Abstract: A solar collector comprising a heat collecting panel for receiving the sunlight, a cover glass arranged above the panel, and a sunlight-pervious diaphragm disposed between the panel and cover glass to form a closed space between itself and the cover glass, the diaphragm being adapted to expand and contract to vary the volume of the closed space, whereby the pressure in the closed space is kept substantially equal to the atmospheric pressure. With this arrangement, since the collector does not permit the entry of humid ambient air into the closed space, no condensates will be produced on the inner surface of the cover glass. Further, if the diaphragm is adapted to sag and contact the panel due to its expansion at the time of abnormal heating, heat dissipation from the panel is accelerated. Thus damage to the panel due to overheating can be prevented.

Abstract: An absorption type refrigeration system includes a main flow circuit, a first and a second auxiliary flow circuit. The main flow circuit includes a refrigerant generator containing a solution of evaporable refrigerant in a less evaporable solvent which is heated by solar energy. Pressurized vapor phase refrigerant is supplied to a main condenser and thence to a main evaporator and back to an absorber in which a low refrigerant content solution from the generator is converted to a high refrigerant content solution which is pumped to the generator for recirculation. An electrically driven compressor supplies vapor phase refrigerant through the first auxiliary flow circuit including a condenser, a diaphragm-operated expansion valve, and a first auxiliary evaporator which is arranged to cool the main condenser.

Abstract: A method for making a selective absorption film for solar energy which comprises immersing aluminum or its alloy in water which contains at least two members selected from phosphate ions, fluoride ions and triethanolamine, and optionally ions of a metal selected from copper, iron, cobalt, silver and a mixture thereof thereby forming a chemical conversion film which shows a great absorptivity and a small emissivity.

Abstract: According to the present invention, in a hybrid type refrigerating cycle having a compressor disposed between a refrigerant vapor generator of an absorption type refrigeration cycle and a condenser, a refrigerant reservoir is disposed after the condenser. The refrigerant liquid level inside the refrigerant reservoir is detected to properly control the start of operation or the suspending of operation of the compressor thereby to end wasteful power consumption, thus ensuring smoother operation of the refrigerating machine.

Abstract: A system to accomplish both air cooling and air heating of indoor space by utilizing solar energy. In principle the disclosed system is an absorption refrigeration system, wherein a solution of an evaporable refrigerant in a less evaporable solvent is passed through a solar collector-generator, but the system has additional fluid passages with the provision of changeover valves arranged so as to pass the refrigerant in heated and vaporized state from the collector-generator to an indoor heat exchanger, bypassing the condenser of the refrigerator, thereby to accomplish air heating and return the refrigerant in liquid state from the heat exchanger to the collector-generator, bypassing the absorber of the refrigerator.