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.
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.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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