space and vented to outside.

Use an insulated flexible duct to help control condensation in the duct.

thumper · #10 03-16-2015, 02:32 PM

[QUOTE
I was referring to the exhaust fan that you run when you go number two, [/QUOTE]

Try it! With your bathroom fan pushing your personal methane exhaust into the furnace, you might save on your natural gas bill!

CaberTosser · #11 03-16-2015, 03:16 PM

Picture this possibility, you're running the bath fan that someone tied into a chimney and perhaps you have an older furnace that utilizes natural convection for its exhaust (no fan assist), perhaps its a sizeable fan and its creating a bit of pressure in the chimney. Then the furnaces fires and instead of exhausting up the chimney due to the mechanically induced positive pressure it not just spills out the draft hood instead. Maybe the furnace is older and has no draft hood safety switch (or the switch is stuck). Now all the exhaust is pouring into the house instead of the chimney. Maybe the bath fan was left on right before people went to bed. Now the family wakes up to find they've died during the night, a la Monty Python "But I didn't eat the salmon!"