Using compost alone, Jean was able to heat water to 71C+. He used this water for washing, cooking and heating his home. His system was able to heat water at a rate of 4 L per minute.
Thinking of Building Your Own?
Creating a compost-based water heater is excellent weekend project. The only things you really need are compostable material, an area to devote to your compost pile, and lots of polyethylene tubing.
One of the most important things to remember when creating your own compost water heater is to compress the compost pile very well. Since anaerobic bacteria are responsible for heating the pile, the more compressed your compost is, the better your water heater will work.
Another thing that some people have done successfully is create two small piles with tubing coiled in each of them. In areas where space is limited, this may be a good alternative that will still heat water practically as well as a single large pile. Truly, the key is to use lots of tubing and coil it throughout the compost pile – as long as you do that, you should have no issues heating up your water to 70C or better.
As previously mentioned, you could also consider using a compost water heater as a way to preheat water entering your hot water tank. This is often easier than implementing a standalone compost heater and it will save significant amounts of energy typically used to heat groundwater in your hot water tank.
Other people have also used compost water heaters in conjunction with various solar water heating techniques. Although a compost water heater is a very effective solution by itself, the power of the sun makes it an even more reliable option.
And something for the forestry folk; http://permaculturenews.org/2011/12/15/the-jean-pain-way/
In the book Another Kind of Garden, the methods of Jean Pain are revealed. He spent his entire short-lived life studying brush land and forest protection, specifically fire prevention, alongside his wife Ida. These studies led to an enormous amount of practical knowledge for composting, heating water, as well as harvesting methane, all of which are by-products of maintaining a forest or brush land with fire prevention techniques. While this knowledge is applicable in many instances, it is worth remembering that the root of all of this knowledge lies in forest preservation..