Chimney Adapter Question

Greetings all! Last year I installed an older wood/coal stove in my basement. The house had no existing chimney or fireplace so everything other than the actual stove was new. The stove has an 8 inch flue collar so I used 8 inch triple wall for the chimney and 8 inch double wall for the the stove to the wall. No problems, other than maybe too much draft, I haven't measured it but it's impressive. Anyway, the stove is in the basement and it's not enough to do the job I want it too do so I'm thinking about installing a wood/coal furnace. All of the furnaces I'm looking at have 6 inch collars and I am curious about what, if any, problems I may have connecting such a furnace to a 8 inch chimney. Any thoughts?

Welcome, most chimneys are bigger than 6 inches.

The only true way to check the draft is with a manometer.

Guessing about how well it draws can lead to problems.

Rick

I intend to install a manometer with the new furnace, maybe sooner. I know I have plenty of draft with my current setup, it may be too much but that is easier to deal with than not enough. My concern with the future install would be losing draft due to using a 6" to 8" adapter.

The chimney is completely outside the house and exposed?

As the gasses transition from 6 inch to 8 inch pipe they will expand, losing velocity and temperature.

It's a guess how much until you have a tool to measure it.

In all applications a Monometer, either permanently mounted, or a pocket draft gauge is a very good idea.

If you intend to burn bituminous coal, you should use 8" stove pipe anyway (from the stove to the chimney).

The 6 to 8 inch adapter will be as close to the furnace as I can get it. There is about 4 feet of pipe in the house, the rest of the chimney is outside and goes up about 24 feet.