Refrigerant Pressure-Temperature Converter
Look up refrigerant pressure-temperature relationships for R-22, R-410A, and R-134a.
Essential for HVAC diagnostics and charging.
Select a refrigerant and enter a temperature or pressure — the other calculates from the PT chart.
Saturated Conditions
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Refrigerant pressure and temperature have a direct relationship: at a given pressure, a refrigerant boils (or condenses) at a specific temperature. This relationship is essential for HVAC technicians to diagnose system performance and charge systems correctly.
Common refrigerants:
- R-22 (Freon): Older residential AC systems. Being phased out due to ozone depletion. No longer manufactured, only recycled supplies available.
- R-410A (Puron): The standard replacement for R-22 in new residential systems since 2010. Operates at significantly higher pressures than R-22.
- R-134a: Used primarily in automotive air conditioning and small commercial refrigeration. Also common in household refrigerators.
R-22 Pressure-Temperature Chart (saturated):
| Temp (F) | Temp (C) | Pressure (psig) |
|---|---|---|
| 0 | -18 | 24.0 |
| 20 | -7 | 43.0 |
| 40 | 4 | 68.5 |
| 60 | 16 | 101.6 |
| 80 | 27 | 143.6 |
| 100 | 38 | 195.9 |
| 120 | 49 | 260.0 |
R-410A Pressure-Temperature Chart (saturated):
| Temp (F) | Temp (C) | Pressure (psig) |
|---|---|---|
| 0 | -18 | 48.0 |
| 20 | -7 | 80.2 |
| 40 | 4 | 121.4 |
| 60 | 16 | 172.8 |
| 80 | 27 | 236.4 |
| 100 | 38 | 314.2 |
| 120 | 49 | 408.5 |
R-134a Pressure-Temperature Chart (saturated):
| Temp (F) | Temp (C) | Pressure (psig) |
|---|---|---|
| 0 | -18 | 7.4 |
| 20 | -7 | 18.4 |
| 40 | 4 | 34.9 |
| 60 | 16 | 57.0 |
| 80 | 27 | 86.1 |
| 100 | 38 | 123.0 |
| 120 | 49 | 169.0 |
Key diagnostic concepts:
- Superheat: The temperature above the saturated boiling point at the suction line. Normal range is 10-20F (5-11C). Too high means not enough refrigerant; too low means too much.
- Subcooling: The temperature below the saturated condensing point at the liquid line. Normal range is 10-15F (5-8C).
- Measuring both superheat and subcooling helps determine whether a system is properly charged.
Important safety notes:
- R-410A operates at approximately 1.6 times the pressure of R-22. Never use R-22 equipment for R-410A.
- All refrigerants must be recovered and recycled by EPA-certified technicians. Venting refrigerant is illegal in most countries.
- Always wear safety glasses and gloves when working with refrigerants, as they can cause frostbite on contact.