Absorption heat pumps use an ammonia-h2o absorption cycle, in lieu of a vapor-compression cycle, to transfer heat. Ammonia may be the refrigerant, and water would be the absorber. The ammonia condenses at among the process’s coils to launch heat and evaporates at another coil to soak up heat. Heat exchange: https://purethermal.co.uk/media-news/can-gas-absorption-heat-pumps-provide-an-alternative-heat-pump-option-in-2025/