You know me, I would be a shade tree mechanic......... I would think about dropping Dave a /PM beccause as you increase your stack length you will change your CC draft. basically as best I understand from Dave, the longer the stack it equates to basically increasing the flow just like increasing the stack diameter. I don't know if that would be good or bad in your case. Guessing bad bacuse as well seasoned as your pit appears, you'd probably not enjoy becoming re-aquainted with its cooking charactistics again. Also any PI, or turn, 90's or 45's also would have to be figured in.
Campsmoke , I was think a 'fart fan' would work ....The stack will be about 6" from the roof ; enough to keep to heat from scortching anything .
But I.m wondering if that would help the drafting , or is more exhaust pipe neededlenghthing my pipe above the roofMy objective is to reduce smoke in the 'Bana' and still have good draft.
Thanks . . .
But you'll have to have an idea what you'll do before he could do much more than educate, he'll need what you would like to use to figure out your flow.
For instance, say 3 ft. extension may equate to increasing the stack diameter by one nominal size, but if you count the friction loss from 2 offseting 90's it may well equate to back to no change. But Dave is the genius at numbers. I know, I know, we didn't used to have to think about stuff like that, you just would re-learn the dynamics of the pit and complain about how it used to be. LOL..... been there done that.
But Dave could much better explain than me.
I do use those steel scrouring pads on top of each vent pipe on the house to ensure the dirt daubbers and wasps don't get in and start making them selves home. Friend uses panty hose, on the vents silly, but the heat might deter that idea.
I'll keep thinkin on it. Remember to drop Dave a /PM he's forgot more than most of us will ever know.