Abstract: A thermosyphon heat pipe hot water appliance combines a solar collector with a heat reservoir wherein fluid vaporized in the collector transfers latent heat to reservoir fluid, for re-transfer to fluid such as water supplied by city reservoirs, or from municipal mains.
Abstract: Heat transfer structure comprises:A. sandwich assembly including a heat transfer plate to receive infra-red radiation or to transmit such radiation, respectively to or from skyward,B. the assembly defining an enclosed gas flow chamber at the underside of said plate, there being spaced air inlet and outlet ports respectively to and from the chamber, andC. baffling in said chamber to direct gas passing through the chamber via said ports to freely flow tortuously and with turbulence adjacent major extent of the underside of said plate.