Adam : The combustion core Has to be made of Firebricks and then insulated around the whole of the Burn tunnel and the Heat Riser, your 12 by 12 tile could work
as part of a bell in a 6'' system ! A fresh air intake will not automagicly solve all the RMHs problems and will introduce some more. The cross-sectional Area of a 12 X
12 system is 144 sq inches. That
should be the CSA of the Feed Tube, Burn Tunnel and Heat Riser. Counter intuitively the CSA of 10'' round stove pipe is a little more
than 75 square inches, You would need to run Two 10'' twin exhaust pipes 75sq. ft + 75sq. ft = 150 sq. ft just bigger than the 144 sq. feet of your 12X12 Fire brick
combustion core.
While twin exhaust piping is one way to run smaller exhaust pipes, they will never draw equally, other types of
wood stoves can be run with flue dampers, this should
never be attempted with a
rocket mass heater !
A quick back of the envelope stab at sizing the height of the heat riser and the barrel gap shows 2.5 to 3 barrels stacked tall, now we are talking about a dedicated
furnace room built onto your house!
The
Rocket Mass Heater was designed to be a space heater to heat the core of a home built around its Great strengths. In trying to retro-fit a RMH into your existing
house you are ignoring its greatest strengths !
Please go back to 'The Book' and re-read it, the RMH solves two of the major problems of all types of Fossil Fuel Fired Furnaces and most Wood Furnaces, by burn-
ing its fuel cleanly at Super High Temperatures, and then capturing that heat to be redistributed in the two most efficient ways to transfer heat ! Conduction and
Radiation !
You might want to take a look at the Heat Pipes Article at Wikipedia, this was one of the topics of conversation at the innovators gathering at
Wheaton Labs this fall,
you will see and hear more about this in the near future, for the good of the Craft ! BIG AL