Being an air to water monobloc heat pump, it operates successfully applying eco-friendly R290 refrigerant, delivering sustainable heating with a formidable A+++ Electricity effectiveness score. Break up Systems: Have one coil and supporter inside and 1 exterior. Supply and return ducts hook up with the indoor central coil and admirer. https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/