The History of Ammonia Refrigeration

 How common is ammonia refrigeration?
Many years ago, the food and beverage industry embraced ammonia refrigeration. The economic advantages alone made it the refrigerant of choice for cold storage facilities and food processing facilities as well as the dairy and meatpacking industries. Almost all of the food on the family breakfast, lunch and dinner table passes through an ammonia refrigeration facility before reaching your grocery store including fresh fruits and vegetables, meat, poultry and fish, frozen convenience foods, milk, cheese and ice cream, and beverages such as soft drinks, beer and wine.
When was ammonia first synthesized?
Ammonia was first synthesized in 1823 by reacting air and hydrogen. The first commercial production of synthetic ammonia began in 1913. Presently, there are an estimated two billion metric tons of ammonia present in the world. Of this amount, approximately five percent is man-made. Approximately 18 million metric tons of ammonia are produced annually in North America alone, and of this amount, less than two percent is used for refrigeration.
When was the first commercial use of ammonia refrigeration?
Ammonia was first used as a refrigerant in the 1850s in France and was applied in the United States in the 1860s for artificial ice production. The first patents for ammonia refrigeration machines were filed in the 1870s. By the 1900s, ammonia refrigeration machines were being commercially installed in block ice, food processing, and chemical production facilities. By the 1920s, ammonia refrigeration was being applied to ice rinks. During the 1930s, air conditioning markets began to develop, first for industrial applications and then for human comfort. The use of smaller units for domestic refrigerators increased substantially between 1920 and 1930.
Does ammonia refrigeration have other modern day uses?
Recently, air conditioning provided by ammonia refrigeration systems has found applications on college campuses and office parks, small scale buildings such as convenience stores, and larger office buildings. These applications have been achieved by using water chillers, ice thermal storage units, and district cooling systems. In Europe, where regulatory regimes have encouraged new applications, ammonia refrigeration systems are used safely for air conditioning in hospitals, public buildings, airports, and hotels.
Ammonia refrigeration provides air conditioning for the International Space Station and Biosphere II. Installation at power generation facilities represents an emerging application of ammonia refrigeration.

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.

Why is ammonia referred to as a natural refrigerant?
Ammonia is a common, naturally occurring compound in the environment that breaks down naturally into hydrogen and nitrogen molecules (the atmosphere consists of nearly 80% nitrogen and hydrogen). Ammonia is made up of one atom of nitrogen and three atoms of hydrogen, with the chemical symbol NH3. Ammonia is a key element in the nitrogen cycle, and under normal conditions, is essential for many biological processes. Ammonia can be found in water, soil, and air, and is a source of much needed nitrogen for plants and animals. In fact, ammonia is among the most abundant gasses in the environment.
How is ammonia refrigeration used today?
Ammonia refrigeration has been the backbone of the cold storage and food processing industries since the early 1900s. Ammonia refrigeration is the most cost effective and energy efficient method of processing and storing frozen and unfrozen foods. It is the workhorse for the post-harvest cooling of fruits and vegetables, the cooling of meat, poultry, and fish, refrigeration in the beverage industry, particularly for beer and wine, refrigeration of milk and cheese, and the freezing of ice cream. Practically all fruits, vegetables, produce and meats, as well as many beverages and juices, pass through at least one facility that uses an ammonia refrigeration system before reaching our homes. Ammonia refrigeration is also used in the chemical industry.