DIY Solar Thermal Water Heater: Free Hot Water For Life This project is super simple and uses readily available materials, its the kind of things that could easily be scaled up to meet lots of hot water needs. If you love hot water like me, this is a pro
black painted cardboard for solar window heater. This simple device a traditional window & turnd it into a simple sun powered heater. Materials: Large piece of corrugated cardboard, Black paint, Paintbrush, Knife or scissors.