... unit included 4 way valve, liquid storage tank, pcb, heat exchanger, auxiliary heater, pressure gage, compressor inside the indoor unit ... function, auxiliary heater also work during defrosting, our PCB with the control of the auxiliary heater, that is as a electric ... and energy savingUsing high-efficient compressor rotary or scroll and heat exchanger (316 stainless steel brazing type, high-efficient S ...