Batch box autofeed or J-Tube autofeed

[isaacws]

Hi all,
I have been reading a lot on the forums here and I think I am about ready to build my first stove. I am going to be making an outdoor wood boiler for heating my hydronic floor.
My plan for the boiler portion is to modify a gas hot water tank to have multiple flues going through the center. It currently has only one 3" flue and I would like to have an 8" heat riser so I am planning on matching at least the cross section of the heat riser by adding more flues.
For heating a large mass like the floor in my house, I am currently using a 80k btu gas boiler and it runs for several hours each morning. Ideally I would like to light the stove before going to bed and wake up to a toasty house!
Here is my question. I have been contemplating an auto feeding stove like Geo Shoonmaker www.youtube.com/watch?v=LndbgAuYMC8 but I love the batchbox stoves that Peter has been making. I am wondering if anyone has tried autofeeding for a batchbox stove. Maybe a side load system where new wood can roll down into the box or would this mess up the air flow?
If I go with a standard J, what mods besides a tripwire and pchannel should I do? Round riser vs square? I am planning on making the core and riser out of pure fireclay (cardboard tube or wood mold) and then surrounding with pearlite concrete.
Thanks!
Isaac.S

[Dan (Upstate NY, USA)]

Have you made a working "normal" J-tube rocket stove yet? I's start there. Gotta crawl before you walk, or run...

[doggy1969bc]

first of all you need to caculate the amount of btu's you need then how much your system can take in an hour (or more specific ant one moment the max ) then take in acaunt that a kilo/1/2 pound of wood gives a sertain amount of heat and than you can begin to calculate the stove you want