I don't think anyone would disagree with the information in your video. The difficulty is we only have the materials we have, and we want to achieve the highest temperatures possible. I suspect the
RMH burn tube temperature (and other types) is much higher than the measured outlet temperature.
If you put a load of
wood on and burn relatively slowly (low heat), you don't get a large output temperature. If you put a small amount of wood on and burn fast and hot (high temp but still low heat), you still don't get a high output temperature even though the combustion took place at a high temperature. The other point is the chemical reactions don't all occur at once like flicking a switch, even for one reaction say like CO to
CO2. Some happen quickly and some take longer, so you need to have a long
enough flame path. CO measurements for RMHs are pretty low, and as a comparison, from pressure jet oil burners are very low (maybe only 20ppm) and this is inside a boiler whose output temperature from the combustion chamber and first heat exchanger is is less than 200ºC. For these burners, all the combustion has occurred well within a foot of the nozzle.
Ceramic boards which are good insulators, like are used in kilns, would allow very high temperatures, but in the end even those would need replacing. This is what maintenance is all about.
