Solar collector receives solar radiation, heats the thermal media (water or antifreeze fluid), and transfers the heat to the water in the storage tank from where the hot water is available for use. Thermosiphon is a method of passive heat transfer by natural convection.

Solar water heaters that are based on natural convection method are called thermosiphon solar water heaters.

There are various types of thermosiphon solar water heaters available such as direct, indirect, pressurized, and non-pressurized types. Depending on the requirements and suitability, proper type of equipment must be used for reliability and efficient tapping.

Generally, storage tanks and collectors are integrated on a single frame. However, solar collectors and tanks can be separately installed with condition, that the tanks must always be at a higher level from the solar collector, with no sag/bend to the interconnecting pipe between them.

As the thermosiphon solar water heater does not require a pump and many interconnecting pipelines, the system has minimal maintenance and operation cost that considered as advantages of the thermosiphon system.

Capacities start from 150 litres to 300 Litres. Smaller sized systems can be cascaded for large hot water requirements.