Utilizes Digital enlargement valve to exactly Manage the circulation of R290 refrigerant into your evaporator in addition to a 4-way valve to divert the refrigerant circulation with the defrost Procedure An air-to air process could be built to transfer heat in both way, to heat the interior of the constructing https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/