Combined Vents

carl_6

Anybody know anything about combined vents for 90% (condensing)appliances?

I know this is a fairly straightforward thing for 80% with b-vent (there's a table in the back of most every catalog), but I'm having some trouble finding out about doing this with pvc.

I've got an existing Trane "XV90" furnace, 100 MBH, with a 3" flue out the side wall. I want to add a 50 Gallon (~120 MBH) "power vent" domestic water heater.

Can I just chop a wye into the existing flue? Maybe add a relay to lock out one while the other is firing? I don't really have the space to add another pipe, and I'd really like to avoid chopping more holes in the house, if possible.

Thanks..

John T_2

CO

Sounds like a rather dangerous proposition to me. Carbon monixide is extremely lethal as are fuel gases if not dealt with properly, by a qualified individual. You may want to check out the link on this site "Find a Contractor" and keep everyone safe.

Mark Hunt

DO NOT DO IT!


You can't vent both units through one pipe.

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Dale

Not a good idea

Or legal either depending on where you are. And, both of the appliances you mentioned probably won't work if you do. I think they will sense the pressure of the vent combination and fail on pressure switch sensing, and the water heater isn't designed for condensate drain. You have devices that must be vented to manufacture specs, if you expect them to work you'll need to follow the directions.

Glenn Harrison_2

You cannot do it!!!!!!

Any appliance vented with PVC must use a separate pipe for each appliance. Combining of pipes is forbidden. DON'T DO IT!!!