Question: Have you ever had any experience with a do it yourself type hydronic system added onto a conventional woodburning stove. What is the best piping material to use for the floor and for the stove heat exchanger? Is there any literature on this topic that you are aware of? Answer: I do have a lot of experience with this type of device. Based on my experience, I'd recommend that you rethink the project (read that..don't do it!). There are a number of reasons why a hydronic retrofit to an existing stove may not be a good thing. 1. Safety...Pressure vessels that come in contact with flames are strictly regulated. They are made from special materials and under strict conditions (ASME CODES). Piping and other DIY materials do not meet this standard. 2. Effectiveness..The amount of heat generated from a hydronic vessel depends on the number of square feet of surface area of the heat exchanger that comes in contact with the fire. The boilers I imported from Denmark had 20-50 SQUARE FEET of area surrounding the firebox which was filled with water. A small heat exchanger (2-5 square feet) will produce poor efficiency and minimal heat. 3. Installation...Bringing piping, circulators, electrical controls and pressure relief valves into the living are of a house is not always easy..is the return worth the effort ? It is possible to produce your domestic (bathing/household) hot water from such an arrangement. There are a few companies that make stainless steel probes or jackets designed for this. I've also used copper coils (either bent or with 180 degree turns-silver soldered- to make a serpentine) on the OUTSIDE of a stove...then used controls and a small brass pump to exchange the heated water to my tank in the basement.