Ammonia — also known as azane4 or R7172 — was among the early refrigerants, first used in 1850 in France1 in mechanical systems. A decade later, it was utilized in the United States for artificial ice production, and 10 years after that, the first ammonia refrigeration machines were patented in the 1870s. An early refrigerant, it also was one of the earliest to secure a lasting role as a refrigerant.
Ammonia is widely used in the process industries. The food and beverage industry utilizes ammonia refrigeration for their cold storage, food processing, dairy and meatpacking facilities. Ammonia refrigeration is also utilized for ice rinks, early household refrigerators, college campuses, office parks, convenience stores and larger office buildings. Ammonia refrigeration also is used at the international space station and Biosphere II — and is even being employed in power generation units.1