R-290 (Propane) PT Chart
A3 GWP 3Propane (C₃H₈). Natural / HC.
About R-290 (Propane)
R-290 (propane) is a natural refrigerant with a GWP of 3, used in self-contained commercial coolers, display cases, ice machines and, increasingly, heat pumps. Its pressures are close to R-22's. It is highly flammable (A3), so charge sizes are capped and technicians need spark-proof tools and hydrocarbon-specific training.
Saturation pressures at typical operating points, taken from the table below:
- Medium-temp evaporator (20°F): 41.1 PSIG
- Condensing (105°F): 186.5 PSIG
The table covers -80°F to 200°F in 5°F steps. Below about -44°F the saturation pressure is below atmospheric, so gauges read in vacuum (shown in blue in the table).
R-290 (Propane) Pressure-Temperature Graph
R-290 (Propane) Saturation Pressure Table
Blue values indicate vacuum (below atmospheric pressure).
| °F | °C | PSIG | PSIA | kPa | bar |
|---|---|---|---|---|---|
| -80 | -62.2 | -9.2 | 5.5 | 37.9 | 0.379 |
| -75 | -59.4 | -8.3 | 6.38 | 44.0 | 0.44 |
| -70 | -56.7 | -7.3 | 7.36 | 50.8 | 0.508 |
| -65 | -53.9 | -6.2 | 8.47 | 58.4 | 0.584 |
| -60 | -51.1 | -5.0 | 9.7 | 66.9 | 0.669 |
| -55 | -48.3 | -3.6 | 11.07 | 76.4 | 0.764 |
| -50 | -45.6 | -2.1 | 12.59 | 86.8 | 0.868 |
| -45 | -42.8 | -0.4 | 14.27 | 98.4 | 0.984 |
| -40 | -40.0 | 1.4 | 16.12 | 111.1 | 1.111 |
| -35 | -37.2 | 3.4 | 18.14 | 125.1 | 1.251 |
| -30 | -34.4 | 5.7 | 20.36 | 140.4 | 1.404 |
| -25 | -31.7 | 8.1 | 22.79 | 157.1 | 1.571 |
| -20 | -28.9 | 10.7 | 25.42 | 175.3 | 1.753 |
| -15 | -26.1 | 13.6 | 28.29 | 195.1 | 1.951 |
| -10 | -23.3 | 16.7 | 31.4 | 216.5 | 2.165 |
| -5 | -20.6 | 20.1 | 34.76 | 239.7 | 2.397 |
| 0 | -17.8 | 23.7 | 38.39 | 264.7 | 2.647 |
| 5 | -15.0 | 27.6 | 42.3 | 291.6 | 2.916 |
| 10 | -12.2 | 31.8 | 46.5 | 320.6 | 3.206 |
| 15 | -9.4 | 36.3 | 51.01 | 351.7 | 3.517 |
| 20 | -6.7 | 41.1 | 55.83 | 385.0 | 3.85 |
| 25 | -3.9 | 46.3 | 61.0 | 420.6 | 4.206 |
| 30 | -1.1 | 51.8 | 66.51 | 458.6 | 4.586 |
| 35 | 1.7 | 57.7 | 72.38 | 499.1 | 4.991 |
| 40 | 4.4 | 63.9 | 78.64 | 542.2 | 5.422 |
| 45 | 7.2 | 70.6 | 85.28 | 588.0 | 5.88 |
| 50 | 10.0 | 77.6 | 92.33 | 636.6 | 6.366 |
| 55 | 12.8 | 85.1 | 99.8 | 688.1 | 6.881 |
| 60 | 15.6 | 93.0 | 107.71 | 742.7 | 7.427 |
| 65 | 18.3 | 101.4 | 116.08 | 800.3 | 8.003 |
| 70 | 21.1 | 110.2 | 124.91 | 861.2 | 8.612 |
| 75 | 23.9 | 119.5 | 134.22 | 925.4 | 9.254 |
| 80 | 26.7 | 129.3 | 144.04 | 993.1 | 9.931 |
| 85 | 29.4 | 139.7 | 154.37 | 1064.3 | 10.643 |
| 90 | 32.2 | 150.5 | 165.23 | 1139.2 | 11.392 |
| 95 | 35.0 | 161.9 | 176.64 | 1217.9 | 12.179 |
| 100 | 37.8 | 173.9 | 188.62 | 1300.5 | 13.005 |
| 105 | 40.6 | 186.5 | 201.18 | 1387.1 | 13.871 |
| 110 | 43.3 | 199.6 | 214.34 | 1477.8 | 14.778 |
| 115 | 46.1 | 213.4 | 228.12 | 1572.8 | 15.728 |
| 120 | 48.9 | 227.8 | 242.54 | 1672.3 | 16.723 |
| 125 | 51.7 | 242.9 | 257.62 | 1776.2 | 17.762 |
| 130 | 54.4 | 258.7 | 273.38 | 1884.9 | 18.849 |
| 135 | 57.2 | 275.1 | 289.83 | 1998.3 | 19.983 |
| 140 | 60.0 | 292.3 | 307.01 | 2116.8 | 21.168 |
| 145 | 62.8 | 310.2 | 324.93 | 2240.3 | 22.403 |
| 150 | 65.6 | 328.9 | 343.62 | 2369.2 | 23.692 |
| 155 | 68.3 | 348.4 | 363.1 | 2503.5 | 25.035 |
| 160 | 71.1 | 368.7 | 383.4 | 2643.4 | 26.434 |
| 165 | 73.9 | 389.9 | 404.55 | 2789.3 | 27.893 |
| 170 | 76.7 | 411.9 | 426.59 | 2941.2 | 29.412 |
| 175 | 79.4 | 434.8 | 449.54 | 3099.5 | 30.995 |
| 180 | 82.2 | 458.8 | 473.45 | 3264.3 | 32.643 |
| 185 | 85.0 | 483.7 | 498.36 | 3436.1 | 34.361 |
| 190 | 87.8 | 509.6 | 524.34 | 3615.2 | 36.152 |
| 195 | 90.6 | 536.8 | 551.45 | 3802.1 | 38.021 |
| 200 | 93.3 | 565.1 | 579.8 | 3997.6 | 39.976 |
Properties
| ASHRAE Designation | 290 |
| Safety Classification | A3 |
| GWP (AR4, 100-yr) | 3 |
| ODP | 0 |
| Molecular Weight | 44.1 g/mol |
| Boiling Point (1 atm) | -43.8°F / -42.1°C |
| Critical Temperature | 206.1°F / 96.7°C |
| Critical Pressure | 616.6 psia / 42.51 bar |
| Category | Natural / HC |
Common Applications
- Small commercial refrigeration
- Heat pumps
- Portable AC
Frequently Asked Questions
What pressure should R-290 (propane) be at 70°F?
At 70°F, R-290 (propane) has a saturation pressure of 110.2 PSIG (124.9 PSIA). Propane has excellent thermodynamic properties and operates at similar pressures to R-22, but requires A3 safety measures.
Is R-290 propane safe to use as a refrigerant?
R-290 is classified A3 (flammable) and requires special equipment design, leak detection, and technician certification. It is widely used in small commercial units (coolers, vending machines) and some residential appliances, with charge sizes limited by safety standards.
What equipment uses R-290 propane refrigerant?
R-290 is used in small commercial reach-in coolers, vending machines, ice cream freezers, and domestic refrigerators (especially in Europe). Charge limits have historically been 150 g per circuit; IEC 60335-2-89 and UL 60335-2-89 now allow up to about 500 g in self-contained commercial units, which still restricts R-290 to relatively small systems.