Abstract: A solar heat collection device comprising collectors arranged to be fixedly disposed as sub-collectors each of a set of at least two of such collectors, with one longitudinal edge of their screen adjoining one another. The sub-collectors are of identical construction and each designed to collect solar heat during an associated sub-period of at least two consecutive sub-periods of the solar day. Each sub-collector contains a primary liquid heating tube and a separate, secondary liquid heating tube parallel to said primary liquid heating tube and connected in series with said primary liquid heating tube in the bottom part of the sub-collector. In cross-section, the two tubes adjoin one another in the direction of depth of the sub-collector and extend, in that direction, from the deepest part of said trough for a joint height which is no greater than approximately one-fourth of the aperture width of the sub-collector, measured between the longitudinal edges thereof.

Abstract: A solar heat collector provided with an elongate circumferential wall of generally semi-circular shape in cross section, which wall at the concave side comprises a reflective surface of, likewise in cross section, at least substantially semi-circular shape, with heat collection provisions within the space defined by the circumferential wall and two collector end walls disposed at the collector ends, as well as with a solar radiation-transmissive cover before the collection opening formed between the free longitudinal edges of the reflective surface, which heat collection provisions extend within a flat portion of the space within the semi-circular portion of the reflective surface, in the direction transversely to the median plane of the reflective surface, vertically in the North-South direction, over substantially the entire median plane, insofar disposed within the said portion of said space.

Abstract: An installation for storing and transmitting heat of a fluid heated by solar radiation, said installation being provided with a fluid tank and contained in said tank heat exchanging means for heat exchange between the heated fluid supplied through a pipe and the fluid in the tank. The heat exchanging means comprise at least two, preferably three, heat exchangers disposed in associated zones at ascending levels in the tank, corresponding to ascending temperature ranges of the fluid in the tank, and in each of said zones, for transmission of heat therefrom, spaced apart above the respective heat exchanger at least one further transmission heat exchanger for heat exchange between the fluid and water of the temperature associated with the respective temperature range.