@galenkp sent me here too. I'm a big fan of the rocket stove concept, but I've never been around a set up near as big as yours. The two I've been around were essentially room heaters (cabin situations).
I love the noise, that gentle suck of air. Pretty pleasant and efficient use of fuel...
My first experimental builds were room heater sized, using 5 gal. and then 15 gal. metal containers and having just a 4" burn chamber and riser. I would say 4" is the minimum size you would want for room heating, smaller ones are still good for cooking outdoors.
I've seen some builds online that use an 8" burn chamber and riser, and at that level things start cooking on a more industrial scale. I'm roughing together an idea for a build this size that also heats water and makes steam for running a generator. That project feels like a pipe dream at this point, but just 3 years ago, the build I'm working on now felt the same way.
If you want more information and can't wait for me to post about it, head over to Permies.com. They have the best collection of free rocket stove info I've seen anywhere, as well as a treasure trove of other useful low-cost high-efficiency living solutions.