I want to start by saying I have never even heard of permaculture before today and am no way any kind of living example, but I have been perusing this site a bit and there are some interesting ideas here. However, this idea of a rocket mass heater and in particular this one really scares me. I've heated my home with a traditional wood stove since I bought it 3 years ago and from what I can tell the rocket mass heater is both inefficient (no secondary combustion) and unsafe. I say unsafe because of the length of your horizontal chimney as it goes through the floor and the very poor draft that would results, also, I assume the purpose of this length of chimney is to reclaim the heat of the flue gases. This is not a good idea as cooled flue gases will leave creosote deposits and as anyone who has burned wood knows excess creosote buildup can cause a chimney fire. In most homes a chimney fire is a bad thing, but doesn't usually burn the house down. In the case of the rocket mass heater the chimney is running through your floors or you are sitting on it....Yikes! At a minimum I would be disassembling this system every two weeks to clean it out.
Maybe I am missing something and I'm not writing this to turn it into an argument, but I am begging users of this site to stick with the traditional wood stove, hot flue gases are supposed to stay hot for safety not to have the heat re-claimed for radiant heating and the secondary combustion systems offered by all manufacturers now make the burn cleaner than any rocket stove I've seen on this site. I can't definitely say anything about heating efficiency because I've never seen a rocket stove in action or been in a home with one, but I can't see how it would be better than my traditional stove with secondary combustion, and it certainly is nowhere near as safe.
