rocket stove without the barrell?

[earthiest]

I am trying to come up with an idea of how to build a rocket stove with out the barrel. perhaps gathering the flue gasses at the top of the heat riser, making a 180 degree turn down the side of heat riser surrounded in insulation and cob then entering the mass bench as normal. Any thoughts or consideration would be great.
thanks daniel

[Donkey]

I have in the past approached it in two different ways..
The rocket stove in my house, I formed the heat riser of castable refractory, built around it with cob (leaving a void between cob body and heat riser) and filled between with pearlite/clay.. at the top of the heat riser I mixed cob of fireclay and hand formed a manifold to guide flue gasses/heat back down to the bench through a firebrick tunnel. Over this manifold I placed a 1/4 inch steel plate and cobbed it down well to seal.
The above method works well, though the different materials have a tendancy to seperate under heat shock and form cracks..

Another method I used for a hot water heater.. I had a local blacksmith weld a steel heat riser in the form of an upside down J, which guides flue gasses/heat back down into the storage medium (water). I then created a cob enclosure, again leaving space to fill with pearlite/clay insulation.

The main thing to remember when not using a barrel, or some other metal/heat dissipating method is that all of the heat created in the stove will be guided into storage. This is great for heating water or some such thing but for heating human habitat, I find that it takes longer to make a space comfortable without that more instant air temperature boost.
Of course, there will be more heat guided into benches and other storage, which means longer term heating per charge.
Somewhere in there a balance is struck based on your particular needs.


There must be some good reason for not wanting the barrel.. ??