Thomas Michael

 That looks like a good start.  My notes on an 8" J tube says 10 to 12 # of wood with a 45min burn time, with a 30min feed interval, would put you right @ 100K btu.  I sounds like that is very close to what you have just short of the 125Kbtu you need for a good boil on the full 8sqft.  Lookin at your pictures I like the layout, out and back on top of an insulated chanel.  Are you sure your cross section at the top of the riser is large enough to make a unristricted 90° turn? Also did you try running it without those metal baffles? It sounds like you only need a little bit more burn rate to get the heat you need.

Tuning experiments:
1:  Lift the cover over the riser about an inch
1.5:  And/or notch the top of the riser to add flow left and right
2: Increase the opening down into the lower return. 90° turn @ least 10"x8" opening.
3: Add 4' to the top of the chimney, more pull.
4: Bevel the intrance to the chimney, that wall penetration should be at least 9" in diameter with 45° bevel.  Easy way to do this is a 10" x 8" chimney adapter. Or just shape the insulation into a funnel.
5: Raise the chimney penetration off the floor at least 2" (1/4 diameter) will increase flow.

Note: airflow into a hole in a plate comes in from the side of the plate not straight into the pipe.

Fyi: A round hole in a plate only flows about 62% of what a tube of the same diameter flows.  That's why i think you need more cross section at those transitions.  Flares in and out of pipes help flow alot.  Tom

I like lifepo many have life times listed as 3000+ cycles, that means ~10 years if used every day. Twice a week?  it's the last/only battery i'll ever need for that device.

Not mentioned in that article is that there are 2 kinds of lifepo batteries:
1:  Most LiFePO4 batteries have a maximum discharge rate of 1C, which means they can deliver their rated capacity over a period of one hour.  This works good for most storage battery usage.  It is a problem for electric vehicles when they have occasional very high current demand.  
2:  There are lifepo so called starter batteries available now that will do 5C+ these are the kind intended to replace a lead acid starter battery in a gas car.
The nice thing about lifepo is they are chemicly stable.  They do not catch fire and burn your house down.  

lithium ion batteries have a much higher discharge rate and are commonly used for electric tools, lap tops and vehicle batteries.  
I have seen three lithium ion battery fires.  I don't like having even small lithium ion batteries around.  You can not put the fire out and the fumes are toxic but, at least a small battery you can chuck outside.   I will never have a large EV or house battery using lithium ion.  Tom

  I know of a local accident corner, on my old work comute.  They put up  a cement block wall. My thought was that was going to be painful and expensive next time someone runs off the road there.  About 3 months later I drive by and the wall is smashed in. Turns out they had dry stacked it.  Blocks went everywhere and i am sure many where damaged but that wall was nowhere near the killer stop it could have been.  Tom

I was late, my order went in yesterday.  They already have many sold out.  Last year was terrible very little germination but, I did get 1 water melon from the 30 or so seeds. I'm hoping those seeds will do much better the second year.  6 or so plants 1 fruit.  It tasted great so i have high hopes. Tom

I would just plant them in a planter on the porch.  They will get freeze thaw cycles of your weather and you can then trans plant the seedlings in april.  Tom

16 seed packets .25¢ = $4
3 MI Gardner $2 = $6
Rototiller gas = $1
Drip tape = $48.41

Time: about 4 hrs to set it up and an hour a month.  My notes say 8 hrs Total.  Probably closer to 10hrs when I add Oct and harvest.

I see I missed posting the final harvest pix or numbers.
GAMCOD last harvest:
Sweet corn on the cob: 714g
Dry on the cob corn: 142g
Tomato: 8g
Lemon cucumber: 212g
Carrots: 54g

The garden in general did poorly this year.  GAMCOD on dirt without my normal barn bedding fertilizer very poorly.  But I did get another year for my sweet corn grex. This corn is all going to be seed for next year.  I did separate it into early and late batches.

Harvest.
Very little grew in the gamcod bed.  I just harvested the 1st 2 tomato's 45g for both.  Since it looks to freeze Sunday night (in 3 days) I also harvested the 1 cabbage but it is all bug food.  The pumpkin weighs 1288g and the remainder of the cabbage was 73g.  Corn, squash and carrots tomorrow.  There are some green tomatoes left but I expect them to freeze before they turn red.  

Missed the update for aug
Time update

10 July weeding 30min
8 Aug weeding 30min
17 Sept weeding 30min

Finally have a tomato on the vine.  There are some carrots and 1 small head of cabbage and 1 pumpkin.  The flowers have looked good for the last month.  Running out of summer.  The only harvest has been flowers.

Our permies expert was Mike Oehler's his underground greenhouse book is worth a look.
https://permies.com/wiki/23444/Earth-Sheltered-Solar-Greenhouse-Book

Mike is where Paul got the 3 layers of poly earth roof used in the wofati.  From what Ive found on line dry dirt insulates very well.  Using 3 layers of normal construction poly that all slopes away from the building gives a large chance of dry dirt around the building.  Paul has brain-stormed natral waterproofing.  The most likly is a 6" layer of clay.  It would need to be a multi level reduntant system. Somthing like 2" of clay plaster directly on the wall and roof, 12" of sand/dirt on the roof plus walls bermed to 45° and then 6" of clay, plus 18" soil.  I dont think anyone has confirmed it works.  Plastic works and is much easier to spread.  

Researching portland cement the problem is it wicks water.  Your walls would be wet and that lowers the insulation effect. But it is strong even wet so it is the safe answer.  Another safe answer is an 18" thick wall above ground with large roof overhangs.  In zone 4 i don't think it will work, in your zone 7 it should be fine.

I have a been planing an underground greenhouse and ramed earth sounds like the wall I will use.  Stablized with type-K quick lime and protected by a 3 layer plastic earth roof Mike Oehler style.  Everyone says dont bury a ramed earth wall but if Mike can bury pine logs and not rot for 50 years, i dont see why i cant have dry walls with stablized ramed earth.  Plan is two 12'x12' rooms to suport the back wall in the center with an interior wall, flying butress.
I'm @ 43° North and planning on building something like this next summer.  Without glass in the roof it will not have full sun in summer, but I'm gardening outside then.