Process of firebox design questions


As a builder of rocket style mass heaters the firebox design work has thus far been completed by Peter van den Berg for me. How do you go about designing a firebox in a “traditional” masonry heater?

I’ve looked at various literature from the MHA including their published stove designs and aside from references to the Austrian heater calculator I haven’t found anything specific about the process. I’m aware of the kilowatt per hour calculations to arrive at a kilogram per hour firebox sizing but how does that translate to the other variables such as flue size and air intake?

While we are on the subject what is your current firebox style, meaning floor grates or no secondary air through wall channels etc?

thanks for sharing your knowledge!