This is the idea I had to make he most bang for your homesteading buck. If your going to burn wood for one thing might as well use the excess energy for other tings as well. The wound 1" copper pipe goes inside the upper pipe at the top that is shown in diagram. You must use high temp water hose for all supply and return water. the water will heat up very quickly. I have not built this yet, its my next big project. I will have to have my buddy help me with the welding. I believe together we are better no matter what we're doing in life.