I know this thread is uber old.. and if I remember right this is the chic who got bullied off the web by all the haters! But her set-up is the ONLY one we can find that really encapsulates everything we'd like to do.. so hoping against hope that someone knows how this system has worked over the years? Or where we can find any more information? I thought everything she did was BRILLIANT.. and what a shame that the meanies and horribles of the world drug her down. *boo*
Anyways, we'd like to do an earthen floor with a RMH in a yurt - including underfloor heating (in the form of either RMH tubes or the standard radiant water tubing). I'd like to stay as natural as possible and the site has loads of small shale/schist rock to work with as the flooring 'fill' so and stones we can use as the foundation (similar to the bottom of a cob build)..
Besides this yurt/RMH example.. the only other one we can really find that's similar is a guy in France who did this: (trying to attach photo to post - hopefully it comes through).. but he put a wooden floor on the top of it.
I've spent hours and hours trying to find examples of this with no luck, so if anyone can point me in the right direction of some info I'd sure appreciate it! Or, even better, if anyone has experience..
There are a few yurt books that talk about 'an amazing yurt' that had earthen floors and underfloor radiant heating from Hot Springs.. which is everyone's favorite.. but I sure can't find any other references or information about it?
Water does condense in the pipes on other RMH systems, but not to the point where it would pool and do damage. Earthen masonry is pretty forgiving up to moisture levels around 13-15%, and cob both absorbs and evaporates water readily.
My gut is that any condensed water gets evaporated out again once the fire dies down. Some amount of cooler, drier air flows through the warm pipes as the fuel load diminishes, especially if you aren't tending the fire super-closely and let it burn out completely before shutting the burn door.
The time when RMH's tend to be really drippy is just after building them, especially if you build it in the fall when the weather is cold and wet. Water comes out everywhere - the cob faces, the pipes, the drainage underneath.
We do try to orient the cleanouts so that water can drain down and out.
Ahh just the question and answer I have been looking for!
Also, thanks to the bit in blue, I have just realised something else that helps keep the exhaust tubes dry . . .
While the rocket is going full blast, carbon, hydrocarbons and hydrogen are all burnt at full tilt but the hydrogen and hydrocarbons, are actually driven off and burnt first being volatile, so when it (or any wood fire) dies down there is a quantity of charcoal still to be burnt, so the last 'combustive activity' is actually dry, so the 'dying breath' of the fire (provided you let the charcoal burn before you stop off the air inlet) is actually to flush the tubes with hot dry exhaust.
Rocket Mass Heater Plans: Annex 6" L-shaped Bench by Ernie and Erica