Industrial refrigeration is a vast topic by itself and there are number of types based on the components and materials used. There are 2 major types of industrial refrigeration, they are direct and indirect. In direct industrial refrigeration the product itself is compressed and condensed to form a liquid. The product itself is the refrigerant. Propane and ethane are used as refrigerants for refrigeration in petrochemical industry. These industries mostly use centrifugal condenser. Configuring and installation of all these components are done by professional trained in refrigeration engineering. Other way is indirect industrial refrigeration in which a separate refrigerant is used for the cooling effect. Ammonia is one such refrigerant and when Ammonia is used then it is called as Ammonia industrial refrigeration. Skid mounted packages are filled with some refrigerants and used for cooling purpose.
These skid mounted packages are filled with Ammonia and many other refrigerants. For example if you consider a normal ice cream factory then that would require Ammonia refrigeration system of 200 to 300 tons of capacity and would require 1500 HP compressors. Usually systems with Ammonia refrigeration with capacity more than 10,000 pounds ammonia then is covered under specific requirements of process and safety standards and the industrial refrigeration systems are built based on these systems.