Placment of dampers in centre feed smoker

[PetesMeat]

Hi Everyone,

Building a centre feed smoker at the moment, I have a build thread going for it, but I have a question which I felt warranted its own topic.

I need to put the air intake slots in the firebox. I am going to go for the rectangular slots with a slide over shutter over it, and a slot on either side of the firebox (I don't want to put a vent in the door). I can use pitcalc to work out the size of the vents, although pitcalc is not really set up for centre feed, I can still use it to get a rough estimation.

So my question is, where to put the vents. I was thinking about this quite a lot. I don't want to put the vents by the side of the fire. I feel the lower the air intakes the better, as it would give a better chimney heat rising effect. I also dont want the fire to be exposed through the vent holes caus I plan on having log storage either side of the firebox and i dont want to start a fire this way! I have a removable ash pan. I could put the vents lower down but I dont want the air being sucked on to suck up ash and take it into the fire.... My gut instinct is to have a two inch gap between the top of the ash pan and the bottom of the basket, and have the vents aligned with that. There will be probably an inch and ab it of clearance around the basket and the ash pan and the walls of the firebox so this should provide enough air flow.

I have done a diagram to show what I mean... What do we think?

https://scontent-a-lhr.xx.fbcdn.net/hph ... 5593_o.jpg

[Gizmo]

You are absolutely correct.

… and ignore my question on the other thread … answered here.

[PetesMeat]

Ah good, glad I had the right idea. Just done some pit calc checking.

I have put a estimated intake size as 12x2inches (its going to be a 6x2 slot on each side). its saying intake count 1.22 - is that just a funny way of saying the intakes are too small? Im assuming I need to tweak to get that number 1 or less.... If its less, im guessing that will just mean the fire might be a bit too enthusiastic when the dampers are all the way open, correct?

Pete.

[Gizmo]

I think that's bad.
It means you need 1.22 of the grate you have.
You need to enlarge them slightly and you'll be fine.

[Puff]

Pete,

My firebox is nearly the same as yours. My opening for the vent is 3x 10 inches on each side and with my ash pan 1" off the bottom of the FB, the vent on each side is 1" above the top of the ash pan and about 3 inches above the bottom of the FB