A standard question question is "Direct or indirect?" Is the food cooking behind a shield, or exposed to the glow of burning lump? And why, if you have been cooking on a gasser that produces a bazillion BTUs of heat, food cooked direct on an Egg ends up toast.
The simple answer is IR from the glowing coals is delivering a lot more energy to the food than the air swirling up from the heat source.
So how much?
I did a few small tests.
I fired up an Egg, and settled the dome temperature in at 250. I placed an old blackened pie pan on a raised grid with just shy of 2 C of cold tap water in it.
Direct, 30 minutes later, the water temp was 176 F, via a Thermopen reading.
Then I placed a bigger pie pan on the lower grill, and let the temp stabilize.
Indirect, 30 minutes later, a fresh batch of water was 150. I tried some variations. I put 1/2" of sand in the pan. 30 minutes later, the water was 153. I put a platesetter in, and waited (and waited) for the dome to return to 250. The pan water at 30 min. was 152. The platesetter was 350+.
But an open pan of water must be losing lots of heat to evaporation. So I substituted room temperature canola oil.
After 30 minutes, direct, dome 250, the oil was 260! Got a fat cap down? It will be rendering very well direct.
I took the pan out, and waited till the oil was down to 120. I didn't have all day. With the same large pie pan as the heat blocker, 30 minutes brought the warm oil up to 210.
Considering that meat is mostly water, and meat good for BBQ has lots of fat, the outside of anything cooked raised direct will end up someplace between 180 and 260 in 30 minutes.
That lump glow is hot. :evil: