I like insulated Fire Boxes. I don't own one but got to cook on a cpl and I'm a Fan.
I'd LOVE to have a fully insulated Offset, FB AND Cook Chamber. Cabinet style cook chamber double wall insulated........:heh: I wonder if Paul n Tyler would build one? 48-60" 3 Grate Cook Chamber on the skinny trailer, no warmer of course............Camo Paint Job........ :mrgreen:
There is one Brand that's fully insulated - pipe inside of pipe with insulation but you don't see much of them on Interweb.....
But they say:
"AT 250 F, the thermal conductivity of steel is around 30 BTU/h*ft*F and for mineral wool is 0.304 BTU/h*ft*F. It is easy to see that steel is one hundred times a better heat conductor than insulation.
Below is a table that compares the rate of heat loss per hour through a 3/8" thick steel wall vs. an insulated steel wall (both one foot square) at different outside temperatures.
HEAT LOSS
Outside...............Smoker................... 3/8" thick............Double wall
temperature....... temperature.............. Single wall..........Insulated
100 ,,,,,,,,,,,,,,250,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 144,600 BTU,,,,,,,,,545 BTU
80,,,,,,,,,,,,,,,,250,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 163,200 BTU,,,,,,,,,618 BTU
60,,,,,,,,,,,,,,,,250,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 182,400 BTU,,,,,,,,,690 BTU
As you can see, the heat loss difference between an insulated and non-insulated wall is about 264 times.
It is so vast that that the steel thickness is not really relevant."