R-1234yf PT Chart
A2L GWP 4Pure refrigerant (2,3,3,3-Tetrafluoropropene). HFO.
About R-1234yf
R-1234yf is the HFO that replaced R-134a in new passenger vehicles. Its pressures are within a few PSI of R-134a across the normal operating range, which let automakers keep similar system designs. It is classified A2L, uses a different service port than R-134a to prevent cross-contamination, and needs certified recovery/recharge equipment (SAE J2843).
Saturation pressures at typical operating points, taken from the table below:
- Evaporator (35°F): 33.8 PSIG
- Condensing (130°F): 195.0 PSIG
The table covers -65°F to 195°F in 5°F steps. Below about -21°F the saturation pressure is below atmospheric, so gauges read in vacuum (shown in blue in the table).
R-1234yf Pressure-Temperature Graph
R-1234yf Saturation Pressure Table
Blue values indicate vacuum (below atmospheric pressure).
| °F | °C | PSIG | PSIA | kPa | bar |
|---|---|---|---|---|---|
| -65 | -53.9 | -10.3 | 4.39 | 30.2 | 0.302 |
| -60 | -51.1 | -9.6 | 5.11 | 35.2 | 0.352 |
| -55 | -48.3 | -8.8 | 5.93 | 40.9 | 0.409 |
| -50 | -45.6 | -7.8 | 6.85 | 47.3 | 0.473 |
| -45 | -42.8 | -6.8 | 7.89 | 54.4 | 0.544 |
| -40 | -40.0 | -5.7 | 9.05 | 62.4 | 0.624 |
| -35 | -37.2 | -4.4 | 10.33 | 71.2 | 0.712 |
| -30 | -34.4 | -2.9 | 11.76 | 81.1 | 0.811 |
| -25 | -31.7 | -1.4 | 13.34 | 92.0 | 0.92 |
| -20 | -28.9 | 0.4 | 15.08 | 104.0 | 1.04 |
| -15 | -26.1 | 2.3 | 17.0 | 117.2 | 1.172 |
| -10 | -23.3 | 4.4 | 19.1 | 131.7 | 1.317 |
| -5 | -20.6 | 6.7 | 21.4 | 147.6 | 1.476 |
| 0 | -17.8 | 9.2 | 23.91 | 164.9 | 1.649 |
| 5 | -15.0 | 12.0 | 26.65 | 183.7 | 1.837 |
| 10 | -12.2 | 14.9 | 29.61 | 204.2 | 2.042 |
| 15 | -9.4 | 18.1 | 32.83 | 226.4 | 2.264 |
| 20 | -6.7 | 21.6 | 36.31 | 250.3 | 2.503 |
| 25 | -3.9 | 25.4 | 40.06 | 276.2 | 2.762 |
| 30 | -1.1 | 29.4 | 44.1 | 304.1 | 3.041 |
| 35 | 1.7 | 33.8 | 48.45 | 334.1 | 3.341 |
| 40 | 4.4 | 38.4 | 53.12 | 366.2 | 3.662 |
| 45 | 7.2 | 43.4 | 58.11 | 400.7 | 4.007 |
| 50 | 10.0 | 48.8 | 63.46 | 437.5 | 4.375 |
| 55 | 12.8 | 54.5 | 69.17 | 476.9 | 4.769 |
| 60 | 15.6 | 60.6 | 75.25 | 518.9 | 5.189 |
| 65 | 18.3 | 67.0 | 81.74 | 563.6 | 5.636 |
| 70 | 21.1 | 73.9 | 88.63 | 611.1 | 6.111 |
| 75 | 23.9 | 81.3 | 95.95 | 661.5 | 6.615 |
| 80 | 26.7 | 89.0 | 103.71 | 715.1 | 7.151 |
| 85 | 29.4 | 97.2 | 111.94 | 771.8 | 7.718 |
| 90 | 32.2 | 105.9 | 120.64 | 831.8 | 8.318 |
| 95 | 35.0 | 115.1 | 129.84 | 895.2 | 8.952 |
| 100 | 37.8 | 124.9 | 139.55 | 962.2 | 9.622 |
| 105 | 40.6 | 135.1 | 149.8 | 1032.8 | 10.328 |
| 110 | 43.3 | 145.9 | 160.6 | 1107.3 | 11.073 |
| 115 | 46.1 | 157.3 | 171.97 | 1185.7 | 11.857 |
| 120 | 48.9 | 169.2 | 183.93 | 1268.2 | 12.682 |
| 125 | 51.7 | 181.8 | 196.51 | 1354.9 | 13.549 |
| 130 | 54.4 | 195.0 | 209.72 | 1446.0 | 14.46 |
| 135 | 57.2 | 208.9 | 223.59 | 1541.6 | 15.416 |
| 140 | 60.0 | 223.4 | 238.13 | 1641.9 | 16.419 |
| 145 | 62.8 | 238.7 | 253.39 | 1747.1 | 17.471 |
| 150 | 65.6 | 254.7 | 269.37 | 1857.3 | 18.573 |
| 155 | 68.3 | 271.4 | 286.11 | 1972.7 | 19.727 |
| 160 | 71.1 | 288.9 | 303.64 | 2093.5 | 20.935 |
| 165 | 73.9 | 307.3 | 321.99 | 2220.0 | 22.2 |
| 170 | 76.7 | 326.5 | 341.19 | 2352.4 | 23.524 |
| 175 | 79.4 | 346.6 | 361.28 | 2491.0 | 24.91 |
| 180 | 82.2 | 367.6 | 382.32 | 2636.0 | 26.36 |
| 185 | 85.0 | 389.7 | 404.35 | 2787.9 | 27.879 |
| 190 | 87.8 | 412.8 | 427.45 | 2947.2 | 29.472 |
| 195 | 90.6 | 437.0 | 451.72 | 3114.5 | 31.145 |
Properties
| ASHRAE Designation | 1234yf |
| Safety Classification | A2L (mildly flammable) |
| GWP (AR4, 100-yr) | 4 |
| ODP | 0 |
| Molecular Weight | 114.04 g/mol |
| Boiling Point (1 atm) | -21.1°F / -29.5°C |
| Critical Temperature | 202.5°F / 94.7°C |
| Critical Pressure | 490.6 psia / 33.82 bar |
| Category | HFO |
Common Applications
- Automotive AC (new vehicles)
- R-134a replacement
Frequently Asked Questions
What pressure should R-1234yf be at 70°F?
At 70°F, R-1234yf has a saturation pressure of 73.9 PSIG (88.6 PSIA). This is very close to R-134a (71.1 PSIG), so automotive AC system pressures look similar between old and new vehicles.
What cars use R-1234yf refrigerant?
Most new US passenger vehicles manufactured after approximately 2021 use R-1234yf. It has been standard in European vehicles since 2017. Check the underhood refrigerant label — it will specify R-1234yf or R-134a.
Can I put R-134a in an R-1234yf AC system?
No. R-1234yf and R-134a systems use different service ports (to prevent cross-contamination) and require different PAG oils. Using the wrong refrigerant can damage the compressor. Always use the refrigerant specified on the vehicle's underhood label.