How long has ammonia been used as a refrigerant?
Ammonia was among the early refrigerants used in mechanical systems, and it’s the only one of the early refrigerants to secure a lasting role as a refrigerant. Mechanical refrigeration was developed in the 1800s based on the principle of vapor compression. The first practical refrigerating machine using vapor compression was developed in 1834 and by the late 1800s refrigeration systems were being used in breweries and cold storage warehouses. The basic design of the vapor compressor refrigeration system, using ammonia as a refrigerant in a closed cycle of evaporation, compression, condensation, and expansion, has changed very little since the early 1900s.