Ok all you engineers, I need your help

[fourthwind]

Tomorrow my partner and I finally start my competition RF trailer build.  We have most of the planning done, but I am not sure the "smoker calculator" is working for this application.   This is about a 300 gallon build, and I am going to use two five inch exhaust stacks.  One of them is going to have it's flow divertable through a warming box that will be around another 120 gallons.  32 by 36 by 26 are the dimensions of the warming box.   The calculator say's I need 2 stacks that are about 15 inches in length.  How should I compensate for the fact that the smoke from one of the stacks may be diverted through the hot box?  Thinking I should put some vents on top of the box as well.  What are your thoughts? 

 

[bbally]

Need to see more of the planned warming box?  Are you heating it indirect with an exchanger or are you letting the smoke go into it?

It the latter you want to rethink that.  Creosote.

 

[fourthwind]

I was planning on active smoke going through the box.   This is what I am seeing in my head.   Curious as to why I would get creosote this way? 

 

[bbally]

I was planning on active smoke going through the box.   This is what I am seeing in my head.   Curious as to why I would get creosote this way? 

 IS the black box under the red box your fire box?

Is so no problem, what you drew up is not what I was seeing in my head when I read the description.

 

[fourthwind]

Yes the black is the firebox and main cook chamber.  I will get some heat transfer from the firebox itself, but there is nothing more than radiant heat there.  The small angular lines represent butterfly valves.   There will be two five inch stacks eventhough there is only one depicted.  My goal is to divert smoke and heat from the cook chamber through the warming box.  My concern is how this will affect the draft and airflow of the overall unit, and is there something I can do with the stack lengths to compensate.  Just as a clarification, the second stack will be straight out of the main cook chamber.  Not attached to the warming box.  It will have a butterfly valve for controlling back pressure only.