# Fire Box placement

Discussion in 'Side Fire Box' started by bhawkins, Dec 10, 2012.

1. ### bhawkinsSmoke Blower

Hi, new here and trying to modify my offset smoker. The fire box that I originally put on was way too small. I really had no idea what I was doing, but was trying anyway. I am in process of replacing the firebox with a nice square one. I was wondering if there was a certain height in relation to cook chamber that works best, or as long as the heat exchange  opening is clear is that good?

2. ### daveomakSmoking GuruOTBS MemberSMF Premier Member

Hawkins, morning.... I read on your other thread, you are planning of building a RFS.... Is that still happening here ?? Below are 2 threads with some great plans and needed info for making a great smoker....  These should answer most of your questions.... We are always here to help with the specifics of a build.....   Dave

http://www.feldoncentral.com/bbqcalculator.html

http://www.smokingmeatforums.com/t/54542/building-an-italian-offset-smoker

firebox = 1/3 of cook chamber

firebox volume X 0.008 = firebox to cook chamber opening....

chimney volume = 5% of firebox volume

3. ### bhawkinsSmoke Blower

Great read. I has already found Feldon 's calculator and dimensioned my new box accordingly. I also cut a half moon exchange hole per calculations. I was just trying to find out of it needed to be a certain height inside the cook chamber or does that really matter? Or do you want it to be as low as you can get it?

4. ### daveomakSmoking GuruOTBS MemberSMF Premier Member

Hawkins, Set the cut-out, of the FB/CC opening, as low as you can get it...  I recommend the area under the RF plate to be 1.5 X's the area of the CC/FB opening......That will reduce friction loss of air/heat/smoke flow through the smoker... The opening at the end of the RF plate also the be 1.5 X's the FB/CC opening...

Dave

5. ### bhawkinsSmoke Blower

Thank you Dave. That is what I have been looking for. About the RF plate, does it need to be on a slant away from fire box if you do not plan on a drain? Mine is only 16" dia x 38" long at centerline. The ends are somewhat rounded out. Just thought since it is as small as it is I could just line with foil as a disposable drip pan.

6. ### daveomakSmoking GuruOTBS MemberSMF Premier Member

Aluminum foil on the RF plate, will act as a heat shield keeping the RF plate hot and the food cool....  You need the radiant heat from the RF plate to cook the food....  When the food is done, throw a little water on the RF plate to loosen the burnt on stuff...

Then open the drain you didn't install..( oh my, that was cruel.... sorry)   I think the drain is installed for ease in cleaning.... make the plate level with a dam on the end....  Most folks with RF smokers don't use water.... if you want to use water, a single use baking pan with water in it will do the job just fine.... A small piece of foil under the piece of meat, or an aluminum baking pan to catch the drippings will work...

Dave

7. ### bhawkinsSmoke Blower

Thank you again for your help Dave.I appreciate your patience.