Sundra 5-16 solar hot water system

A self-contained heating circuit transports the heat from the collector to the in-house hot-water storage tank (approx.300L). There the heat is passed on to the in-house hot-water storage tank by a heat exchanger and the water for domestic use is heated. When the heat supplied by the collector is not sufficient to attain the desired temperature, a conventional heating system takes over and completes the heating process. An electronic control unit (different-temperature regulator) constantly checks whether the temperature at the collector opening is greater than the temperature in the inhouse hot-water storage tank. If this is the case, the control unit switches on the heating circuit.

Source: Sundra SEIDO5 series Heat Pipe Vacuum Tube Solar Collector