Abstract: A multiple source energy recovery system incorporating a finned heat exchanger having a plurality of primary fluid circuits, at least some of which are connected to waste heat sources. A heated medium in a secondary fluid circuit is stored in a tank and then circulated to a second heat exchanger where the waste heat is recovered and utilized.

Abstract: A heat pump system uses a non-reversing refrigeration circuit having a water-cooled condenser and a counterflow chiller fed by a thermostatic expansion valve to permit operation at close to zero superheat. To protect the compressor in the refrigeration circuit from possible flood-back at this low superheat, a combination suction-liquid heat exchanger-suction accumulator is employed. A hold-back valve serves to maintain constant compressor suction pressure regardless of evaporator pressure fluctuations caused by changing chiller fluid temperatures. The system is designed to operate in four distinct modes: (1) water source heat pump heating; (2) direct solar heating; (3) air source heat pump heating; and (4) heat pump cooling. To switch the refrigeration circuit to heat pump mode from the cooling mode or vice versa, four three-way valves and three fluid pumps are selectively operated. The fluid circuit of the system consists of two separate coils in an air-handling unit.

Abstract: A compression-type refrigeration system which utilizes the conventional suction line of such a system as a defrost conduit at periodic intervals and which incorporates an auxiliary heat exchanger which (1) can act to subcool the condensed refrigerant during a refrigeration cycle and (2) acts to heat the refrigerant coming from the receiver of the system during a defrost cycle.

Abstract: A heat collector for absorbing solar energy includes a hollow panel with an insulated backwall connected to a cover plate by insulated spacer side walls. A conduit extends to and fro between opposed side walls in the space between the cover plate and the backwall. Spaced-apart heat transfer fins are in intimate heat conductive contact with the conduit. The fins extend in a generally radial direction from the conduit and include bent fin portions that project in a coplanar manner along the space between the conduit and the backwall within a plane which is generally normal to incident beam radiation. In one embodiment, the unbent portion of the fins projects within an included acute angle from the face surface of the conduit; while in the second embodiment, the included angle is a right angle.

Abstract: A heat pump having an auxiliary outdoor coil equipped with heating means preventing the surface temperature during the heating cycle from falling below 32.degree. C. The heating means comprises an electrical resistance heater in thermal contact with the fins of the outdoor coil such that heat is transferred to the fins by conduction. The system incorporates means to permit functioning immediately upon return to the heating cycle from a cooling cycle even though the pressure in the receiver of the system initially exceeds that in the indoor coil. Additionally, the system incorporates means for protecting the compressor from liquid floodback when changeover occurs from heating to cooling.