Dual Energy

In a forced circulation system the collectors go on the roof and the cylinder indoors, usually in the plant room. A pump, controlled by a unit that compares temperatures, sends the collector fluid to the cylinder's heat exchanger whenever the sun can provide heat.

Dual-energy systems have a cylinder with one heat exchanger, for the collectors, and the option of an electric immersion heater for cloudy days. They suit buildings with no central heating to connect, or where it is not needed for hot water. They come with a red or blue cylinder of 150 to 1000 litres (blue in 150, 200, 300 and 1000 litres) and a pre-assembled kit.