Subcool

Subcool, in HVAC and refrigeration, refers to the amount of cooled liquid refrigerant below its boiling (saturation) temperature as it enters the expansion device. This subcooled liquid is slightly colder and more condensed, ensuring it remains a liquid upon entering the evaporator, which improves cooling efficiency. Proper subcooling prevents refrigerant from vaporizing prematurely, allows precise control of system performance, and helps maintain optimal energy use. Maintaining the correct level of subcooling is important for system reliability, efficiency, and preventing damage to components.