R-717 (Ammonia) PT Chart
B2L GWP 0Ammonia (NH₃). Natural.
About R-717 (Ammonia)
R-717 (ammonia) is the dominant refrigerant in industrial refrigeration, including cold storage, food and beverage processing, and ice rinks. It has excellent efficiency and zero GWP and ODP, but it is toxic (B2L) and incompatible with copper, so systems use steel piping and fall under IIAR and OSHA process-safety rules.
Saturation pressures at typical operating points, taken from the table below:
- Freezer evaporator (−20°F): 3.6 PSIG
- Medium-temp evaporator (20°F): 33.5 PSIG
- Condensing (105°F): 214.3 PSIG
The table covers -70°F to 265°F in 5°F steps. Below about -28°F the saturation pressure is below atmospheric, so gauges read in vacuum (shown in blue in the table).
R-717 (Ammonia) Pressure-Temperature Graph
R-717 (Ammonia) Saturation Pressure Table
Blue values indicate vacuum (below atmospheric pressure).
| °F | °C | PSIG | PSIA | kPa | bar |
|---|---|---|---|---|---|
| -70 | -56.7 | -10.8 | 3.93 | 27.1 | 0.271 |
| -65 | -53.9 | -10.0 | 4.68 | 32.2 | 0.322 |
| -60 | -51.1 | -9.2 | 5.54 | 38.2 | 0.382 |
| -55 | -48.3 | -8.2 | 6.52 | 45.0 | 0.45 |
| -50 | -45.6 | -7.0 | 7.65 | 52.7 | 0.527 |
| -45 | -42.8 | -5.8 | 8.93 | 61.6 | 0.616 |
| -40 | -40.0 | -4.3 | 10.39 | 71.6 | 0.716 |
| -35 | -37.2 | -2.7 | 12.03 | 83.0 | 0.83 |
| -30 | -34.4 | -0.8 | 13.88 | 95.7 | 0.957 |
| -25 | -31.7 | 1.3 | 15.95 | 110.0 | 1.1 |
| -20 | -28.9 | 3.6 | 18.27 | 126.0 | 1.26 |
| -15 | -26.1 | 6.2 | 20.85 | 143.8 | 1.438 |
| -10 | -23.3 | 9.0 | 23.72 | 163.5 | 1.635 |
| -5 | -20.6 | 12.2 | 26.89 | 185.4 | 1.854 |
| 0 | -17.8 | 15.7 | 30.39 | 209.5 | 2.095 |
| 5 | -15.0 | 19.5 | 34.24 | 236.1 | 2.361 |
| 10 | -12.2 | 23.8 | 38.48 | 265.3 | 2.653 |
| 15 | -9.4 | 28.4 | 43.11 | 297.3 | 2.973 |
| 20 | -6.7 | 33.5 | 48.18 | 332.2 | 3.322 |
| 25 | -3.9 | 39.0 | 53.7 | 370.3 | 3.703 |
| 30 | -1.1 | 45.0 | 59.71 | 411.7 | 4.117 |
| 35 | 1.7 | 51.5 | 66.23 | 456.7 | 4.567 |
| 40 | 4.4 | 58.6 | 73.3 | 505.4 | 5.054 |
| 45 | 7.2 | 66.2 | 80.93 | 558.0 | 5.58 |
| 50 | 10.0 | 74.5 | 89.17 | 614.8 | 6.148 |
| 55 | 12.8 | 83.3 | 98.04 | 676.0 | 6.76 |
| 60 | 15.6 | 92.9 | 107.58 | 741.7 | 7.417 |
| 65 | 18.3 | 103.1 | 117.81 | 812.3 | 8.123 |
| 70 | 21.1 | 114.1 | 128.78 | 887.9 | 8.879 |
| 75 | 23.9 | 125.8 | 140.51 | 968.8 | 9.688 |
| 80 | 26.7 | 138.4 | 153.05 | 1055.2 | 10.552 |
| 85 | 29.4 | 151.7 | 166.41 | 1147.4 | 11.474 |
| 90 | 32.2 | 166.0 | 180.65 | 1245.6 | 12.456 |
| 95 | 35.0 | 181.1 | 195.8 | 1350.0 | 13.5 |
| 100 | 37.8 | 197.2 | 211.89 | 1460.9 | 14.609 |
| 105 | 40.6 | 214.3 | 228.96 | 1578.6 | 15.786 |
| 110 | 43.3 | 232.4 | 247.05 | 1703.4 | 17.034 |
| 115 | 46.1 | 251.5 | 266.2 | 1835.4 | 18.354 |
| 120 | 48.9 | 271.7 | 286.44 | 1975.0 | 19.75 |
| 125 | 51.7 | 293.1 | 307.83 | 2122.4 | 21.224 |
| 130 | 54.4 | 315.7 | 330.38 | 2277.9 | 22.779 |
| 135 | 57.2 | 339.5 | 354.16 | 2441.9 | 24.419 |
| 140 | 60.0 | 364.5 | 379.2 | 2614.5 | 26.145 |
| 145 | 62.8 | 390.8 | 405.54 | 2796.1 | 27.961 |
| 150 | 65.6 | 418.5 | 433.23 | 2987.0 | 29.87 |
| 155 | 68.3 | 447.6 | 462.3 | 3187.5 | 31.875 |
| 160 | 71.1 | 478.1 | 492.82 | 3397.9 | 33.979 |
| 165 | 73.9 | 510.1 | 524.81 | 3618.4 | 36.184 |
| 170 | 76.7 | 543.6 | 558.33 | 3849.6 | 38.496 |
| 175 | 79.4 | 578.7 | 593.43 | 4091.6 | 40.916 |
| 180 | 82.2 | 615.5 | 630.16 | 4344.8 | 43.448 |
| 185 | 85.0 | 653.9 | 668.56 | 4609.5 | 46.095 |
| 190 | 87.8 | 694.0 | 708.69 | 4886.2 | 48.862 |
| 195 | 90.6 | 735.9 | 750.6 | 5175.2 | 51.752 |
| 200 | 93.3 | 779.7 | 794.36 | 5476.9 | 54.769 |
| 205 | 96.1 | 825.3 | 840.01 | 5791.7 | 57.917 |
| 210 | 98.9 | 872.9 | 887.62 | 6119.9 | 61.199 |
| 215 | 101.7 | 922.6 | 937.26 | 6462.2 | 64.622 |
| 220 | 104.4 | 974.3 | 988.99 | 6818.8 | 68.188 |
| 225 | 107.2 | 1028.2 | 1042.88 | 7190.4 | 71.904 |
| 230 | 110.0 | 1084.3 | 1099.02 | 7577.5 | 75.775 |
| 235 | 112.8 | 1142.8 | 1157.49 | 7980.6 | 79.806 |
| 240 | 115.6 | 1203.7 | 1218.38 | 8400.4 | 84.004 |
| 245 | 118.3 | 1267.1 | 1281.8 | 8837.7 | 88.377 |
| 250 | 121.1 | 1333.2 | 1347.88 | 9293.3 | 92.933 |
| 255 | 123.9 | 1402.1 | 1416.76 | 9768.2 | 97.682 |
| 260 | 126.7 | 1473.9 | 1488.63 | 10263.7 | 102.637 |
| 265 | 129.4 | 1549.1 | 1563.77 | 10781.8 | 107.818 |
Properties
| ASHRAE Designation | 717 |
| Safety Classification | B2L (mildly flammable) |
| GWP (AR4, 100-yr) | 0 |
| ODP | 0 |
| Molecular Weight | 17.03 g/mol |
| Boiling Point (1 atm) | -28°F / -33.3°C |
| Critical Temperature | 270.3°F / 132.4°C |
| Critical Pressure | 1648.1 psia / 113.63 bar |
| Category | Natural |
Common Applications
- Industrial refrigeration
- Cold storage
- Ice rinks
Frequently Asked Questions
What pressure should R-717 (ammonia) be at 70°F?
At 70°F, R-717 (ammonia) has a saturation pressure of 114.1 PSIG (128.8 PSIA). Ammonia operates at moderate pressures similar to R-22, with excellent thermodynamic efficiency and zero GWP.
Is ammonia dangerous as a refrigerant?
R-717 (ammonia) is classified B2L — toxic with low flammability. Ammonia has a strong odor detectable at 5 ppm (well below hazardous levels), acts as its own leak detector. Industrial systems require trained operators, secondary containment, and gas detection.
Where is ammonia used as a refrigerant?
R-717 is the dominant refrigerant in large industrial cold storage, food processing, ice rinks, and district cooling. Its high efficiency and zero GWP make it the preferred choice where scale and operator expertise are available.