Additional subcooling will be achieved by heat exchange between relatively warm liquid refrigerant leaving the condenser and the cooler refrigerant vapor emerging from the evaporator. When the increase in cooling achieved by subcooling is larger that the compressor drive enter required to beat the extra strain losses, such a heat alternate improves the coefficient of efficiency. The "seasonal coefficient of efficiency" (SCOP) is a measure of the aggregate vitality effectivity measure over a inte...