Focus Article - Good-Bad-Ugly of Ammonia Refrigeration
Ammonia (R-717) was among the early refrigerants, first used in 1850 in France(2). It was introduced in the US in the 1860s for artificial ice production, after which the first ammonia refrigeration machines were patented in the 1870s. Ammonia is one of the early chemicals to secure a lasting role as a refrigerant. It is still used today in large, commercial cooling applications.