Fire Brick Question

There ae many kinds of fire brick with different densities and chamistries and heat/cold cycle capabilities. Is there a "best" brick that suits the purposes of the fire chamber of a rocket stove mass heater? thanks, Mark.

a fire brick will transfer the heat qucikly across the brick, preventing it from fracturing. I offer that a good brick for RMH would also be insulative

The hotter the fire is and longer it will be in continuous operation will determine what kind of brick you want. Low use, cool fires can get away with a light duty brick having a low alumina content. 30% alumina can do the job. Running it hot for months will need a higher alumina content in the 50% range or higher. The price goes along with the alumina content. You only build it once so I recommend a higher heat and alumina rating. Look for at least a 1500 degree rating.

Thanks, guys. That answers the question and establishes a good standard.