Square Chimney?

[wombat]

I was wondering how the calculations are affected by using a square chimney rather than round. Do I use the same area or is the square less efficient as a chimney. I figure a square one would be easier to fit into the domed end of a propane tank. Is it also possible to weld it directly to the top of the FB and just open up the side facing into the CC

 

[daveomak]

If the numbers call for an 8 inch round.... use 8" square... that makes up for the corner restrictions....

 

[wombat]

Thanks Dave. How about the idea of welding the square pipe directly onto the part of the firebox inside the dome end. It will make the whole thing a lot easier and stronger.

 

[daveomak]

Weld to the top of the FB then have an elongated opening to the exhaust stack.... that would be similar to the plenum opening... that would work.... I would have the opening between the two from above the lower meat rack to just above the upper meat rack.... that would make about a 10" vertical opening or something like that...
That would make for an exhaust stack that was partially inserted into the Cook Chamber.. Good idea...
I don't know what you would do about the junk that fell to the bottom of the stack and pile up there... Kind of a collect all place... No easy way to clean it out... You could do something like this....

Exh Stk SQUARE INSTALL.jpg

• daveomak
• Aug 16, 2015

 

[wombat]

I could add a cover at the bottom of the opening that can be removed to clean

 

[daveomak]

If you are worried about the stack falling over..... never been a problem that I know of....