Batchbox rocketstove half mass + steel + pizza oven

Hi all,

A little while ago I participated in a workshop led by Peter van den Berg in Weesp - The Netherlands.

Now, a few years later, it’s time to build my Batchbox rocketstove. (I first had to build the house around it)
I want to post my design here, to see if anyone sees anything in the drawing that goes wrong, before I start building it.

See attached the Sketchup design, and some overview drawings as PDF.

Design choices:

- The batchbox core I already have, we made that during the workshop. It has a 125mm diameter riser. The rest is based on this.

- The stove has thermal mass (stone), in the bottom part for slow heat. And an oven on top (3mm steel) for fast heat and cooking.

ISA:

Stone bell bottom surface area = 1,69 m2
Steel bell top = 1,44 m2
Oven surface area (in the bell) = 0,84 m2

Total ISA = 3,97m2

- The total internal surface area is 3,97 m2. according to Peters website, the ISA should be maximum 3,7m2 m2 for a 125mm riser. Because the oven is floating in the bell, it creates quite a bit of internal surface area. Do I have to count this, and is it a problem that it will go slightly over the maximum?

As an alternative I was thinking that I could insulate the back of the stove, inside the bell. To reduce the ISA.

- I would love to bake pizzas in the oven, so it would be great if it can reach 420 Celsius ( 788 Fahrenheit). Can it reach those temperatures? The hot air can circulate around the oven.

- The space it will operate in is insulated quite well, but has high ceilings (7 meters). There is an underfloor heating system, powered by a heat pump. But I want to see if we can use that less, by using the rocket stove more.

- The steel parts will all be laser-cut by a company, based on 3mm sheet metal.

Looking forward to hearing your thoughts! Also: feel free to re-use this design.
After its build, I will post the results in this topic too.

Cheers,
Joep