A refrigeration system with a restriction in its capillary tube is likely to exhibit which condition?

In a refrigeration system, a capillary tube functions as an expansion device, allowing the refrigerant to expand and reduce its pressure as it enters the evaporator. When there is a restriction in the capillary tube, it reduces the flow of refrigerant through the system. This limited flow can lead to an increase in the superheat of the refrigerant.

Superheat refers to the temperature of the refrigerant vapor above its boiling point at a given pressure. With reduced refrigerant flow caused by the restriction, the evaporator may not fully utilize the refrigerant, resulting in it absorbing more heat and becoming Superheated before it returns to the compressor. As a result, the refrigerant reaches a higher temperature than desired, which can potentially lead to inefficiencies and increased wear on the compressor.

This condition underscores the importance of maintaining proper refrigerant flow for effective system operation. While other conditions like low pressure or humidity can arise in refrigeration systems, the specific consequence of a restriction in the capillary tube is an increase in superheat, making high superheat the correct answer in this scenario.