Solar hot water heater mainly consists of three parts: vacuum tubes, which are responsible for absorbing the energy from the sun and transferring it to the water; water storage tank and the structure that supports the equipment.
The operation of solar hot water heater is very simple: the systems are normally installed on the roof of the house, facing south, in such a way that they are exposed to solar radiation all day.
How does water circulate throughout the solar hot water heater system? This is achieved through the effect called "thermosiphon", which causes the temperature difference. That is, the solar hot water heater system operates by natural convection, hot water is lighter than cold water and; therefore, it tends to rise. This is what happens between the evacuated tubes and the storage tank, thereby establishing a natural circulation, without the need for any pumping equipment.