Which condition would likely indicate a need for superheating in a refrigeration system?

Superheating in a refrigeration system is a process used to ensure that only vapor enters the compressor, preventing potential damage and maintaining efficiency. When there is an absence of liquid refrigerant in the low side refrigerant line, it indicates that the refrigerant is not adequately absorbing heat in the evaporator coil and is entirely vapor when it reaches the compressor.

This condition suggests that the system is operating under low refrigerant levels or has inefficient evaporator performance, leading to insufficient cooling and the potential for compressor overheating. Superheating the vapor ensures that any remaining liquid refrigerant is converted to vapor before it reaches the compressor, which is crucial for maintaining functionality and preventing liquid slugging.

In this context, the absence of liquid refrigerant signifies a problem that requires superheating to improve refrigerant flow, enhance the efficiency of the system, and protect the compressor from damage, making it the appropriate indicator for the need for superheating.