Makes use of Digital expansion valve to exactly Handle the movement of R290 refrigerant in to the evaporator in addition to a four-way valve to divert the refrigerant movement for your defrost Procedure The set up crew had been good, clean, and caring and did a superb qualified and professional https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/