R-12 PT Chart
A1 GWP 10900Pure refrigerant (Dichlorodifluoromethane / Freon-12). CFC.
⚠️ BANNED — Phased out under Montreal Protocol (1996)
About R-12
R-12 (Freon-12) was the refrigerant in pre-1994 automotive AC, domestic refrigerators and many small commercial systems. As a CFC it was phased out under the Montreal Protocol, with US production ending in 1996, and it survives mainly in classic cars and vintage appliances. R-134a is the usual retrofit, which needs an oil change and new fittings.
Saturation pressures at typical operating points, taken from the table below:
- Evaporator (35°F): 32.5 PSIG
- Condensing (130°F): 180.5 PSIG
The table covers -65°F to 225°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-12 Pressure-Temperature Graph
R-12 Saturation Pressure Table
Blue values indicate vacuum (below atmospheric pressure).
| °F | °C | PSIG | PSIA | kPa | bar |
|---|---|---|---|---|---|
| -65 | -53.9 | -10.1 | 4.62 | 31.8 | 0.318 |
| -60 | -51.1 | -9.3 | 5.35 | 36.9 | 0.369 |
| -55 | -48.3 | -8.5 | 6.18 | 42.6 | 0.426 |
| -50 | -45.6 | -7.6 | 7.11 | 49.0 | 0.49 |
| -45 | -42.8 | -6.6 | 8.14 | 56.1 | 0.561 |
| -40 | -40.0 | -5.4 | 9.3 | 64.1 | 0.641 |
| -35 | -37.2 | -4.1 | 10.57 | 72.9 | 0.729 |
| -30 | -34.4 | -2.7 | 11.98 | 82.6 | 0.826 |
| -25 | -31.7 | -1.2 | 13.54 | 93.3 | 0.933 |
| -20 | -28.9 | 0.5 | 15.24 | 105.1 | 1.051 |
| -15 | -26.1 | 2.4 | 17.11 | 118.0 | 1.18 |
| -10 | -23.3 | 4.5 | 19.16 | 132.1 | 1.321 |
| -5 | -20.6 | 6.7 | 21.39 | 147.5 | 1.475 |
| 0 | -17.8 | 9.1 | 23.81 | 164.2 | 1.642 |
| 5 | -15.0 | 11.7 | 26.44 | 182.3 | 1.823 |
| 10 | -12.2 | 14.6 | 29.29 | 201.9 | 2.019 |
| 15 | -9.4 | 17.7 | 32.37 | 223.2 | 2.232 |
| 20 | -6.7 | 21.0 | 35.68 | 246.0 | 2.46 |
| 25 | -3.9 | 24.6 | 39.25 | 270.6 | 2.706 |
| 30 | -1.1 | 28.4 | 43.08 | 297.0 | 2.97 |
| 35 | 1.7 | 32.5 | 47.19 | 325.4 | 3.254 |
| 40 | 4.4 | 36.9 | 51.59 | 355.7 | 3.557 |
| 45 | 7.2 | 41.6 | 56.29 | 388.1 | 3.881 |
| 50 | 10.0 | 46.6 | 61.3 | 422.7 | 4.227 |
| 55 | 12.8 | 51.9 | 66.64 | 459.5 | 4.595 |
| 60 | 15.6 | 57.6 | 72.32 | 498.7 | 4.987 |
| 65 | 18.3 | 63.7 | 78.36 | 540.3 | 5.403 |
| 70 | 21.1 | 70.1 | 84.76 | 584.4 | 5.844 |
| 75 | 23.9 | 76.8 | 91.54 | 631.1 | 6.311 |
| 80 | 26.7 | 84.0 | 98.71 | 680.6 | 6.806 |
| 85 | 29.4 | 91.6 | 106.29 | 732.9 | 7.329 |
| 90 | 32.2 | 99.6 | 114.29 | 788.0 | 7.88 |
| 95 | 35.0 | 108.0 | 122.73 | 846.2 | 8.462 |
| 100 | 37.8 | 116.9 | 131.62 | 907.5 | 9.075 |
| 105 | 40.6 | 126.3 | 140.97 | 972.0 | 9.72 |
| 110 | 43.3 | 136.1 | 150.81 | 1039.8 | 10.398 |
| 115 | 46.1 | 146.4 | 161.13 | 1111.0 | 11.11 |
| 120 | 48.9 | 157.3 | 171.97 | 1185.7 | 11.857 |
| 125 | 51.7 | 168.6 | 183.33 | 1264.0 | 12.64 |
| 130 | 54.4 | 180.5 | 195.24 | 1346.1 | 13.461 |
| 135 | 57.2 | 193.0 | 207.7 | 1432.1 | 14.321 |
| 140 | 60.0 | 206.0 | 220.74 | 1521.9 | 15.219 |
| 145 | 62.8 | 219.7 | 234.37 | 1615.9 | 16.159 |
| 150 | 65.6 | 233.9 | 248.61 | 1714.1 | 17.141 |
| 155 | 68.3 | 248.8 | 263.47 | 1816.6 | 18.166 |
| 160 | 71.1 | 264.3 | 278.99 | 1923.6 | 19.236 |
| 165 | 73.9 | 280.5 | 295.17 | 2035.1 | 20.351 |
| 170 | 76.7 | 297.3 | 312.04 | 2151.4 | 21.514 |
| 175 | 79.4 | 314.9 | 329.62 | 2272.6 | 22.726 |
| 180 | 82.2 | 333.2 | 347.93 | 2398.9 | 23.989 |
| 185 | 85.0 | 352.3 | 367.0 | 2530.4 | 25.304 |
| 190 | 87.8 | 372.2 | 386.85 | 2667.3 | 26.673 |
| 195 | 90.6 | 392.8 | 407.52 | 2809.8 | 28.098 |
| 200 | 93.3 | 414.3 | 429.04 | 2958.2 | 29.582 |
| 205 | 96.1 | 436.8 | 451.45 | 3112.7 | 31.127 |
| 210 | 98.9 | 460.1 | 474.8 | 3273.6 | 32.736 |
| 215 | 101.7 | 484.4 | 499.13 | 3441.4 | 34.414 |
| 220 | 104.4 | 509.8 | 524.53 | 3616.5 | 36.165 |
| 225 | 107.2 | 536.4 | 551.11 | 3799.8 | 37.998 |
Properties
| ASHRAE Designation | 12 |
| Safety Classification | A1 (non-flammable, low toxicity) |
| GWP (AR4, 100-yr) | 10900 |
| ODP | 1.0 |
| Molecular Weight | 120.91 g/mol |
| Boiling Point (1 atm) | -21.6°F / -29.8°C |
| Critical Temperature | 233.5°F / 112°C |
| Critical Pressure | 599.9 psia / 41.36 bar |
| Category | CFC |
Common Applications
- Legacy automotive AC
- Legacy refrigeration