Chimney Size

[1badsapper]

A while back there was a post on how to determine the size of the area needed under the chimney so you get good draw. It was a formula (algebra) that I am looking for. I wrote it down but lost it some how.
Thanks
Ric.

[MapleME]

Ric, are you meaning stack size (length?)

The rule I have always been told was at least double the length of your pans...so 6 foot pan= 12 foot stack minimum. Not sure if this is what you meant... so if not, just ignore it :)

happy holidays!
Josh

[1badsapper]

Thanks for responding Josh, What I am looking for is how much space should be left below the pan on the slanted part of the part of the fire box on the chimney end . Like 3" or 4". There is a formula a guy used on here I just can't find it.

[SeanD]

It's the area of your stack: A=3.14 x r x r.

r is the radius of your stack. So a 6-inch stack has a surface area/opening of 3.14 x 3 x 3 = 28.26 sq. in. An 8-inch stack is 3.14 x 4 x 4 = 50.24 sq. in.

The cross section of the space under your pans is rectangular, so its area is just l x w. Since the width is fixed, the length or height of your space can be found by dividing your stack surface area by the width of the inside of your arch.

So if the width of the inside of your arch (brick to brick) is 20 inches and you have an 8-inch stack, just divide 50.24 sq. in. by 20 in. to get 2.5 inches for the height of your space under your pans.

That was easy. Now if there was only an easier way to get the kids asleep, so Santa can make his stop and be on his way. :)

Sean

[1badsapper]

Thank you Sean, that was the formula I was looking for!
You have saved the day.
Thanks Again
Ric.