Where is refrigerant added back into a Type III chiller after recovery?

In a Type III chiller system, refrigerant is added back after recovery through the evaporator's charging valve. This is because the evaporator is where the refrigerant absorbs heat from the environment, and charging it at this point allows for the proper handling and mixing of the refrigerant within the system.

Adding refrigerant here ensures that it enters into the evaporator where it is intended to evaporate and facilitate heat exchange. Properly filling the system at the evaporator’s charging valve also helps avoid issues with pressure imbalances and allows the technician to monitor the system more easily during the charging process.

In contrast, the other locations do not serve the same purpose for adding refrigerant in a Type III chiller configuration. The condenser unit is primarily responsible for the release of heat, thus not an ideal spot for introducing refrigerant. The compressor service port is generally used for measuring system pressures and is not intended for charging. Lastly, the low-pressure switch is a safety device that protects the system from operating under dangerously low pressure conditions, making it unsuitable for adding refrigerant.