Ammonia has been used as a refrigerant in industrial refrigeration facilities since the beginning of the 20th century. This refrigerant has very good energy yields and is also not harmful to the ozone layer, since its composition is kept very little time in the atmosphere, so we could classify it as a biodegradable gas. Also, the cost of ammonia is much lower than any of the synthetic gases on the market.
The working pressures of ammonia are comparable to those of other common refrigerants (HFC and HC), and their boiling point is relatively normal (-33.3 ° C). Ammonia has a high volumetric capacity, so ammonia pipes are smaller than those of HFC refrigerants. However, it should be noted that, when ammonia is used in suction lines, the pipes are larger than those needed for CO2.