Abstract: A reverse cycle heat reclaim coil in a refrigeration system having compressor, condenser and receiver means on the high side, including first valve means for selectively connecting the heat reclaim coil between the compressor discharge side and the condenser means to obtain heat reclamation during winter operations, and second valve means for selectively connecting the heat reclaim coil between the condenser and receiver means to obtain refrigerant subcooling during summer operations. The invention also includes the method of selectively connecting the heat reclaim coil in reverse cycle refrigerant flow in seasonal heat reclamation and subcooling modes.

Abstract: A flow-through surge receiver for a refrigeration system having compressor, condenser and evaporator means, in which a surge-type receiver forms a reservoir for liquid refrigerant and has a flow-through conduit receiving refrigerant from the condenser means and an outlet for passing such refrigerant directly to the evaporator means in by-pass relation with the receiver reservoir, and a passageway for establishing fluid communication between said conduit and reservoir below the normal liquid refrigerant level in the reservoir.

Abstract: An oil return system for a multiple compressor refrigeration system in which said compressors have a common discharge and at least two of said compressors have their low pressure suction side connected to operate at substantially different suction pressures, said oil return system having oil and refrigerant separating means connected to receive the common discharge from said compressors and oil delivery means constructed and arranged to maintain compressor oil levels at the suction side of the respective compressors, and oil control valve means disposed between said separating means and oil delivery means for each of said two compressors, said oil control valve means for each such compressor having pressure means for maintaining the downstream oil pressure to the oil delivery means at a preselected value.

Abstract: A refrigeration system having compressor, condenser, surge receiver and multiple evaporator means, and high side control means including gas defrost means for selectively defrosting the evaporator means with saturated refrigerant gas, a surge control valve for the surge receiver means, and other means for operating the surge control valve in response to differential high side pressures, liquid levels in the receiver means and/or gas defrost operations to regulate refrigerant pressures within the surge receiver means.

Abstract: An oil separator unit for use in an oil separation and return system for the compressor means of a refrigeration system, including a unitary oil separation and oil accumulator vessel having an upper vortex separation chamber, oil collecting and separating means, vapor deflector means, oil precipitation means, and a lower oil accumulator chamber for receiving and holding liquid oil.

Abstract: A pressure regulating valve for use in the oil separation and delivery system of a refrigeration system, including a valve body having an oil inlet chamber for connection with a separated liquid source on the high pressure side of refrigeration system compressor means, an oil outlet adapted for low pressure connection with oil level controls for the compressor means, internal valve means for controlling oil flow between the high side and low side chambers, and movable pressure means responsive to oil outlet pressure and compressor suction pressure acting in opposition for regulating said internal valve means.

Abstract: A climatic control system for the seasonal heating and cooling of air circulated through a temperature control chamber, including a three coil heat pump having a cooling mode coil and a separate heating mode coil positioned in the chamber for selective operation, and a heat reclaim condenser coil of a separate refrigeration system positioned between the cooling and heating mode coils for selective operation therewith.

Abstract: An oil separation system for a refrigeration system having compressor, condenser-receiver and evaporator means, including an oil separator having a vortex separation chamber disposed in the refrigerant gas discharge line between the compressor means and condenser-receiver means, an oil reservoir for receiving oil from the separation chamber, and oil control means for maintaining a predetermined oil level in the compressor means including a pressure differential valve for regulating the flow of oil from the reservoir to the compressor means.