Which of these describes a function of superheat?

Superheat is an important concept in HVAC systems, particularly within the refrigeration cycle. One of its main functions is to ensure that the refrigerant vapor reaching the compressor is completely vaporized and does not contain any liquid. This is crucial because if liquid refrigerant were to enter the compressor, it could cause damage or catastrophic failure, as compressors are designed to compress vapor, not liquid.

By maintaining a certain amount of superheat, the system safeguards the compressor while optimizing its performance. Superheat is measured by the difference between the saturation temperature of the refrigerant at a given pressure and the actual temperature of the refrigerant vapor as it exits the evaporator. This ensures that there is enough thermal energy in the vapor form to prevent any liquid from returning to the compressor.

While the other options may relate to certain aspects of HVAC performance or refrigerant behavior, they don’t directly define the function of superheat in the same critical way that preventing liquid refrigerant from returning to the compressor does. For instance, superheat does help provide additional cooling and affects pressures in the cycle, but its primary role is centered around avoiding liquid refrigerant in the compressor, which is key to the longevity and reliability of HVAC systems.