A basic homemade solar panel for heating water requires three things – a glass covered wooden box, installation for a manifold of copper water pipes inside the box, and plumbing for connecting the hot box to a storage container.
Do-it-yourself Water Heater
The first step is to make a collection box. Ideally, it would be cheaper to use old aluminum awning-type glass windows to construct the homemade solar panel. The lightweight aluminum units are easy to install and simpler to replace from standard sources of supply if broken. These panels are then supported at the sides and back by wood.
The only expensive item in a homemade solar panel is copper. It is the best conducting medium and efficient in containing and releasing heat. Cutting corners, and using any other metal would not serve the purpose. To build the manifold, take couple of, say three to four twenty-feet lengths of three-quarter inch copper pipes (if the box size is about 34 inch by 90 inch). Half inch copper pipes could be cheaper but smaller diameter lines are not good enough for hot water to rise. There will also be a need for a twelve gauge copper sheet which will absorb the heat of the sun rays inside the box. The copper pipes have to be welded together to construct the pipe manifold. The structure could have four bars inside a frame. The interior pipe section has to be welded to the top and bottom pipe lines by using T’s. This entire structure is put into the box of 34 by 90 inch which has the glass fitted on top and the copper sheet below the copper pipes. The entire frame’s bottom is to be covered with a piece of pegboard masonite and two sheets of heat holding Styrofoam insulation.
Before commissioning the homemade solar panel, you need to check for leaks in the manifold. This can be done by allowing water to go through the pipes, and allowing it to by under pressure all night as a test for leaks. The last step would be to paint the collection sheet and the manifold flat black, use a protective oil-based paint on the exposed wooden frames. Set the water heater at an angle of 45 degrees. The last job on the homemade solar panel would be to insulate the water lines with cotton wool from the storage tank to the tap or shower. This will keep the water warm in the pipes when not in use.