... unit included 4 way valve, liquid storage tank, pcb, heat exchanger, auxiliary heater, pressure gage, compressor inside the indoor ... energy savingUsing high-efficient compressor rotary or scroll and heat exchanger (316 stainless steel brazing type, high-efficient ... S&C, high-efficient heat exchanger tube), small volume, high heat enchanger, up 10% than the same old units. Environment ...