Being an air to h2o monobloc heat pump, it operates effectively utilizing eco-pleasant R290 refrigerant, giving sustainable heating with a powerful A+++ Electrical power efficiency rating. The ECOMOD 290HT variety of monobloc air source heat pumps come in 3 chassis measurements and 5 outputs: 15kW, 18kW, 27kW, 40kW and 50kW. https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/