For maximum system efficiency, the TEV superheat for a cooler should be about:

The optimal superheat setting for a thermal expansion valve (TEV) in a cooler is typically in the range of 8-10 degrees. This range is considered ideal because it allows the system to effectively manage refrigerant flow into the evaporator while ensuring that the refrigerant is fully vaporized before leaving the evaporator coil. Operating at this superheat level maximizes the efficiency of the cooling cycle.

When the superheat is at 8-10 degrees, it indicates that there is just enough heat added to the refrigerant to ensure it is in gaseous form, which prevents the liquid refrigerant from reaching the compressor. This is crucial for protecting the compressor from damage due to liquid slugging. Furthermore, this level of superheat helps in maintaining an efficient heat exchange process within the evaporator, thereby optimizing the overall cooling performance of the refrigeration system.

Choosing a superheat setting closer to this range minimizes the risk of compressor damage and ensures that the system operates within its designed capacity, leading to better energy efficiency and longevity of the equipment.