Exhaust stack size

[ndhunter]

I hope Im posting this in the right place. Forgive me if Im not. Im building another custom pellet powered fridge smoker. I have a 6" diesel exhaust stack that im going to make my smoker stack out of. My question is, how long should it be? I know there is probably a science about it somewhere, but I can not seem to locate it. My inside box dimensions are roughly 50"tall x 22"wide x 16"deep. I found a calculator for stick burners, but nothing for pellet powered stuff. Any help is greatly appreciated!!! Thanks Ken

 

[mrh]

Ok here is my experience on this so far.... I just built a smoker out of a food warmer and used a Smoke Daddy pellet hopper in it.. I started out with a 3-1/2" hole in the top center and had a upside down stainless dog dish as a manifold with two 2-1/2"  exhaust tube stacks.....  I also cut in a 2-12" floor register low in the back wall for more air flow.    It worked but couldn't get the temperature down to the 160 degrees that it is supposed to go.  Sooooo we removed the dog dish and re-cut the hole to 6-5/8" ( Biggest hole saw I could find) Then did the dual exhaust again using two 4"  vents.  It will get down to the 160 now,  I have only used it once and it I might even need to choke things down a bit now..... Time will tell.  Still trying to figure this out myself.

Mark

 

[ndhunter]

Thanks mark. Mines going to hold heat pretty damn well. It had 3.5" of a spun mineral wool. I'm gonna go with a 6" diameter stack. Trying to figure out optimum length. I also have a in floor heat register for more air flow. I believe the dimensions are 2.25"X10". I'm striving further 160 to 170 mark as well. Post pics if you can. Thanks ken!

 

[stickyfingers]

I don't think the length matters much, it's more of the diameter. I've seen rigs and businesses extend their stack beyond their roof line.

 

[ndhunter]

You may be correct stickyfingers. Trying to find a happy medium. I'm going to have a nice chunk of change tied up in my smoker and once she's painted all pretty like, I don't wanna put more holes in her lol.