Rocket Stove to Heat Water & Heat Room

[jasculley]

Hi All,

(please download attached sketch)

I'm working with the Chicago chapter of Architects, Designers, & Planners for Social Responsibility and we're planning to use a rocket stove in a new straw bale structure that is approximately 140 square feet of interior space. The structure will be serving as the bathroom for a family living off the grid and we were wondering the feasibility of making a rocket stove that heated the space to a comfortable temperature in frigid chicago winters and that also used the top surface area of the heat riser to heat a 55 gallon drum of water that would be used for bathing etc.

Any thoughts on this would be greatly appreciated!

Jenny

[Donkey]

With a little experimentation and de-bugging, your plan may work quite well.

A few thoughts:
I've found that, given appropriate surface area for good conduction, water leaves little heat for other purposes. A good water heater tends to use all the heat.. A good space heater will do the same. Your system may need to be -- somewhat over-sized to do both at the same time.
Start with and eight inch system. Try it, then work your way up.

The two barrel system in your image seems a bit tall. Placing the heavy parts (water) on top may create a tipping hazard. The works will need to be well anchored or re-designed to place the water lower.
Remember that the barrel that you see in the classic rocket stove isn't strictly necessary. It's simply a cheap heat radiator, made from easy to get metal trash. Other configurations can work just as well, or better.

Further food for thought.. I've recent built a version of the following design:

It works well. The tank sits low down, safe from tipping. Also, with BOTH the fire-box and the flue exit below the tank, the system becomes thermally locked. It's impossible (or at least difficult) for the chimney to cycle the heat out of the system once the fire goes out.