This simplest way to describe how a Solar Hot Water Heating System works is to look at the two most basic parts of the system — the Collector and the Hot Water Storage Tank . As sunlight strikes the solar collector, water inside heats up. If you use an “ active ” system, sunlight heats the roof collector which activates a pump and controller.

The pump moves cool water from the bottom of the water tank to the collector for sun-warming . The heated water circulates from the collector b a ck to the tank.When the water in the tank is wa rmer than the collector water, the controller switches off the pump.

An Integral Collector Storage “ passive ” System (ICS) combines the storage tank and the collector in one unit. Sunlight heats water in the roof-mounted ICS throughout the day.When hot water is used in the home, it is delivered directly from the storage tank and then replaced by solar heated water from the ICS. This system requires no pumps or controls for operation.

In both active and passive systems, a conventional gas or electric water heater provides backup during periods of prolonged cloudy weather or excessive demand. This assures the seamless supply of household hot water.