Step 1: Materials
Tank- some kind of pot
Cob- mud and straw mixture
Step 2: Get Your Hands Dirty
Set one heating duct on both sides of the pot
Mold the cob all around the pot and ducts to hold them in place
Mold the cob under the heating ducts and pots
Do not fill in the heating ducts
Build a kind of bowl shaped structure out of the cob large and strong enough to set the pot and ducts on
This area will be where your pellets go and the heat comes from
Put the pot/duct structure on top of the bowl shaped bottom
smooth the sides with more cob so it is all one structure
Step 3: Imagine
This water heater is supposed to function as a more sustainable option to what’s sold. It also empowers the owner to build it suited to their own needs, even with a minimum budget. The fuel for the fire, the use of gravity, and the placement of the ducts all enhance this model and its benefits.
In order for the heater to fulfill its destiny there are a few more things you would have to do. First, the water heater would either its self be located at roof level or just the water catchment system. If just the catchment is located on the roof, then the water would then run through some sort of piping, through the hole in the lid of the heater, and into the tank, from there out the bottom of the tank through piping to various locations in the house. There are pros and cons to both positions. One option to find a happy median was to put the heater at roof level, install a pellet feeder and ignition, and put their controls centrally located somewhere in the house.
The water heater model we built did not have a sufficient tank for daily home use but a water heater could be built with any sized tank in the same fashion this was built. You would also want to experiment with and document the amount of pellets, time it takes to heat the water, the prefered temperature range, and the time the water will stay in that temperature range.