Solar Geyser Evacuated Tube System: With this system a series of cylindrical glass tubes are attached to a frame and installed on top of a roof. Inside each tube is a copper rod which extends from the bottom to the top of the tube and then into a manifold. A special chemical formula inside each tube starts to boil between 30 and 40 degrees celsius. This quickly heats up the copper rods in each tube which in turns heats the water which passes through the manifold. The manifold in turn is connected to a geyser (some evacuated tube systems are connected directly to a geyser instead of a manifold).