Thanks for your replies.
I intend to a build batch box or three.
A J-tube can't compete in performance or convenience.
I think
water cooling the feed tube might allow one to burn long lengths of fuel without risking reverse draft, butthat is an idea that is utterly unproven.
I have been looking for affordable castible refractory, going in the direction of homemade mixes,but now that I have found a source of insulating bricks,an all brick build seemd like the easier way.
For a variety of reasons I need to keep the
dragon outside and bring the heat inside. Because of that ,I want to get the most out of every load,and I am not worried about overheating the house.
So I plan for an 8" batch box.
I intend to place it at the rear of my house,just outside my window,and circulate air through the mass, which will be insulated.
Warmed air will be directed into the return air duct of my conventional hvac system,cold air will be drawn from my basement.
Before any of that ,I want to build a much smaller batch box to go in the
chicken coop/greenhouse.
I don't have a lot of room for mass in the coop but I have run corrugated pipes throughout the foundation,and I hope to use them to store heat, sunnyjohn style.
After I get heat to coop and home,there is a shop to be built and heated,a
bread oven,grills,forges,kilns and maybe some other things to be built.
But first things first. I need to parse out which materials I need as I settle on build.