Absorption heat pumps use an ammonia-drinking water absorption cycle, in lieu of a vapor-compression cycle, to transfer heat. Ammonia is definitely the refrigerant, and water may be the absorber. The ammonia condenses at one of several procedure’s coils to launch heat and evaporates at one other coil to absorb heat. https://purethermal.co.uk/media-news/can-gas-absorption-heat-pumps-provide-an-alternative-heat-pump-option-in-2025/