Fire Box Sizing

Discussion in 'Wood Smokers' started by deke77, May 23, 2009.

  1. I'm beginning my first home made smoker. I want to use with either wood or charcoal and I have a 60 x 30 tank for the cooking chamber. What is a good rule of thumb for sizing the fire box? I didn't want to build one too small but I also want to be fiscally conscious and not over-size if I don't have to. Any suggestions?

    Thanks,

    Deke

    ECB with AfterBurner
    Brinkman Smoking Pit
     
  2. bigsal51

    bigsal51 Smoke Blower

    1/3 the size of the chamber
     
  3. jamesb

    jamesb Smoking Fanatic

    1/3 size of cook chamber is a common rule of thumb, but not always practical. For instance, on my 8' x 48" pit the firebox is only 30" x 24", on my 8' x 30" reverse flow the firebox measures 30" x 26".

    On your pit, I would go with about 30" x 24"... Just guessing here...

    Best of luck with your build!
     
  4. randy1439

    randy1439 Newbie

    Pa.
    I'm so confused I'm building a return flow smoker, my tube is egg shaped, measures 21" high inside, and 28" wide inside, and gonna be 8 ft long. I'm still not sure about size of firebox, and size of smoke stack, I tried that pitt calc. still not sure if I did it right, any help with this whould be great.
     
  5. randy1439

    randy1439 Newbie

    Pa.
    I come up with 27.5" x 28" firebox and still working on stack size and draft for mine.
     
  6. randya

    randya Meat Mopper SMF Premier Member

  7. randy1439

    randy1439 Newbie

    Pa.
    Thanks, when I get it going, I'm sure you will be hearing from me. (help me, help me) lol.  I will try to get pics on here too. thanks for the info.
     
  8. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    The pit calc may be hard to get good numbers from on a tank that isnt round or square.

    I think I would take the 28" wide number and use it as if the thing was round and not egg shaped. Its going to make the numbers a little high but you can always damper down vs if you make the holes to small you can only open them so much.
     
     
  9. randy1439

    randy1439 Newbie

    Pa.
    I ran a tape measure around it, and found a barrel the same measurement around, so I came up with, if it was'nt egg shaped, it would measure 26" inside diameter. But you are right, I can't see where I could go wrong if I just go with a size that I know is bigger than I need. Thanks again don't be afraid to shout out, I'm always open for opinions.
     
  10. randy1439

    randy1439 Newbie

    Pa.
    I got a question ? On a return flow smoker, mine is gonna be 6 ft long, I decided to down size it a little. When i put the plate in for the smoke chamber, how much space at other end should I leave open, for the smoke to go up through and return.
     
  11. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    I made mine a few more square inchs then the opening from the firebox to the cook area.
     
  12. randy1439

    randy1439 Newbie

    Pa.
    Ok thanks, that makes sense, I was'nt sure about that, so figured I better throw that out there.
     
  13. sqwib

    sqwib Smoking Guru OTBS Member

    Randy make sure to post pics of your progress and talk it up, sometimes a mistake will be caught before its made.

    I know when I built mine, its success was mostly due to the good folks on several forums.
     
  14. randy1439

    randy1439 Newbie

    Pa.
    Oh I will, I sure I'll be needing lots of help from everybody, I did'nt get started yet, I'm only getting started cutting parts, It will be a while before I get started with the build part, but thanks for taking intrest.
     
  15. randy1439

    randy1439 Newbie

    Pa.
    Im thinking about putting a smoke stack on both ends of my return flow smoker when I build it, because I think if I don't when I open the door to check on what i'm cooking, I think smoke will be pouring out in my face. So i think if I had another stack on other end, that I can open up when I open door it will cut down on all the smoke. Would this be a good idea or not.
     
  16. randy1439

    randy1439 Newbie

    Pa.
    [​IMG]
     
  17. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    I would only do it as a place to dump heat or increase the draft in the event of low temps and you want to build the fire fast.

    The smoke is going to follow the path of least resistance. That said unless you install an evacuater fan its gonna end up right in your face.

    One thing that will help is don't mount the rig to low, smoke rises.

    I like to be able to hold my arms out straight in front of me and work on the top shelf.

    Just like my tables, my smoker is not short people user friendly. It only works for us tall lanky folks.

    I'm not pickin on the short peps, sometimes it really sucks being tall. Trust Me.
     
  18. randy1439

    randy1439 Newbie

    Pa.
    Yeah, I didn't think of that, mine gonna be mounted pretty high too, thanks.
     
  19. randy1439

    randy1439 Newbie

    Pa.
    Being my tank is odd shaped,from the fire box to the smoke chamber I need 129.02 sq inches, the pit cal. does not show me what i need to know. If my tank is 28 inches inches high and it's 21.5 inches wide, if I just go with a 1/3 of the size for the smoke chamber. Which means the plate will lay in about 9.33 of a inch from the bottom, will that give me enough for the smoke chamber, I have know clue how to figure out how many square inches is in something D shaped.
     
  20. tom37

    tom37 Master of the Pit OTBS Member SMF Premier Member

    If you make the opening from the firebox to the cook area 20 inchs wide by 9.33 inchs deep and its a sideways D shape you will have an area of  143.93 sq inchs.

    If you make an opening 18.5 inchs by 9 inchs tall in the center you will have an area of  129.81.

    Just making sure this is what you are talking about. The half circle area is the number you need to be close to 129.02. Correct? And also is this kinda what the end view will be on your smoker or is the egg part laying down?

    [​IMG]
     

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