Types of Mechanisms in systems Further, based on the mechanism installed, and the process of heating water thus adopted, the solar water heaters are divided in two categories as follows:

Closed Loop System(Heat Exchanger)
In these systems, Heat exchangers are installed to protect the system from hard water obtained from bore wells or from freezing temperatures in the cold regions. Heat exchangers are also being used forvarious other functions, such as:

  • To isolate collectors in case of very high pressure requirements
  • For use with the collector material, when water chemistry is unsuitable
  • It is used when heat of the water is utilized and it is cycled back for reheating

The water being heated in the collector passes through the heat exchanger and returns back to the collector, forming a closed loop.

This type of Solar water heating system used when the original cold water (from the source) contains chemical contents and is therefore hard water. Thermal fluid (Distilled water) is filled through make-up tank to the outer tank shell. In turn, this fluid gets circulated through the solar fins and tubes and goes back into the top of the outer tank. This fluid acts as a heat transfer media and prevents clogging of the copper tubes due to chemical contents in the original water source. The inner tank gets filled with cold water from the original cold water source. Since the inner tank is immersed within the outer tank, the heat gets transferred to the inner tank through the conducted and convection method and the water in the inner tank gets heated up and available for hot water utility.