Ultrasun UVR VacRod Solar Hot Water Heaters provide highly effective water heating in small and medium residential applications. They feature a series of glass heat pipes that consist of two sealed concentric glass tubes with a vacuum created in the void between to aid efficient heat transfer. A copper rod is inserted into the inner tube void which projects into a header manifold, the void being filled with water to optimise heat transfer and sealed at its end. The consumption water flows through the manifold and is heated by the projecting copper rod. This water continuously circulates through the storage tank on the thermosyphon principal thus heating the tank contents. The process is extremely effective and has the benefits of being suitable for lightly pressurized systems and also can be used with mineralized water. Particular features of the systems are:-