When should a refrigerant recovery machine be used?

A refrigerant recovery machine should be used when servicing or repairing refrigeration systems because its primary purpose is to safely remove refrigerant from the system and store it for reuse or proper disposal. This is essential to prevent environmental contamination and to comply with regulations regarding refrigerant handling.

Using the machine during service ensures that the refrigerant does not escape into the atmosphere, which can contribute to ozone depletion and global warming. The recovery process also allows technicians to maintain a controlled environment while diagnosing and fixing issues within the system.

The other options do not align with the primary function of a refrigerant recovery machine. Testing cooling efficiency and measuring refrigerant levels do not require the removal of refrigerant from the system, while cleaning the condenser generally involves maintenance practices without the need for refrigerant recovery. Therefore, the requirement to use a recovery machine is specifically tied to the servicing and repair of the refrigeration systems to ensure compliance and safety.