Heat exchanger effectiveness can impact the efficiency of vapor-compression cycles used in air conditioners, heat pumps, refrigeration equipment, and refrigerators. As the refrigerant condensing or evaporating temperature approaches that of the ultimate heat transfer medium, e.g., the outdoor air temperature for an air-cooled condenser, the vapor compression cycle temperature difference (also referred to as the lift) decreases. This, in turn, decreases the pressure ratio across the compressor, increasing its operational coefficient of performance (COP) and decreasing its energy consumption.