Ammonia refrigeration systems are gaining popularity these days due to their various advantages such as lower evaporation temperature and less environmental stress. An ammonia refrigeration cycle is basically an absorption refrigeration cycle in which ammonia is used as the refrigerant. In the absorption cycle a heat source is utilised to provide the energy which is required to run the cooling system. These refrigerators have gained a wide popularity in industries since they reduce the electricity expenditure.

An ammonia refrigerator is similar to a regular compression refrigerator in that the refrigeration happens due to the evaporation of a liquid with a sub-zero boiling point. When a liquid evaporates or boils, it absorbs heat and this happens either until the entire liquid volume is boiled or until the area to be cooled reaches the sub-zero boiling point of the refrigerant. However there exists a difference between the two types of industrial refrigeration in the manner by which the gas is changed into a liquid form for re-use. In an absorption refrigerator this is done by utilising heat, and as such no moving parts exist.