Abstract: A solar thermal water heating system including a solar collector unit, first and second heat exchangers, and a drain back tank, ordered respectively in vertically descending relation. The solar energy collector comprises a plurality of heat absorbing modules formed by deforming two plates into intimate contact with parallel metallic pipes disposed intermediate the plates. The uppermost surface of the pair of plates is provided with a black body coating to emit infrared radiation when sunlight is incident thereon. A glazing is provided over such black body surface to freely transmit incident light to the black body surface but to reflect infrared heat energy emitted by the black body surface. A pump for pumping fluid from the drain back tank to the solar collector unit is positioned horizontally adjacent the drain back tank. The first heat exchanger is vertically disposed within the water storage tank for conducting heat to potable water within the storage tank.

Abstract: A solar energy collector comprising a plurality of heat absorbing modules formed by deforming two plates into intimate contact with parallel metallic pipes disposed intermediate the plates. The plates are secured together by rivets which are spaced along and traverse the deformed portions of the plates, thus providing a spring section to absorb unequal expansion of the plates and the fluid conducting pipes. The uppermost surface of the pair of plates is provided with a black body coating to emit infrared radiation when sunlight is incident thereon. A glazing is provided over such black body surface to freely transmit incident light to the black body surface but to reflect infrared heat energy emitted by the black body surface. Water or other heat transfer liquid flowing through the pipes is maintained at a sufficiently high pressure to produce a turbulent flow through the pipes to increase the efficiency of the heat transfer.