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