B vent verticle rise?

[Jim H.]

I originally thought i could change out the fire box area inside the stove to direct vent or vent free. i have a desa napolean
propane with top vent. moved it upstairs and sits under a mantle for looks now. for me to run
the pipe that came with the stove i would have to move the stove out into the room to far for our liking.
i was wondering if i can run a verticle insided run only a foot up or so before going thru a wall thimble and out and up
the outside of the house? seems as though i cannot change out the stove because they are all coded with
serial numbers? it has the cast iron body in which what ever fire box you want can be put in.....so why not
a change out....? i have countless calls and emails into desa and a dealer....so anyway, just curious to any other
ideas. this is not our main heat, we did install the xxv pellet downstairs. thanks...

Jim

 

[PaulRicklefs]

Yes you can run the b-vent somewhat horizontally with a bit of rise towards the base-t that you would install on the outside of the house. You would need to purchase an appropriate wall thimble to protect the house where it cuts through. As well you will need to make a chase to go around the vertical vent on the outside of the house to help insulate it. If you do not insulate it properly you will likely not have enough draft on a cold day and you would backdraft allowing CO into your house. You will also need to make sure the vent termination is at least 2' above the highest point of your house.

It is quite a bit of work to do this job but i'm afraid it is your only option at this point unless you can locate a proper stainless chimney liner that you could install up the existing chimney.

Your best bet would be to locate another place for your stove and run a new vent up through your attic with the proper thimbles and nessary hardware.

Good luck on your venture..

 

[Jim H.]

thanks for chiming in. i was going to look for a double walled "B" vent (if there is one) to do the run outside. Is is a definate on the run
all the way past the roof? I have the xxv pellet stove already in the chimney downstairs using a top vent option on it...so going into the chimney
is a no go upstairs i would think. this thing might just be a decoration this year till i get it figured out or a similar unit that is direct vent like my fireplace was.....
Jim

 

[PaulRicklefs]

thanks for chiming in. i was going to look for a double walled "B" vent (if there is one) to do the run outside. Is is a definate on the run
all the way past the roof? I have the xxv pellet stove already in the chimney downstairs using a top vent option on it...so going into the chimney
is a no go upstairs i would think. this thing might just be a decoration this year till i get it figured out or a similar unit that is direct vent like my fireplace was.....
Jim

Well B-vent is a double walled vent but it is only air-insulated. Most b-vent is run through a chase up through the middle of the house allowing the warm air of the house to help maintain draft and gas temps. If you run it outside you will cause the gas to condense before exiting the chimney causing acidic corrosion and poor draft. Building an insulated chase will help, but you are still losing the benefit of the house temps assisting the vent. It is still much better than nothing though.

You definitely need to extend it 2' above the roof or you will not have sufficient draft.

See you,

 

[paulslush]

You will need more than one foot straight up from the top of stove. I believe 3 feet are recommended. The warm flue gas need that straigt up vertical run to gain momentum an start flowing. I saw an install where they put a 90 right on top of the stove and it did not work. Had no draft.