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