Decreasing the refrigerant super-heating degree at the outlet of the suction line heat exchanger can reduce the evaporator size, but it simultaneously increases the refrigerant mass flow rate and compressor power.

• 降低制冷工质在回热器出口处的过热度；可以减小蒸发器的尺寸；但由此带来的不利因素；是需要增加制冷工质的质量流量以及提高压缩机的压缩功率.