Wood burning Furnace Questions??? With Pics

[Hiram Maxim]

I'm considering putting in a wood burning furnace and had some questions from some of you folks that know your stuff.

In my basement I have a 85% efficient natural gas furnace and a natural gas water heater that exhaust into a 8x6 masonry chimney.

I use to also have an oil burning furnace(back up) that used the same chimney (see cover plate) before it was recently removed.

I'm wondering if I could exhaust a wood burning furnace into the same chimney?

Thank you,Hiram









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[Hogwildz]

Technically, nada.
One appliance per flue.
The reason being, even if the flue can handle the volume of both, assuming it can. If one is running, and the other not, the toxic gases can down draft into the one not being used, thus venting back into the home.
Now adding a wood burning appliance on top of the other 2 in same flue. That may be asking for trouble. Do folks do it? Yes some have stated they do. I would def not add the wood burner to that flue though with the other two existing in it also. You could get power vents for the other two appliances though, and then vent the wood burner into that flue by itself, if the cross section is within limits.

 

[Hiram Maxim]

Thanks for the reply!

Just a thought.....

Back to the drawing board.

I don't take chances :cheese:

 

[karl]

It's doable. The water heater will have to go. It should probably go anyway. You could switch to a tankless electric and use a water coil on thee wood furnace to preheat the water. Your current tank could be the storage tank for the water from the furnace. You can get a wood furnace that has built in gas burners. Now you have one appliance in one chimney, with gas backup.

 

[Shari]

Am I misunderstanding something with your current set up? Do I see that you have water heater and furnace currently exhausting into the same flue? If yes, do these two meet current code in your area?

Shari

 

[Hiram Maxim]

Am I misunderstanding something with your current set up? Do I see that you have water heater and furnace currently exhausting into the same flue? If yes, do these two meet current code in your area?

Shari

Shari,
Its only been set up that way sense 1953.......... ;-P

 

[CrappieKeith]

Still it's illegal.Unless they are connected by a single manifold prior to be connected to the flue as per NFPA .
Wood/oil or wood gas can be vented in a common flue as long as both fuels are burned in the same appliance and that appliance is tested and listed to operate that way.Also if it is wood gas the unit must have a fume sensor to recognize a sustained backdraft or flue spillage or blockage which will shut the unit down if these things occur.

 

[Hogwildz]

Am I misunderstanding something with your current set up? Do I see that you have water heater and furnace currently exhausting into the same flue? If yes, do these two meet current code in your area?

Shari

Shari,
Its only been set up that way sense 1953.......... ;-P

I'd say that falls under the "grandfather act"
Bro, even with the current set up, I highly suggest some detectors around that area. Better safe than sorry.

 

[Highbeam]

We see combined chimneys for gas appliances all the time. Usually the water heater and furnace share the same flue, neither being power vented. That's how my last house, built in 1999, was set up.

I wouldn't add a wood burner to the same flue though.

 

[johnn]

We see combined chimneys for gas appliances all the time. Usually the water heater and furnace share the same flue, neither being power vented. That's how my last house, built in 1999, was set up.

I wouldn't add a wood burner to the same flue though.

I have this set-up above, originating in the basement, only the gas furnace has its own liner inside the chimney. How does if any, does this change the dogs bite from the original question?