Firebox to Smokehouse piping question

[SmilinNSmokin]

All, I am planning to build a smokehouse this spring. I am drying roughcut cedar in my shop now. I’ll be running a pipe from the firebox to the smoker. A design similar to atcnick’s and cowlady’s smokehouses. A couple questions for those of you who have made a few smokers and have experience and ingenuity.:

1) Is it best to go with a 10 inch, 8 inch, or 6 inch pipe, and what is the best length (somewhere from 4’ to 10’ I would imagine is best) to run from a firebox to the smokehouse?

I will probably be using single wall pipe, and will encase the pipe in concrete, and have an elbow that comes up in the middle of the smokehouse floor. And I will have a diffuser that is removable (for cleaning), mainly to keep ash and soot from getting on the meat, and for allowing the smoke to evenly flow inside the house.

2). I am unsure about physics, but I will probably angle the pipe at about a 10° angle, sloping up to the smokehouse from the firebox to help with smoke flow. If I use a larger diameter pipe, and if I were to have the ability to put on a removable cap on either or both ends that reduced it down to a 4 inch hole, will the smoke even flow correctly into the smokehouse? I realize the smoke travels faster from the firebox to the smokehouse, and then slows down once in the smokehouse, and then exits through the exit pipe fast again. I just don’t know if the smoke will back up and not flow correctly if I try to reduce it with some sort of cap with a smaller diameter hole in it. I will mainly be smoking pork, beef, lamb, seafood & cheese.

I am still wondering about being able to do both hot smoking and cold smoking in the same smokehouse; hence the idea was to reduce the pipe size when I need to modify air flow and heat intake with a cap, but only for when I want to cold smoke cheese, or bacon. That being said, I could probably just put a smoke tube in the bottom when I’m doing cold smoking, but just trying to plan the design, and I’m probably overthinking things…

 

[mike243]

Well pipe size will depend on how big of a smoke house your building 6-8" would move a lot of heat/smoke, fire size will determine hot/cold smoking, just don't use galvanized pipe for the feed pipe, use black or stainless pipe and good luck.

 

[SmilinNSmokin]

Well pipe size will depend on how big of a smoke house your building 6-8" would move a lot of heat/smoke, fire size will determine hot/cold smoking, just don't use galvanized pipe for the feed pipe, use black or stainless pipe and good luck.

mike243, external dimensions will be 56” x 48”. Inside will be 47” x 41” so a smaller smokehouse. I am leaning toward a 6” or 8” pipe and probable 6’ or 8’ in length. Do you think that’s about right or would you step it up to an 8 inch pipe? Everything else about the firebox in the house I am dialed in with, but just need a little advice on that one aspect of the build.

 

[SmokinEdge]

Biggest question is what type or size of exhaust pipe?
In most cases 6” is sufficient for smoke intake but remember you cannot intake more than you can exhaust. 4-7’ length is most common and 5-10* slope works well but more is fine too if you have the terrain to do that with a hill.

 

[SmilinNSmokin]

Biggest question is what type or size of exhaust pipe?
In most cases 6” is sufficient for smoke intake but remember you cannot intake more than you can exhaust. 4-7’ length is most common and 5-10* slope works well but more is fine too if you have the terrain to do that with a hill.

 

[SmilinNSmokin]

Thank you for your help! I went and bought two 6” single wall Duravent 48” segments at Home Depot, then read your reply. I will run them together. Perhaps cut about a foot or 2 off. It is just regular black non-galvanized stove pipe. Should work out well and I will encase in concrete. Again, really appreciate your help!