On the 25th and 26th of October we successfully ran a rocket stove mass heater workshop. Approximately 10 people attended and in the 2 days we managed to build a stove for cooking that can also heat our communal kitchen space.
The draw and heating efficiency of the stove is functioning really well. Cooking wise we are still tweaking it to work faster. The stove is able to boil a kettle alright when we build a good fire, but we would like to try to speed up the process so that it is more user-friendly for ‘instant’ cooking. The following will describe what changes we are making to the stove so that the people who attended the workshop can follow its development.
First of all, the whole system is a 6 inch system, which means that the duct and pipe work is all approximately 6 inches in diameter from feed tube to exit. The materials we had at hand determined this size, which probably could have benefitted from having been a 7 or 8 inch system, really. However, at this point, to speed up the heating of the barrel hot plate, we have shortened the burn tunnel (now approximately 1/3 of the heat riser height) and widened the feed tube a little bit so that less heat is lost in the burn tunnel and we can build a bigger fire. We have also insulated the burn tunnel with the leftover vermiculite (mixed with clay so that it can be shaped and sticks to the brick work without being in a container).
Hopefully this will lead to a quicker cooking temperature above the heat riser. For the winter, there is no doubt, having the stove lit in a well insulated kitchen (which it isn’t at this point) the stove will be really hot or warm and ready to fire a kettle without having to heat up the brick work first, and will create a snug refuge for us throughout the day due to its thermal battery.
The old victorian bricks have cracked a few places but they still hold up. If you are planning to install a lasting rocket, do invest in the more expensive fire bricks, especially for over the burn tunnel. If you draw up your design first you will know how many bricks are required and you wont spend more money than you need.
The integrated hot water pot has at this point provided hot water, though not boiling. It is fine for dishwashing and seems to be worth the effort.
Stay posted for more rocketing news!