My bus is my home. It gets to 0 fahrenheit here. I want a rocket stove as backup to my propane heater. It might need to be more like a rmh though or a hybrid. I'm thinking fire brick and adobe with metal chimney. I'm hoping to stick to j type rmh principles. Any advice appreciated.
Edit: just delete nobody will answer this bs.
If not you could put the burn chamber out side and thread the riser through the bus to exit at the top with a small bell stratification chamber to extract the heat.
Do you have pictures and dimensions of the bus?
If the bus is guttable, then one could even imagine a Kang underfloor heater so you only lose vertical height and not horizontal space. And then cook outside in a tent with the waste heat heating your living space.