Edit: 2-16-2014 ; You will need a hand held calculator, smart telephone, or your computer.... calculator, to use this tutorial.. It does not crunch numbers for you.....
Calculations for a standard design, reverse flow smoker..
Gallons X 231 = volume in cubic inches.... Sometimes the tag, in gallons, reflects a 20% air space for expansion....
Volume of the Cook Chamber.... Use the Inside Diameter of the tank...
Diameter X Diameter X 0.7854 X Length = Volume in cubic inches
Volume in cubic inches X 0.004 = FB/CC opening in square inches
Volume in cubic inches X 0.004 = Area under the RF plate in square inches
Volume in cubic inches X 0.004 = Area required at the end of the RF plate in square inches
Volume in cubic inches X 0.33 = minimum volume of the Fire Box
The above areas are necessary for great air/heat/smoke flow.... using less may cause an overheated FB.... Narrow / Long CC may require an increase in those numbers due to increased surface area friction to volume... Wide/Fat Short CC may use smaller numbers due to reduced surface area friction to volume...
Volume in cubic inches X 0.001 = FB air inlets in square inches...
Recommended upper and lower air inlets... Upper air inlet directly across from the FB/CC opening to facilitate moving heat from the FB to the CC, and insuring good air flow through the CC.. The lower air inlet should be situated at or below the fuel grate.... The two air inlets can share the designated square inches of opening....
