What is the hottest part of a wood fire burning small sticks and with a layer of hot coals on the ashes?

Question

I need to heat a copper pipe as hot as possible and need to arrange it to run through the fire at the best level. Some say one should blow in more air in the upper part of the flame, others think the hottest part is just above the embers.

Answer 1

it is my understanding that the coals or embers are the hottest part of a wood/embers fire. For example old blacksmith technology for making swords was to put the iron rod directly in the embers until glowing hot, to remove the rod, pound and shape, cool rapidly then repeat the steps all over again.

Answer 2

You should blow the air into/under the embers. Make sure whatever you have running through the copper pipe can transport enough of the heat away so you don't melt the copper.