Hey Danny thanks for the reply. I know the pictures aren't helpful and some of the stuff you're seeing is the smoker being used as a shelf. It's my old mans smoker that we use for processing our families deer meat and I'm trying to make it better. I live 2 hours from him, so I'll take more pictures next weekend (Nov 16) when I go back for opening day rifle deer season.
I'll try to answer some of your questions, but I must say I'm embarrassed that I don't know all that much about smokers.
Here is a picture of our burner that we hook up to a propane tank. Each burner puts out about 15,000 BTUs I believe.
The smoker is stored inside the building you see it in, but when we use it we put it in the driveway to our shed so we do get some airflow. However, I think the only vents that are currently in it are two 2-3" holes at the bottom of each side of the smoker and they are the same level as the burner, which actually causes the flames to go out sometimes as well. I'll make sure to take plenty of good pictures for you as I know that I'm just typing from a visual of what the smoker is at home.
As for meat, we always put the entire batch on all at once and then start the cooking process. We open the door too frequently, because we get nervous that the propane burner goes out (which one of the three does from time to time) and the way the inside looks, our meat cooks way to uneven when using racks. When we hang summer sausage or ring bologna from hooks at the top we typically don't have the uneven problem.
I believe the stack at the back of the smoker is probably 3-4" and it currently doesn't have a damper. Like I said before, it's embarrassing not knowing this stuff. We fell into this SS refrigerator for free and my old man gutted it, put a vent out the back and cut a hole in the side for the propane hose to fit through and air flow. It worked awesome when just him and I used it for our deer because we had nothing but time and we're just excited to have a new toy and we didn't know any better. Now that the family loves our product, we do 12-15 deer a year for uncles and cousins. The cooking time takes forever and it's been getting stressful and too the point where I no it's time to make the smoker top notch! :)
Ok I'm done rambling. Thanks so much!