In the dry method, this heat is circulated as heat air via ducts and vents. Air-to-air heat pumps can flow into either warm or cold air. Employing electricity, the pump compresses the liquid to raise its temperature. It then condenses again right into a liquid to release its stored heat. https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/