In refrigeration, what does the term “superheat” refer to?

Superheat refers to the temperature rise of a vapor above its saturation point—the temperature at which a substance transitions from a liquid to a gas. In refrigeration systems, superheating is significant because it ensures that the refrigerant vapor maintains its gaseous state as it moves through the evaporator coil. This process helps prevent liquid refrigerant from returning to the compressor, which can cause damage.

In practical terms, superheat is measured as the difference between the actual temperature of the refrigerant vapor and the saturation temperature corresponding to its pressure. Adequate superheat indicates that the refrigerant has absorbed sufficient heat energy, enhancing system efficiency and performance.

This understanding is critical in refrigeration because it affects both system reliability and capacity. Inadequate superheat could lead to poor performance or compressor damage, while excessive superheat may indicate that the refrigerant is not absorbing enough heat, leading to inefficient operation.