Refrigerant · HFC

R-134a pressure-temperature chart and data

Tetrafluoroethane. Safety class A1, GWP 1,430. Medium-temperature refrigeration, fridges, chillers and car A/C. Replaced R-12.

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R-134a data sheet

NameTetrafluoroethane
TypeHFC
Safety classA1 — lower toxicity, does not burn
Ozone depletion (ODP)0
Global warming (GWP, 100 yr)1,430
Boils at 1 atm-14.9 °F (-26.1 °C)
Critical temperature213.9 °F (101.1 °C)
Temperature glidenone / very small
Low side at 5 °F evaporating9.1 psig (63 kPa)
High side at 86 °F condensing97.0 psig (669 kPa)
Old cylinder colourLight blue
OilPOE (PAG in car A/C)
Used forMedium-temperature refrigeration, fridges, chillers and car A/C. Replaced R-12.

Pressures are saturation values from reference equations of state. Real pressures change with load and airflow. GWP is the IPCC AR4 100-year value (blends calculated from their ingredients). Cylinder colours were an old AHRI code; since 2020 new cylinders are all one colour with the name on the label, so always read the label, never go by colour.

R-134a pressure / temperature chart

°F°CpsigkPa
-60-51.1V 21.8-74
-59-50.6V 21.5-73
-58-50.0V 21.2-72
-57-49.4V 20.9-71
-56-48.9V 20.6-70
-55-48.3V 20.3-69
-54-47.8V 20.0-68
-53-47.2V 19.7-67
-52-46.7V 19.4-66
-51-46.1V 19.1-65
-50-45.6V 18.7-63
-49-45.0V 18.4-62
-48-44.4V 18.0-61
-47-43.9V 17.7-60
-46-43.3V 17.3-58
-45-42.8V 16.9-57
-44-42.2V 16.5-56
-43-41.7V 16.1-54
-42-41.1V 15.7-53
-41-40.6V 15.2-52
-40-40.0V 14.8-50
-39-39.4V 14.4-49
-38-38.9V 13.9-47
-37-38.3V 13.4-46
-36-37.8V 12.9-44
-35-37.2V 12.5-42
-34-36.7V 12.0-40
-33-36.1V 11.4-39
-32-35.6V 10.9-37
-31-35.0V 10.4-35
-30-34.4V 9.8-33
-29-33.9V 9.3-31
-28-33.3V 8.7-30
-27-32.8V 8.1-28
-26-32.2V 7.5-26
-25-31.7V 6.9-23
-24-31.1V 6.3-21
-23-30.6V 5.7-19
-22-30.0V 5.0-17
-21-29.4V 4.3-15
-20-28.9V 3.7-12
-19-28.3V 3.0-10
-18-27.8V 2.3-8
-17-27.2V 1.5-5
-16-26.7V 0.8-3
-15-26.1V 0.0-0
-14-25.60.32
-13-25.00.75
-12-24.41.18
-11-23.91.511
-10-23.31.913
-9-22.82.416
-8-22.22.819
-7-21.73.222
-6-21.13.625
-5-20.64.128
-4-20.04.631
-3-19.45.035
-2-18.95.538
-1-18.36.041
0-17.86.545
1-17.27.048
2-16.77.552
3-16.18.055
4-15.68.559
5-15.09.163
6-14.49.666
7-13.910.270
8-13.310.874
9-12.811.378
10-12.211.982
11-11.712.586
12-11.113.191
13-10.613.895
14-10.014.499
15-9.415.0104
16-8.915.7108
17-8.316.4113
18-7.817.0117
19-7.217.7122
20-6.718.4127
21-6.119.1132
22-5.619.9137
23-5.020.6142
24-4.421.4147
25-3.922.1152
26-3.322.9158
27-2.823.7163
28-2.224.5169
29-1.725.3174
30-1.126.1180
31-0.626.9186
320.027.8191
330.628.6197
341.129.5203
351.730.4210
362.231.3216
372.832.2222
383.333.1228
393.934.1235
404.435.0242
415.036.0248
425.637.0255
436.138.0262
446.739.0269
457.240.0276
467.841.1283
478.342.2291
488.943.2298
499.444.3306
5010.045.4313
5110.646.6321
5211.147.7329
5311.748.9337
5412.250.0345
5512.851.2353
5613.352.4361
5713.953.6370
5814.454.9378
5915.056.1387
6015.657.4396
6116.158.7405
6216.760.0414
6317.261.3423
6417.862.7432
6518.364.0441
6618.965.4451
6719.466.8461
6820.068.2470
6920.669.7480
7021.171.1490
7121.772.6500
7222.274.1511
7322.875.6521
7423.377.1532
7523.978.7542
7624.480.2553
7725.081.8564
7825.683.4575
7926.185.0586
8026.786.7598
8127.288.4609
8227.890.0621
8328.391.8633
8428.993.5645
8529.495.2657
8630.097.0669
8730.698.8681
8831.1101694
8931.7102706
9032.2104719
9132.8106732
9233.3108745
9333.9110759
9434.4112772
9535.0114786
9635.6116799
9736.1118813
9836.7120827
9937.2122842
10037.8124856
10138.3126871
10238.9128885
10339.4131900
10440.0133915
10540.6135931
10641.1137946
10741.7139961
10842.2142977
10942.8144993
11043.31461009
11143.91491026
11244.41511042
11345.01541059
11445.61561075
11546.11581092
11646.71611110
11747.21631127
11847.81661145
11948.31691162
12048.91711180
12149.41741198
12250.01761217
12350.61791235
12451.11821254
12551.71851273
12652.21871292
12752.81901311
12853.31931331
12953.91961350
13054.41991370

V = vacuum in inches of mercury. Saturation pressure in psig at sea level, calculated from reference equations of state. The chart gives the boiling temperature at that pressure, not the pipe temperature. Air in the system adds pressure and throws it off.

R-134a pressure in psig, psia, kPa and bar

°F°CpsigpsiakPa gaugekPa absolutebar absolute
-60-51.1V 21.84.0-74280.28
-55-48.3V 20.34.7-69320.32
-50-45.6V 18.75.5-63380.38
-45-42.8V 16.96.4-57440.44
-40-40.0V 14.87.4-50510.51
-35-37.2V 12.58.6-42590.59
-30-34.4V 9.89.9-33680.68
-25-31.7V 6.911.3-23780.78
-20-28.9V 3.712.9-12890.89
-15-26.1V 0.014.7-01011.01
-10-23.31.916.6131151.15
-5-20.64.118.8281301.30
0-17.86.521.2451461.46
5-15.09.123.8631641.64
10-12.211.926.6821841.84
15-9.415.029.71042052.05
20-6.718.433.11272282.28
25-3.922.136.81522542.54
30-1.126.140.81802812.81
351.730.445.12103113.11
404.435.049.72423433.43
457.240.054.72763773.77
5010.045.460.13134154.15
5512.851.265.93534544.54
6015.657.472.13964974.97
6518.364.078.74415435.43
7021.171.185.84905925.92
7523.978.793.35426446.44
8026.786.7101.45986996.99
8529.495.2109.96577587.58
9032.2104119.07198218.21
9535.0114128.67868878.87
10037.8124138.98569579.57
10540.6135149.7931103210.32
11043.3146161.11009111111.11
11546.1158173.11092119411.94
12048.9171185.91180128212.82
12551.7185199.31273137413.74
13054.4199213.41370147114.71

V = vacuum in inches of mercury. Absolute pressure = gauge + 14.7 psi at sea level; use absolute pressure for gas-law work. For blends the dew column is the vapour (suction) side and the bubble column the liquid side.

Other refrigerants

R-11 R-12 R-22 R-23 R-32 R-123 R-125 R-143a R-152a R-170 R-245fa R-290 R-401A R-401B R-404A R-407A R-407C R-407F R-408A R-409A R-410A R-417A R-422A R-422D R-427A R-448A R-449A R-450A R-452A R-452B R-454A R-454B R-454C R-455A R-500 R-502 R-507A R-508B R-513A R-600 R-600a R-717 R-744 R-1233zd(E) R-1234yf R-1234ze(E) R-1270

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Calculation aids and reference figures for licensed technicians. Always follow the manufacturer’s data plate and manual for the exact model, and local codes. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Pressures are typical saturation values and change with load and airflow.