This was an interesting book. However, there was a lot of information about large scale compost water heaters and I was looking for more information on heating a small greenhouse with compost.
Then I used a very basic design and built my compost water heater. It did not heat up at all. I used chopped up leaves and cow manure. I was very disappointed. Then I got analytical. Did the book give any real hard numbers about how much a small compost water heater would cost, materials and labor. I have over $600 in mine. Then I went on YouTube and could not find any real world dollar numbers on any of the compost water heaters.
The book is inspirational, and that's the problem. It gets you excited about heating water cheaply. I could have heated the greenhouse all winter and maybe next winter with propane for the time and energy and research and money that I put into this failed project. Really wish this project would have worked...but it didn't. We need real numbers!! Also, why didn't my compost heat up??? I layered the materials and watered the layers. I also put sticks in the layers for oxygen. Why, why, why didn't this compost heat up???? Very disappointed. Do not go into this project blindly. And make sure you count your time in the cost, because it takes a lot of time to gather materials and then put a compost water heater together.
Good luck with your project.

Good read.

This was purchased for son who lives in a1865 farm house that he has renovated, but with consideration of the age of the house, and era appropriate. He trys, also, live "green" as much as possible. He was delighted with this book and also the Bio-Integrated Farm.

vey interesting, and an idea worthy of further investigation.

fun reading, with good examples