In a very dry process, this heat is circulated as warm air via ducts and vents. Air-to-air heat pumps can circulate both hot or cold air. One or more[nine] indoor condenser heat exchanger coils. They transfer the heat into the indoor air, or an indoor heating program like water-stuffed radiators https://purethermal.co.uk/media-news/q4-launch-lithium-large-capacity-r290-ashp-from-pure-thermal-and-enerblue/