Another grilling question- temperature control

[TweetyBird]

Ok, I ran a test chicken today . Here's my question. I had certain temperature range I wanted to keep the chicken at - like 270-225. I learned from America's Test Kitchen, to alway count your coals for a specific grill to generate a specified heat, and it makes temperature control much easier. Makes sense - no problems so far. So I know how many coals will take me to 275, how long they will last till it gets to about 225, and how many I must add to get back to 275. Now here's the question.

It only works if I add hot coals (i.e., fire em up in a little stove or something). If I simply add the same amount of coals to the fire box, it doesn't go up to 275. It maybe goes up to 250. But if I fire the coals up in a stove and add them, I go back to 275 with no problem. Whats going on here?  There has to be some law of thermal dynamics  (or whatever) that makes this happen. Can anyone explain it to me?

[rpm]

The hot coals are already burning, emitting heat. Adding cold coals draws heat from the burning coals to ignite. It's like adding cold water to boiling water.

I never got that technical. I build a fire, throw on chicken, sprinkle with beer if it starts to burn.

[Ripsnort]

Circle of coals, almost white hot. Chicken in the middle, lots of Johnny's seasoning salt, cover, vent 1/2 way, cook 1.5 hours.  Wear eye protection when you cut the breast off the bone due to squirting juices.

Temperature measurement is more important when cooking Prime Rib on the grill.

[TweetyBird]

>>The hot coals are already burning, emitting heat. Adding cold coals draws heat from the burning coals to ignite. It's like adding cold water to boiling water.
<<

That makes sense. Yea, whatever energy started the hot coals doesn't exist if just adding the coals to the fire box. The energy used to start the coals just added cold to the firebox is taken from the heat of the fire box. Now it makes sense - thank you