Positioning and size of charcoal grate in offset smoker?

[ThinBlueChaser]

Imagine a pretty standard direct flow smoker with an offset firebox. Cook chamber 48” length, firebox 24” length, and the whole pit 24” round pipe.

The door of the firebox has a standard butterfly style damper like you see on a horizon or yoder.

The pit is built, and the last piece is the charcoal grate. I want to maximise the pits ability to get a clean burn in the firebox and want to make sure the charcoal grate is positioned to help get the best cleanest fire.

How high off the floor of the pit should the charcoal grate sit to allow air to come in under the grate even when ash has started to accumulate under the grate during a cook?

Should the height of the charcoal grate be set so that the grate sits at an even height between the top and bottom hole of the butterfly damper?

 

[sawhorseray]

I know on my SQ36 that grate is raised about 2" off the bottom of the firebox, but I have slide vents that are on the bottom of the firebox on the side. The ashes fall thru and are easy to clean out by pulling the steel drawer, a nice feature. RAY

 

[Chasdev]

If you look at Franklin's smokers, he has no grates in the fireboxes and runs with the vents wide open at both ends.
In his backyard brisket smoker (shown in his videos) he's cut the splits down to mini-splits around 10 inches by four inches and he stands them up rather than laying them in a pile.
You want a gentle flames slowly climbing up the sticks creating clear blue smoke, not a raging fire.
The plan is to slowly create a modest coal base and not a large pile of coals.
Burning wood (flames) creates the smoke (flavor) but coals create most of the heat.
Too many coals at one time can equal too hot so controlling the burn rate of the sticks is key.