Ray, the NYC build was outdoor, so we looked at it like a fire pit. As for installing a RMH in a home, there are a few regulatory agencies to consider in any install. Local building codes, state solid fuel device regulation, etc. Local codes are one thing, state regs are another. Depending on how you classify your heater and where you live, you might be able to pass both or none. My money is on none. As for someone getting one to "meet code", I have serious doubts that there are any legal installs in Oregon, and I know for a fact that there are none in Washington. Meeting local code is only a small part of the process, the bigger one is state regs. Here's an interesting excerpt from Oregon law:
http://www.oregonlaws.org/ors/468A.465I've been a long way down this road in the last year, and while there is a clear path to getting through this maze, it's going to take a mountain of money to get there.
Now, all that said, there are some states where "masonry heaters" are exempt from a whole lot of the regulations, so in some places it's entirely possible to have a legal install right now, I believe.
I love the soapstone idea! I wish I had access to that stuff, I bet it will work great.
Passive cooling with Earth Tubes is nothing new, and is done all the time in buried homes and even in modern passive house design, as far as I know. If you search around, you'll find all sorts of resources for ideas. Most involve long, buried runs of plastic drain pipe plumbed to cool, shady locations on end and inside the home or the home's mass on the other, with careful attention to slope and elevation, among other things. Lots of details out there, but yeah, I think it would work great. I have zero cooling needs here so it's not something I've put much thought into, but yeah, it seems fun!
http://www.campmackinaw.com/earth_tube_ ... eating.htm