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