posted 9 years ago
If you must build outdoors, can you put the unit next to the house and close to a door? If you can somehow create a vestibule with the RMH and the back door, it would become almost practical to tend, and less wasteful of heat. No matter what, you need to keep the unit close to the house and enclosed in a weathertight shell. I would try making a bell-type enclosure, made of interconnected individual barrel tanks if necessary, with lots of insulation outside of the tank cluster. If the whole thing can be lower than first floor level, that would be an added bonus to easy water circulation.
And of course, the only feasible style of combustion unit would be a batch box; a J-tube would take tending too often to be usable.