Adamiscold wrote:Can you control the burn rate(lowering the BTU output) by controlling the air flow with the Hitzer gravity feed stove?
The hopper does not contrul feed rate. It is basicaly a rectangular box with no bottom in it. It goes from the top of the stove downward to just a little higher than the door bottom. After you get the coal started, you fill the firebox up to the bottom of the door. Then fill the hopper through a trap door in the top. as the coal in the firebox burns the ash settles down and the unburned coal settles down, and the coal in the hopper which is resting on top of the coal in the firebox, also settles down.
After about 12 hours of burning and settling, it is time to shake the grate, everything settles a bit more, and it is time to top off the hopper again. Looks like I could fill the hopper only once per day with outside temps averaging about 30*F.
So to answer you question (finaly), The bi-metalic spring thermostat can be user adjusted for temperature desired, then the thermostat controlls the draft cover wide open, closed or anywhere in between to control the air admitted in the draft hole. And that is the only control of burn rate/heat production. It works very very well at maintaining temperature of the stove and room, for such a simple non electrical automatic control.
I never did pick up the baro. damper. I don't think I will need one, because when it gets windy and my chimney draft increases, the thermostat senses the warmer stove and closes down the air intake to the stove. Being an air tight stove I don't think much heat is being drawn up the chimney from the stove. The magnetic flue thermometer goes up only about 50* when the wind bows hard.