A couple questions on the reverse flow theory

Discussion in 'Wood Smokers' started by deskjockey, Sep 4, 2009.

  1. When you have an offset burner, even with the reverse flow system, isnt there still hot and cold spots?

    With the tuning plates in, are there spots that are "smokier" than others?

    Wouldnt a burner box that is behind (as you are standing at the smoker) the smoke chamber, have even heat and smoke throughout the smoker?

    Designing a build right now and wanted to get the expert's opinions [​IMG]
  2. crd26a

    crd26a Newbie

    Here's my .02 and by no means an expert

    We use a Good One Rodeo for our competition team. The unit has a firebox running the entire width of the unit and pushing heat through the baffle into the main chamber. It's a great smoker and can cook pretty evenly across. However, as we burn charcoal in it, you HAVE to try and keep it lit all the way across at the same time. We might get this done 15-20% of the time. This creates different temps side to side and is something we are constantly watching as we cook. In a stick burner it might be a little better, but I would imagine you would still have to have hot coals / fire across the majority of the burn box to keep temps constant across.

    On a reverse flow, to me, the plate in the bottom the air travels under before coming back up with help hold in heat, allowing for quicker recoveries in the smoker, plus a more even distribution of heat. I would imagine the low side right by the firebox would be a little warmer, but as the air would travel in one side, up, and then back to the other, if the stack is coming out mid-level to top, I'd think it would help even it out. If its at the bottom, I'd still be willing to guess its close.

    As I'm looking at what I want for my next smoker, reverse is the most attractive to me, but then again, I change my mind weekly
  3. pignit

    pignit Master of the Pit OTBS Member SMF Premier Member

    My brother and I designed a pig smoker for my Dad last year and I took a really good look at all the different configurations and have learned a lot since the build. We ended up doing a charcoal/stick burner and put the burning grate directly under the cooking trays with a baffle inbetween. I think that regardless of the design your going to get a variation in temp inside the smoker.... from less to alot. My thinking is by creating turbulence inside the smoker you even the ambient temp out more. I have an Oklahoma Joe that I created end to end temps that were less than 3 degrees off by building a false wall on the end with the exhaust and put it at grate level. It cooks very evenly although there is still that one hot spot coming out of the firebox that I'm working on. It isn't enough to bother me for the type of smoking I do with it. The offset in my opinion creates enough turbulence getting the heat from one end to the other and back.... it would keep a pretty even temp throughout. Every design has it's pros and cons.


    You have to look hard to see what we did here... but there is a fire grid on the bottom.... then a baffle in an angle directing the drippings to the center to a trough with a drain in it. Then you have the rotatable cooking baskets. Only used it once and it worked great. Getting ready to fire it up again this next weekend for the annual pig roast. I'll take plenty of pics.
  4. meat hunter

    meat hunter Master of the Pit SMF Premier Member

    Yes, there are still hot and cold spots, but they are greatly diminished compared to the basic design of the firebox on one end the chimney at the other. With a basic design, the heat enters the main chamber, and like heat does, it wants to rise. Thus it travels across the smoker and out the chimney. With the offset, the heat rolls under a steel floor, the heavier the better, and thus cooks by convection so to speak. The heat absorbed by the steel floor radiates up towards the items being smoked, plus, the thicker the steel, within reason, will give you faster recovery times when you open the doors. Combine that with the heat that goes by the plate and back around (reverse) into main chamber, this makes for well rounded heating, but not perfect. You would have the same problems with the design of the firebox behind as you would on the side. Meaning, if you had one chimney on one side of the smoker, the heat would naturally gravitate towards that end, leaving the opposite end cooler. Same thing if the chimney were in the center, the heat would go towards the chimney, thus leaving each end cooler. Knowing the cool and hot spots on any smoker is the real key if you ask me. Just like a professional grill in a steakhouse, they have cold spot and hot spots, and a good cook will know where they are and how to use them. Putting a larger chuck of meat on the hotter area and smaller cuts on the cooler areas can help in getting everything done at the same time to close to it.

    Am I an exert at this? Far from it, but I did stay at a Holiday Inn express last night[​IMG]

    Hope I did not confuse you in anyway, if so, let me know.
    Not to toot my own horn or anything, but here is a link to the one I built this year. http://www.smokingmeatforums.com/for...t=75075&page=5 Also, for some ideas, you may want to check out BBQ Engineers build. An insulated model. Very sweet.
  5. I have been thinking about this for awhile.

    You guys have confirmed what I thought, there will always be hot and cold spots, the idea is to minimize the discrepancy between them.

    The cool thing about discussing this, we can all learn the pros and cons of different set-ups, then decide for ourselves what we would be most comfortable with.

    I love reading the build ups you guys do, really shows the nuts and bolts of the procedure.

    Also shows the creativity each one of us has

    oh yeah meat...was reading your build up, beautiful welds there
  6. meat hunter

    meat hunter Master of the Pit SMF Premier Member

    Hey thanks for the compliment. It took me a while when I first joined here, on what unit I wanted to make. I was set on an electric unit, 100%, because I was unsure of how the old burning stick method worked. Once I learned a bit, I was set on propane, seemed pretty easy, kinda set it and forget it so to speak. And after all that, and asking the same questions over and over till I got it, only then did I decide on going old school and use wood. Glad I did. Yeah its a bit more labor intensive, and it takes up more time and there are allot of variables in the process, but its worth it in the long run, to me anyhow. My neighbor has a smoker, the kind you get at Lowes, your basic kind and has not a clue on how to use it. Loads it up with charcoal, light it and walks away. Basically just grilling his food. He is amazed at how the stuff I make turns out. In fact, just yesterday, he brought me over a few packs of beef ribs to smoke for him, Yeah, to smoke FOR HIM...

    Whoa, I'm going off on a tangent here, back on track. Yes, this place does offer many many ideas and thought, and many many people on here have had a great influence on my decision to go with a stick burner. Make sure you take photos of your build and post them. Others along with myself would sure like to see it as it progresses.
    By the way, where are you at in the U.S.?
  7. jamesb

    jamesb Smoking Fanatic

    I cook on two trailered pits. One is a reverse flow, the other a traditional offset... On the reverse flow, you actually have two hot spots to contend with. One by the firebox (where the plate is still hammered by heat entering) and at the opposite end where the reverse flow plate ends and the heat/smoke etc. rise to return over the food... Then if your plate is not low enough you will be dealing with the radiant heat from that as well.

    Both work well, but I find my reverse flow to require more fuel even though the other offset is a larger pit (8' x 30" on the reverse flow vs. 8' x 44" on the regular offset).
  8. I have had good success with this smoker but I need more capacity.

    Really the only thing that is of a concern is efficiency, I have been thinking of ways to bring down the costs associated with a stick burner.

    If you look into the pricing of the insulation that BBQ engineer used you will see that stuff is major coin.

    Thinking of a barrel inside of a barrel design, to me the design and build parts are the most fun.

    BTW Meat, I'm just outside of Detroit
  9. bigbaldbbq

    bigbaldbbq Smoking Fanatic SMF Premier Member

    Well as somebody that has a smoker that has the firebox in the back.

    I have a 1/4" plate across the bottom.

    Here you can see that the inlet is below the plate.

    The only hotspots that I encounter are directly above the inlet, And I can avoid those with no problem.

    If you look right in the middle you can see the light coming in from the smoke stacks. That is the hot spot.

    I Hope this helps a little.

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