Given that theory, (which doesn't make sense) then you could get a 12" pipe
up my flue. And the area of a 12" circle is over twice that of the area of
an 8" circle. AND the area of the 12" square is almost THREE times the area
of an 8" circle. So, believe me, a 12" flue makes a hell of a lot more
draft than that of an 8" pipe. This was confirmed when i finally dropped 8"
single wall pipe down my chimmey and hooked it directly up to the stove
insert. No more raging away when i open the doors.

but thanks for playing,


steve

wrote in message
...
On Jan 17, 9:26?am, "S. Barker" wrote:
It is possible to create too much draft. ?But going up just one pipe size
won' t do that. ?I have a fireplace insert with an 8 inch outlet and my
chimney is 12 inches square. ?Sometimes when i open the stove doors, ?it
just goes ape! ?Also the smaller pipe will stay cleaner due to it's
running
hotter.


the effective size of a square or rectangular chimney is the largest
circle that can fit inside, so your 12 inch square isnt as oversized
as you might bellieve