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