The picture shown is a solar water heater I built using scrap materials around my yard. (I was told by the village office I needed to clean up) Other then some scrap 3/4" copper tubing no money was spent to build this unit. The solar collector has been used in my house, which is located in a northern climate, to heat our domestic hot water for three years. I decided to place it on the roof of the house and use a 75 watt circulating pump instead of using convection so it would not be broken by the many children I have playing in the yard. The collector box is an old wooden pain window. I insulated the back with pieces of styrofoam and covered it with lumber wrap.