Numbering of refrigerants
The numbering of refrigerants is based on the original numbering system for fluorocarbons, which was developed in the 1930s by DuPont and adopted by the entire field in 1956.
Since then, it has also been accepted in the ANSI/ASHRAE system as part of Standard 34 (Number Designation and Safety Classification of Refrigerants).
The numbering system provides technicians and engineers with an easy way to identify the chemical composition of a refrigerant. Each number in the system has its own meaning in the identification of the compounds that form the refrigerant.
The basic structure begins with the “chemical group” of the substance, followed by a dash (-) and a string of numbers and letters. The dash is also commonly omitted. For example, HFC-134a consists of the group identifiers “HFC” and “134a”, indicating the chemical composition of the substance. Simply the identifying letter “R” is also often used instead of the chemical group, in which case HFC-134a becomes R134a.
Grouping of refrigerants
- 000 series: methane-based compounds
- 100 series: ethane-based compounds
- 200 series: propane-based compounds
- 300 series: cyclic organic compounds
- 400 series: zeotropes
- 500 series: azeotropes
- 600 series: organic compounds
- 700 series: inorganic compounds
- 1000 series: unsaturated organic compounds.
For example, HCFC-22 is in the “000 series” of refrigerants, meaning it is a methane-based compound. R-134a is in the “100 series” of refrigerants, meaning it is an ethane-based compound. R290 is part of the 200 series of propane-based compounds, etc.