What typically causes high superheat in a refrigeration system?

High superheat in a refrigeration system typically indicates that the refrigerant has been vaporized completely before it has absorbed the designed amount of heat in the evaporator. Inadequate refrigerant charge is a common cause of this condition. When there is not enough refrigerant in the system, the evaporator coil does not receive sufficient refrigerant to absorb heat effectively. As a result, the refrigerant exits the evaporator at a higher temperature than desired, leading to an increase in superheat. This situation can reduce system efficiency and potentially damage the compressor due to overheating.

Other factors can influence superheat, but they do not typically lead to sustained high superheat levels like an inadequate charge does. Low ambient temperatures, for example, can affect system performance but don't inherently cause high superheat directly. A leaking liquid line solenoid may disrupt refrigerant flow, impacting overall system function, but it is less likely to consistently cause high superheat. Similarly, an improperly sized evaporator coil can lead to various issues in a refrigeration cycle, but often it would create low superheat or problems with the system's heat exchange rather than strictly high superheat.