R-404A PT chart
Saturation pressures for R-404A from -40 °F to 150 °F (-40 °C to 65.6 °C), computed from reference equations of state[7]. R-404A is near-azeotropic. Its temperature glide is under 1 °F, so the liquid and vapor columns sit close together.
| Temp (°F) | Liquid / bubble (psig) | Vapor / dew (psig) |
|---|---|---|
| -40 | 4.9 | 4.3 |
| -35 | 7.5 | 6.8 |
| -30 | 10.3 | 9.6 |
| -25 | 13.4 | 12.7 |
| -20 | 16.8 | 16.0 |
| -15 | 20.5 | 19.7 |
| -10 | 24.6 | 23.6 |
| -5 | 28.9 | 27.9 |
| 0 | 33.7 | 32.6 |
| 5 | 38.8 | 37.7 |
| 10 | 44.3 | 43.1 |
| 15 | 50.2 | 49.0 |
| 20 | 56.6 | 55.3 |
| 25 | 63.4 | 62.1 |
| 30 | 70.7 | 69.3 |
| 35 | 78.6 | 77.1 |
| 40 | 86.9 | 85.4 |
| 45 | 95.8 | 94.2 |
| 50 | 105.3 | 103.6 |
| 55 | 115.3 | 113.6 |
| 60 | 126.0 | 124.2 |
| 65 | 137.3 | 135.5 |
| 70 | 149.3 | 147.4 |
| 75 | 162.0 | 160.1 |
| 80 | 175.4 | 173.4 |
| 85 | 189.5 | 187.5 |
| 90 | 204.5 | 202.4 |
| 95 | 220.2 | 218.1 |
| 100 | 236.8 | 234.6 |
| 105 | 254.2 | 252.0 |
| 110 | 272.5 | 270.4 |
| 115 | 291.8 | 289.6 |
| 120 | 312.0 | 309.9 |
| 125 | 333.3 | 331.2 |
| 130 | 355.6 | 353.5 |
| 135 | 379.1 | 377.0 |
| 140 | 403.7 | 401.7 |
| 145 | 429.6 | 427.7 |
| 150 | 456.8 | 455.1 |
Use the vapor (dew) column to check superheat at the suction line. Use the liquid (bubble) column to check subcooling at the liquid line and for charging. R-404A glide is under 1 °F. Either column works for field checks. R-404A values are computed, not transcribed; see Sources.
How to read it: measure suction pressure at the service port, find that pressure in the vapor column, and the temperature beside it is the saturation temperature. Suction line temperature minus saturation temperature is superheat. For subcooling, use the liquid column and liquid line pressure, then subtract the liquid line temperature from the saturation temperature.
About this data
Computed with CoolProp 8.0.0 predefined mixture models (Helmholtz-energy equations of state; Bell, Wronski, Quoilin, Lemort 2014, Ind. Eng. Chem. Res. 53(6), doi:10.1021/ie4033999).
Full R-404A reference: regulatory status, replacements, and equipment rated for it, on the R-404A page.
Updated