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Why are pit fireboxes typically offset? Education needed...

Discussion in 'Wood Smokers' started by black05tj, Jun 6, 2018.

  1. black05tj

    black05tj Newbie

    I've mostly had smaller vertical smokers, currently use an 18.5 WSM (regret not getting the 22.5), but when looking at non-vertical pits I notice nearly every one is an offset firebox style. Why is this?

    I did find one manufacturer that makes a T-style pit with the firebox below. This design seems like it would be more efficient and easier to get a more consistent heat across the pit than when the fire is off to one side.

    I know of tuning plates and such to help equalize temps, but just curious why pits with the firebox below are not as prevalent. Do they tend to overheat the pit too easily? Or is this one of those nostalgia things where "pits have always had the box on the side, so that's how they should be"?

    I imagine there are Pros and cons of both.
  2. I would say it's more of an indirect heat deal. And it does keep your smoker from large flare ups due to fat drippings. Just my 2 pennies
    black05tj likes this.
  3. troutman

    troutman Smoking Fanatic SMF Premier Member

    Yea Pitts & Spitts (guys I bought my pellet cooker from) sells one. They claim its a great alternative, but of course they would say that. It does take up a smaller footprint then a conventional one but I myself don't see the advantage. Perhaps, like a reverse flow cooker, they can channel the smoke and heat better. Other than that, again, I see no advantage.
    black05tj likes this.
  4. daveomak

    daveomak Epic Pitmaster OTBS Member SMF Premier Member

    Offset firebox allows for temperature adjustment and adding fuel EASY ...
    Plinsc and black05tj like this.
  5. black05tj

    black05tj Newbie

    I can see how adding fuel would definitely be easier in an offset vs squatting down below the pit. Good point, for some reason I completely overlooked that!
    Plinsc likes this.
  6. mowin

    mowin Master of the Pit

    Two different styles of offsets. Traditional has the smoke stack on the opposite side of the firebox. Most require tuning plates to keep the side to side temps consistent.

    The reverse flow offset has the smoke stack on the same side of the firebox. There's a plate just above the firebox opening into the cook chamber that blocks the heat and smoke and directs the smoke/heat to the opposite end, then past the meats into the smoke stack. The RF (reverse flow) typically have side to side temps that are very consistent. My RF has temps side to side within 2*.

    The "t" sthls as mentioned above might be more prone to flare-up as the drippings could enter the firebox.
  7. phatbac

    phatbac Master of the Pit

    Just a couple images i pulled from amazingribs



    Hope this helps,
    phatbac (Aaron)
    Burner76 likes this.
  8. black05tj

    black05tj Newbie

    Great info on the RF offsets! Unfortunately, I've not seen one in action. Everyone I know / hang out with has either electric, WSM, or a cheap offset. So I always hear about the temp differences on the offsets and watch them play musical chairs with the meat, moving it around the hot spots. Thus my questions.

    I will be looking into / researching the RF's further.
  9. daveomak

    daveomak Epic Pitmaster OTBS Member SMF Premier Member

  10. black05tj

    black05tj Newbie

    That's a lot of math! lol Thanks for the link.
  11. daveomak

    daveomak Epic Pitmaster OTBS Member SMF Premier Member

    One step at a time.... write down the number... next step ....
  12. papajoe92561

    papajoe92561 Newbie

    thanks for the photo, i have been looking for this very answer. any issues with your lang?
  13. Smokin Okie

    Smokin Okie Fire Starter


    My OC Brazos, with 1/4" steel, gets hotter near the stack than the FB, just the opposite of this pic. Especially, if I have the door wide open and get good air flow. If I have a hot fire, by closing the door or leaving it an inch or two open and reducing the air flow, I can reverse the hot end to resemble this pic .

    I'm debating tuning plates. They reduce air flow but I'd really like to have somewhat even temps.
  14. MeatSkull

    MeatSkull Meat Mopper

    Low and slow is the outcome. If you hit the 40-140 in 4 your good.
  15. bluewhisper

    bluewhisper Master of the Pit OTBS Member

    Without having looked it up, doesn't a reverse flow tuning plate serve the dual purpose of absorbing/re-radiating heat, and deflecting smoke flow? So the harsh heat from the firebox heats the plate, which becomes an oven floor, while the smoke wraps around.

    I just have a cheap offset and for a smoke deflector I use a piece of duct with holes drilled in it. This was my first try, and I learned to drill more holes. The basic idea works pretty well but if there aren't enough holes in the duct then there's a secondary hot spot at the end, which I was trying to avoid in the first place.


    With some more ventilation, this basic setup helps to spread the heat and smoke across the cooking chamber.