Batch Box Rocket Mass Heater!!!!

I’ve been obsessing about rocket mass heaters for over a year now, and now, at last, a large one has materialised in my living-room!!

It’s been quite a journey, a lot of new ideas in my head and a transformation of my understanding of fire….

After looking at many designs and playing with j-tubes and hollow concrete blocks outside, I settled on building a batchbox, following as closely as I could the design on Peter van der Berg’s website: http://batchrocket.eu. This is a highly developed open-source design and on it’s accompanying website, the grand master of rocket mass heaters offers free downloads of Sketchup models of all his designs. I was also greatly helped by the kind souls on the forums of permies and donkey, where technical answers and hand-holding through the process are graciously offered.

During the process, I had a dream that Peter van der Berg came to my house and lit the stove for me and it cracked in half. It was anxious time. But now, it’s rocketin away behind me as I write. Still not raging as it’s not dry yet, but the mass it pretty warm and so is my house!

Design……I scaled Peter’s design to a 175mm system and found the best layout on Sketchup using the local refractory brick. I ordered some rather expensive fibre ceramic boards.

Then I built the lower part of block, got a German friend who had made her masonry heater of similar stuff to show us how to make and use clay mortar and built the core!…The rise is brick low down and then fibreboard only from the top of the firebox up.

And built the bell. The local steel guy in the village made me the floor channel and I used a cast iron manhole cover on t

Look at this lovely channel:

And I lit the lovely lump using the well worn plans!!!!

and it’s all working for now ….more later!

Just finished the door and latch:

I was using it for a few days without the primary air hole, just adjusting by using the door’s opening. In case anyone is thinking of this as a solution…it’s not! With the hole in the spot Mr. van de Berg decided it should go, it works very very well.