Uses electronic growth valve to exactly control the circulation of R290 refrigerant into your evaporator as well as a four-way valve to divert the refrigerant stream for your defrost operation By Pressing submit, I consent that my facts be shared with Trane approved affiliates and 3rd party companions, together with https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/