Duraco Solar Heater Normal Pressure 300L

The solar collector consists of open vacuum tubes which absorb the solar energy from the sun rays, converting it into heat energy. When in contact with the cold water the energy produced heats up the water inside the vacuum tubes.

As the water inside the tubes heats up, its density decreases and the hot water rises into the hot water storage tank. Due to its greater density, the cold water in the tank will flow down into the tube.
The whole process is repeated and the hot water will circulate continuously until its temperature inside the hot water tank reaches that of the water inside the vacuum tube.
This natural phenomenon is known as thermosiphon process

The unit is filled with cold water through an assistant tank to top up water loss through evaporation.