My house has a main chimney primarily used for the first floor
fireplace. This big old fireplace was originally used for cooking when
the house was built. This chimney is the old, non-lined, wide-open type
and it has a stove pipe that accesses it on the second floor. The
chimney has a large flag stone on the top to keep rain out. The second
floor stove pipe just sticks out a few inches into the chimney. I have a
woodstove connected to that second floor pipe. My concern is that this
woodstove is exhausing into a large chimney and this creates a lot of
creosote. I have read that having woodstove smoke output into a large
chimney can cause creosote buildup since the smoke hits the walls of the
relatively cold chimney and leaves a lot of creosote. When I stand in
the fireplace and shine a flashlight up the chimney I can see shiny
creosote on the walls of the chimney starting just above the stove pipe.
I'm leery of a chimney fire.....
I'm thinking to make the setup safer I might: 1) put in two stainless
pipes in the chimney and 2) put in a woodstove in the fireplace instead
of using it as a fireplace. In this way, I would have metal all the way
to the roof with two separate pipes for each source of smoke. The only
somewhat tough part is what to do with the second floor stove access.
I'm thinking that I could put in a pipe for that stove, but run it all
the way down to the first floor and just access it with a "T" on the
second floor where the stove exhaust would access the pipe. In this way,
I could clean this pipe more easily from the first floor. Otherwise, it
would be almost impossible to clean the pipe since it would have a 90
degree elbow where it entered on the second floor. I'd appreciate any
comments from those who have tried putting pipes in a large chimney and
how this has worked for them.