Type of technology is called Thermodynamic. This system will product hot water all year round and even during the night when there is no Sun Light. The Principle of the system is it takes advantage of the physical properties of a liquid refrigerant which, when changing state from liquid to gas and gas to liquid. It will extract energy from the environment and transfer that energy into heat. Are ideal for large houses, blocks, hostels, hotels, restaurants and factories (companies). Also proved to be excellent for heating swimming pool water!