R-22 pressure-temperature chart
R-22 saturation pressures from -40 °F to 150 °F, in gauge pressure (psig). Enter any temperature or pressure in the tool above to get the other, corrected for your elevation. At 40 °F, R-22 saturates at 68.6 psig; at 105 °F, 210.8 psig.
R-22 PT chart (psig, every 5 °F)
| °F | °C | Pressure psig |
|---|---|---|
| -40 | -40.0 | 0.6 |
| -35 | -37.2 | 2.6 |
| -30 | -34.4 | 4.9 |
| -25 | -31.7 | 7.4 |
| -20 | -28.9 | 10.2 |
| -15 | -26.1 | 13.2 |
| -10 | -23.3 | 16.5 |
| -5 | -20.6 | 20.1 |
| 0 | -17.8 | 24.0 |
| 5 | -15.0 | 28.3 |
| 10 | -12.2 | 32.8 |
| 15 | -9.4 | 37.8 |
| 20 | -6.7 | 43.1 |
| 25 | -3.9 | 48.8 |
| 30 | -1.1 | 55.0 |
| 35 | 1.7 | 61.5 |
| 40 | 4.4 | 68.6 |
| 45 | 7.2 | 76.1 |
| 50 | 10.0 | 84.1 |
| 55 | 12.8 | 92.6 |
| 60 | 15.6 | 101.6 |
| 65 | 18.3 | 111.2 |
| 70 | 21.1 | 121.4 |
| 75 | 23.9 | 132.2 |
| 80 | 26.7 | 143.6 |
| 85 | 29.4 | 155.7 |
| 90 | 32.2 | 168.4 |
| 95 | 35.0 | 181.8 |
| 100 | 37.8 | 195.9 |
| 105 | 40.6 | 210.8 |
| 110 | 43.3 | 226.4 |
| 115 | 46.1 | 242.8 |
| 120 | 48.9 | 260.0 |
| 125 | 51.7 | 278.0 |
| 130 | 54.4 | 296.9 |
| 135 | 57.2 | 316.7 |
| 140 | 60.0 | 337.4 |
| 145 | 62.8 | 359.0 |
| 150 | 65.6 | 381.7 |
Need a reading between rows, or your elevation corrected? Use the tool above: type a temperature or a pressure and it fills in the other.
About R-22
R-22 is a single-component HCFC refrigerant that was the standard in US air conditioning before R-410A. It is ozone-depleting, so its production and import ended in the US on January 1, 2020. Existing R-22 systems can still be serviced, but only with recovered, recycled or reclaimed R-22 or stock produced before 2020, which is why it is expensive.
Because R-22 is a single component, liquid and vapor saturate at the same temperature and the chart has one pressure column.
How to read a PT chart
A pressure-temperature chart gives the saturation temperature: the temperature at which the refrigerant boils or condenses at a given pressure. Inside the evaporator and condenser, where liquid and vapor are both present, pressure and temperature are locked together, so one gauge reading tells you the other.
- Find your pressure on the chart (or type it into the tool) and read the saturation temperature next to it.
- Superheat = suction line temperature − saturation temperature at suction pressure. Use the superheat calculator.
- Subcooling = saturation temperature at liquid line pressure − liquid line temperature. Use the subcooling calculator.
- Gauges read psig, pressure above the air around you. Charts are built for sea level (14.696 psi). At 5,000 ft your gauge reads about 2.5 psi high against the chart; enter your elevation in the tool and it corrects for it.
Working on refrigerant circuits?
Opening the refrigerant circuit on stationary equipment using the refrigerants on this page requires EPA Section 608 certification, and suppliers can only sell you most refrigerants if you have it. See how to get EPA 608 certified or take the free EPA 608 practice tests.
Where the numbers come from
Saturation pressures for R-22: NIST Chemistry WebBook (NIST Standard Reference Database 69). Converted to gauge pressure at sea level (psig = psia − 14.696); below 0 psig the chart shows inches of mercury of vacuum. Values are for pure refrigerant: air, moisture or a mixed charge will throw readings off. The equipment manufacturer's charging chart and data plate govern.
FAQ
What should R-22 pressures be?
On a typical cooling day the evaporator runs near 40 °F saturation, about 69 psig on the suction side, and the condenser 15 to 30 °F above outdoor air, roughly 211 psig at 105 °F. Judge the charge by superheat or subcooling, not pressure alone.
What is R-22 pressure at 40 degrees?
68.6 psig at sea level.
Can I still buy R-22?
Only reclaimed R-22 (from an EPA-certified reclaimer) or R-22 produced before 2020, and only with EPA Section 608 certification, because production and import ended in 2020. Many owners replace the system instead of recharging a leaking one.
Is this tool free?
Yes. No account, no email, no download. It runs in your browser and works on your phone at the unit.