Fox James wrote:If you rest the core on a concrete floor it will act as a heat sink and stop the fire box and tunnel getting to high temperature.
If you lite a fire inside a concrete box, the heat will be sucked into the concrete and eventually radiate from the outside at a lower temperature but, if you insulate the box the heat will stay inside the box making the inside much hotter so full combustion can take place.
So if you build a rocket stove using a fire brick box, you would need to insulate the back side of the bricks, the fire will first have to heat the bricks but the insulation will hold the heat back and stop it radiating into the air.
Now if you have a concrete floor the fire would have to saturate the whole floor before it could start heating the box to maximum potential.
So on its own, pea gravel wont be able to absorb heat or store heat very efficiently but, if you add sand and cement to the gravel it would become a solid dense mass.
Thanks for the input!
I’m planning to construct the burner from ceramic fiberboard and firebrick with a 5min riser. The cinderblocks are for holding up the stovepipe, the pea gravel will go over top of the pipe and filter down around the whole setup. I’ll def add sand over the gravel to increase density and will probably end up trying to create a cob outer layer to retain the mass instead of using a wooden box.
I think with my stove design I’ll be ok on getting temps up, my big concern is how direct contact between the 35’ mass and the floor will impact heat retention and distribution as a joined mass.
