Use internal dimensions. Shoot for ~105% firebox (FB). It'll tell you what sized throat area to use, although with a center feed it may not be as critical. You may also want to consider adding a shadow plate between the FB throat and baffle plate (BP) to spread out the heat transfer to the center of the BP.
If it's tourist season, how come I can't shoot 'em?
FB is way too big. 18" x 18" x 20" gets you ~103%. When the FB size is adjusted the intakes can be 2 - 2" x 5". The throat also reduces to 52". Chimney to 21".
If it's tourist season, how come I can't shoot 'em?
Any reason the FB cant be taller than recommended? I like the idea, like a drum smoker, of the fire being farther away from the BP. will it hurt if the FB is bigger than 105%?
Up a bit early huh? From everything I have read, the deviation from that sweet spot in FB size causes difficult fire management and that passes through to the tank and either too hot, so you damp it down and it produces heavy white smoke instead of the magical thin blue smoke and a host of issues that usually require retro fitting of size to restore it back to the correct ratio.
The formula of success and ease of stabil use lies in those numbers, on one of my smaller 9o gallon smokers, I did adjust the numbers to allow a taller FB to allow me to raise the inside grate off of the floor a few inches so the dampers line up below the fire.but, they remain at 104%
My 2cents
Make no mistake, there ain't no powder in this Puff ! And... I'm not really a crazy person but I play one in real life
One thing to throw a wrench into the whole process. The calc doesn't really apply to vertical cookers it's for offset smokers. The thing about vertical is the fire/charcoal generating the heat either has to be smaller or another way to prevent all the heat entering the cc. Otherwise it would be way too hot.
Making memories.
Current Smokers: Backyard RF Offset and Hybrid RF Offset trailer rig with Cowboy cooker and fish fryer, always room for more........
Ahhhhh... the sweet spot! makes perfect sense. and the fact that a smaller fire should be used makes sense since it is techniqly a vertical smoker. Thanks for the info. Frank ....Do you have any wise info for me before I go ahead with measurements? Tom?
The same calculator used for offsets is fine also for center feed smokers. The only thing you do differently as you figure whatever you want for your baffle plate divide that in half and split it up between both sides.