the lefthand side of convector 10 39 fig2 c shows a pair of convectors 10 and 10 39 exposed to rays r oriented diagonally downward so as to impinge upon the righthand surfaces of convectors 10 and 10 39 and being reflected as represented by rays r 39 so as to strike the lefthand surface of convector 10 39 fig3 a 3b and 3c show the convectors being arranged so that their central axes lie on an imaginary vertical plane wherein the individual convectors are rotated in fig3 a so that their fins all lie in a common vertical plane whereas the fins lie in spaced parallel horizontally aligned planes as shown in fig3 b and whereas the fins are arranged in spaced parallel planes which are diagonally aligned as shown in fig3 c from the orientations of fig2 a and 2c and 3a through 3c it can be seen that the convectors when rotatably mounted are adapted to capture radiation with a high degree of efficiency regardless of the orientation of the solar collector housing as will be described in greater detail hereinbelow fig4 a is a schematic diagram showing the manner in which the modular design solar collector assembly may be integrated into a system for utilizing solar energy.