When water temperature below 80ºC is required flat plate collectors are commonly used. A flat-plate collector is an insulated, weatherproofed box containing a dark absorber plate connected to an array of tubes and is covered by a transparent or translucent cover. A collector is typically 1m wide, 2m long and 8cm in depth. The absorber plate gathers the sun’s heat energy, which in turn warms the water (or antifreeze solution) that flows through an array of tubes. Once heated, the liquid is pumped or naturally flows through the tubes to the storage tank. The heated liquid warms the cooler water in the storage tank directly or through a heat exchanger.