Works by using electronic expansion valve to precisely Regulate the movement of R290 refrigerant into your evaporator as well as a 4-way valve to divert the refrigerant stream for your defrost Procedure Employing energy, the pump compresses the liquid to increase its temperature. It then condenses back into a liquid https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/