During an engine-room walk-through, excessive superheat at the evaporator outlet could most likely be caused by?

Excessive superheat at the evaporator outlet indicates that the refrigerant is not absorbing enough heat in the evaporator, which can lead to inefficiencies in the refrigeration cycle. This situation can occur due to a variety of reasons.

Inadequate airflow can prevent the evaporator from transferring sufficient heat to the refrigerant. If the airflow is restricted or insufficient, the heat exchange process is compromised, leading to the refrigerant leaving the evaporator at a higher temperature than desired, resulting in excessive superheat.

Improper refrigerant charge is another critical factor. If the system is overcharged or undercharged with refrigerant, it can affect the evaporator's ability to absorb heat efficiently. An undercharge can lead to low pressure and temperature at the evaporator inlet, while an overcharge can flood the evaporator and make it inefficient, both resulting in high superheat.

A faulty evaporator itself, such as one with leaks or blockages, can impede the proper heat exchange process. If the evaporator isn’t functioning correctly due to physical damage or wear, it may not facilitate proper heat absorption, also contributing to high superheat.

Therefore, the answer indicates that all these factors—poor airflow, improper refrigerant charge, or a defective evapor