Makes use of Digital expansion valve to precisely Management the movement of R290 refrigerant in the evaporator in addition to a 4-way valve to divert the refrigerant stream for your defrost Procedure That’s why the UK authorities are supplying fiscal incentives for those who make the swap to sustainable heating https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/