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