The Texas BBQ Forum

Can someone please help me understand? I think I have a grasp on most of the calculations except the Firebox Air Intake??? I have a 24" x 48" cylinder with a 20" x 20" x 18" fire box, 4" pipe chimney x 28.5" lg., 12.5" half moon... I am not understanding the number of intakes & wether a square or round intake should be used. Can someone please explain or draw a sketch on how I should make my Firebox Air Intake so I can get a better understanding. Thank you very much.

milton1allen wrote:Can someone please help me understand? I think I have a grasp on most of the calculations except the Firebox Air Intake??? I have a 24" x 48" cylinder with a 20" x 20" x 18" fire box, 4" pipe chimney x 28.5" lg., 12.5" half moon... I am not understanding the number of intakes & wether a square or round intake should be used. Can someone please explain or draw a sketch on how I should make my Firebox Air Intake so I can get a better understanding. Thank you very much.

The calculator is giving you the desired area needed so you fill in the blanks and see how many openings you need to achieve that area.
Here is a link to the intake numbers I would shoot for. I would increase to three openings because it is better to have and not need than to need and not have.
Link to BBQ Pit Calculator
Here is a pic of my intakes in my firebox door.

Big T on the smokerbuilder board says he puts one on each side, each one equal to the total area needed, so if you have to cook in the wind, you can use the downwind vent. My fireboxes are pipe, so I put the vent in the door. You want them down low, so that the draft has to go through the fire. Doesn't matter if it's square or round, just get the area right. Length multiplied by height = area in square inches