A non-ozone depleting azeotrope of R-23 and FC-116 used to replace R-13 and R-503 in the low stage of cascade systems. For new equipment and retrofits.
508B
General Information
| Item | Specification |
|---|---|
| ASHRAE # | R-508B |
| Class | HFC |
| Refrigerant Type | Azeotrope |
| Typical Lubricant | POE |
| Substitutes | CFC-13 / R-503 |
| Contains | HFC-23 (46%), FC-116 (54%) |
| Notes | Lower discharge temperatures than R-13 and R-23. Good performance match to R-503. |
Physical Properties
| Property | Value |
|---|---|
| Chemical Name | Trifluoromethane, Hexafluoroethane |
| Chemical Notation | CHF3, C2 F6 |
| Molecular Weight | 95.4 |
| Boiling Point (°C) | -87.4 |
| Freezing Point (°C) | -17.8 |
| Critical Temperature (°C) | 11.2 |
| Critical Pressure (bar) | 37.72 |
| Liquid Density (kg/m³) 0°C | 969.5 |
| Specific Heat of Liquid @ Constant Pressure @ 25°C (kJ/(kg.K)) | NA |
| Specific Heat of Vapor @ Constant Pressure @ 25°C (kJ/(kg.K)) | NA |
| Vapour Density (kg/m³) 25°C | 3.9 |
| GWP | 13396 |
| ODP | Non-ozone depleting |
| ATEL/ODL (kg/m³) | 0.2 |
| Practical Limit (kg/m³) | 0.25 |
| AIT (°C) | ND |
| Flammable range, %vol. in air (Based on ASHRAE Standard 34 with Match Ignition) | None |
| ANSIASHRAE Standard 36-1992 Safety Group Classification | A1 |