Right now my hot water tank and furnace joins into about a 5 inch pipe that enters into the garage and routes up to the roof top. In the garage around the pipe is a 2x4 structure with drywall all around. This is taking up valuable real state. I was in my neighbors garage and realized he doesn’t have the same thing in there. His tank and furnace is in the same spot so I asked where his was vented. Apparently when he got a new furnace installed, they just used some pvc to vent it out the back of the house, and the hot water tank is tied into the vent for their fireplace. Would this be something I could do with my setup? I don’t know what code would be for proper venting of these things. Any enlightenment?
If I recall correctly, once you remove the furnace from the equation of a pair venting to the same chimney, the chimney needs a liner. I believe it has something to do with decreased flue gas temps creating corrosive chemical reactions.
Depending on the age of the furnace, you might be able to do it. If its too old you still can but I think it needs a blower on it to help get the gases out. The CO is what sits in there. It’s the same if you were to get an high efficiency furnace and vent it out the side of the house and leave the H2O heater in the old chimney by itself. The hot water heater by itself doesn’t have enough push to get the gases out. They’ll just sit in the chimney.
New hot water heaters and furnaces are designed to be vented out the side.
Well I will be getting a new hot water tank in a couple of weeks…
They sell the hot water tanks with blowers on them as well. They just plug into a 120vac receptacle. There might be other options as well.
to go the PVC route you’ll need to have a furnace and water heater with low enough exhaust temps…you can’t just vent anything out of PVC.
also as stated if you remove the furnace from vent you typically need to decrease your flue size for water heater only otherwise the cold air in winter will trap the exhaust in the chimney