Abstract: An automatic charge or recharge refrigerant transfer system, increases the percentage of refrigerant transferred from a container to the air conditioning unit to be charged. The suction line of the compressor of the air conditioning unit is connected to the discharge of the transfer unit and the discharge of the recovery system is connected to the intake of the transfer unit. The intake of the recovery system is connected to the refrigerant source. The transfer system has an automatic flow path, a manual flow path and a return flow path. The automatic flow path automatically controls the flow of refrigerant from the source through the recovery system to the air conditioning unit at a predetermined maximum pressure level. The parallel manual flow path permits use of a hand valve to control the flow of refrigerant from the source through the recovery system to the air conditioning unit.

Abstract: A circuit for recovering refrigerant from a disabled refrigeration unit combines a vacuum pump, vapor pump or compressor in series with a compressor for drawing gaseous refrigerant from the disabled unit. The series arrangement of the vacuum source and the compressor provides approximately -29 inches of mercury at the suction side of the vacuum source. A condensor in series with the compressor converts the gaseous refrigerant into a liquid refrigerant and a storage tank in series with the condenser receives liquid refrigerant from the condenser. In one preferred arrangement a valve system connected in series between the condenser and the storage tank allows the storage tank to be disconnected from the circuit without release of refrigerant from the tank to the atmosphere. The circuit may also include a coil in parallel with the condenser and the compressor and helically disposed around the storage tank for cooling the storage tank.