# Standard Reverse Flow Smoker Calculator... by DaveOmak and others... Ready to use.. rev5.. 6/19/15.

#### MikeFromTexas

##### Newbie
Finished my reverse flow build about 1 month ago. Not wanting to reveal my nerdy innards by performing a flow analysis through engineering software, I decided to follow the recommendations in this thread/tutorial. All I can say is that my pit is a great flowin machine. Great temperature control, temperature distribution and doesn’t seem to use that much fuel (about 12” log per hour).

specs:
45” cookin chamber
18” OD x 1/4 wall.

i’ll say this though, I spent a lot more money than I thought I would. Kinda like when I build ARs..

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Mike From Texas, thanks for the revue of our tutorial... Most folks have found the same...

#### Trus

##### Newbie
Hello Im new to the site and getting ready to build my first smoker. Been smoking on a few types of smokers at academy and such. Anyways, I am looking to build a squared CC Reverse Flow. I started to calculate the dimensions as stated in the thread but im not sure if im doing it correctly. Here is what i have. Please correct me if im wrong.

Cooking Chamber: H= 36" (3ft) W=42" (3.5ft) L=30" (2.5ft)
Ive looked up the conversion for a square box to gallons and this what I have.
cu ft = (3ft) (3.5ft) (2.5ft) = 26.25cu ft
gal = cu ft * 7.48 = 26.25cu ft * 7.48 = 196.35 gal

Volume in cu in = Gallons * 231 = 196.35gal * 231 = 45,3656.9 cu in

Volume of CC (Used Inner Diameter)
H=35 1/2" (2.95833ft) W= 41 1/2" (3.45833ft) L= 29 1/2" (2.45833ft)
Volume of CC in cu in = (35.5)(41.5)(29.5)(0.7854) = 34134.2 cu in
FB/CC Opening in sq in = Volume in cu in * 0.004 = 34134.2 cu in * .004 = 136.537sq in
Area under RF Plate sq in = 136.537 sq in
Area required at the end of the RF Plate = 136.537 sq in
FB Volume Minimum = Volume in cu in * 0.33 = 34134.2 cu in *0.33 = 11264.3 cu in
FB Air Inlet = Volume in cu in * 0.001 = 34134.2 * 0.001 = 34.1342 sq in
Exhaust Stack Volume (ESV) = 34134.2 * 0.022 = 750.952cu in
Stack Length = ESV / 0.7854 (Stack Diameter)(Stack Diameter)
Stack Length = 750.952cu in / 0.7854(6)(6) = 26.5594

Okay im done, Im not sure if the calculations are correct please help me out. THank you

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Refigure the numbers using length of the cylinder, diameter of the cylinder... That's all you need...

Height, width, length are confusing and there are only 2 dimensions to a tank...

#### Trus

##### Newbie
Refigure the numbers using length of the cylinder, diameter of the cylinder... That's all you need...

Height, width, length are confusing and there are only 2 dimensions to a tank...
Thanks for the reply,, if the depth of the cc is 30 in, would that be my diameter?

#### daveomak

##### SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Look up diameter, length etc...