the number “1”, as the presence of a double bond in the backbone of the molecule has priority over substituent groups on the molecule.
Table 2.2 Examples of main commercial classes of fluorocarbons [7].
| Fluorocarbon type | Description | Applications |
| CFC | Substance that contains chlorine and has strong characteristics of destroying the ozone layer. Examples: CFC-11, 12, 113 etc. | It has been widely used with refrigerant, blowing, solvent, and aerosol propellant, but in accordance with Montreal Protocol, those have been completely banned production and imports by the end of 1995. |
| HCFC | It contains chlorine but it also contains hydrogen, therefore propensity to destroy the ozone layer is considerably weakened (low ODP).Examples: HCFC-22, 123, 141b, 142b etc. | It has been widely used with refrigerant, blowing, solvent, and aerosol propellant, but in accordance with Montreal Protocol, those are on the way of total abolition. Depending on types and uses, some have been totally abolished. (Example, HCFC-141b for PU blowing agent) |
| HFC | It does not contain chlorine and has hydrogen that does not destroy ozone layer. Examples: HFC-23, 32, 125, 134a, 143a, 152a etc.HFC blend refrigerants R-410A, 407C, 404A. | Refrigerant: Refrigerator, various refrigeration equipment, mobile airconditioning, room air-conditioner, package air-conditioner etc. Blowing agent, solvent, and aerosol propellant. |
| HFO | It does not contain chlorine and has hydrogen. Does not destroy ozone layer. Plus it has no impact on global warming Examples: R-1234yf (CF3CF=CH2), R-1234ze (CF3CH=CHF). | Refrigerator, various refrigeration equipment, mobile air-conditioning, room air-conditioner, package airconditioner etc. Blowing agent, solvent, and aerosol propellant. |
In the case of isomers of propene series, each has the same number, with the isomers distinguished by two appended lowercase letters. The first appended letter indicates the substitution on the central carbon atom:
| - Cl | x |
| - F | y |
| - H | z |
Table 2.3 List of hydrochlorofluorocarbon (HCFC) refrigerants [8].
| Product R-Number | ODP | GWP | |
| 22 | 0,055 | Medium | 1810 |
| 123 | 0,060 | Medium | 77 |
| 401A | 0,033 | Medium | 1182 |
| 401B | 0,036 | Medium | 1288 |
| 402A | 0,019 | Medium | 2788 |
| 402B | 0,030 | Medium | 2416 |
| 408A | 0,024 | Medium | 3152 |
| 409A | 0,046 | Medium | 1909 |
The second letter designates the substitution on the terminal methylene carbon as defined for the methylene carbon of the propane:
| =CCl2 | a |
| =CClF | b |
| =CF2 | c |
| =CHCl | d |
| =CHF | e |
| =CH2 | f |
The following schematic summarizes the nomenclature for hydrofluoroolefins:
In the cases where stereoisomers exist, the opposed isomer will be identified by the suffix (E) and the same side isomer will be identified by the suffix (Z). The letters “E” or “Z” are appended at the end of the refrigerant number to show the precedence of the atoms or groups, which are attached to the carbon atoms at either end of the double bond. An example of this system is given in Table 2.6. “E” for Entgegen is similar to trans, where priority atoms or groups are across the double bond from each other. “Z” for Zusammen is similar to cis, signifying that priority atoms or groups are on the same side of a double bond (Figure 2.1).
Table 2.4 List of Hydrofluorocarbon (HFC) refrigerants [8].
| Product R- Number | ODP | GWP | |
| 23 | 0 | Zero | 14800 |
| 32 | 0 | Zero | 675 |
| 134A | 0 | Zero | 1430 |
| 404A | 0 | Zero | 3922 |
| 407A | 0 | Zero | 2107 |
| 407C | 0 | Zero | 1774 |
| 407F | 0 | Zero | 2088 |
| 417A | 0 | Zero | 2346 |
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