R-134a (HFC)
R-134a PT Chart
The full R-134a pressure-temperature reference table, from -15 to 120°F. R-134a is a pure single-component refrigerant, so the chart is one saturation column with zero glide. Checked cell by cell against one other published table, not a separate publisher: CoolProp. A separate publisher catches a transcription, edition or rounding error; a cross-check that resolves to the same equation of state is a consistency check rather than independent confirmation, and this page says which is which.
R-134a Pressure-Temperature Table
| R-134a | |
|---|---|
| Pressure (psig) | Sat. Temp (°F) |
| 0 | -15°F |
| 2 | -10°F |
| 4 | -5°F |
| 7 | 0°F |
| 9 | 5°F |
| 12 | 10°F |
| 15 | 15°F |
| 18 | 20°F |
| 22 | 25°F |
| 26 | 30°F |
| 30 | 35°F |
| 35 | 40°F |
| 40 | 45°F |
| 45 | 50°F |
| 51 | 55°F |
| 57 | 60°F |
| 64 | 65°F |
| 71 | 70°F |
| 79 | 75°F |
| 87 | 80°F |
| 95 | 85°F |
| 104 | 90°F |
| 114 | 95°F |
| 124 | 100°F |
| 135 | 105°F |
| 146 | 110°F |
| 158 | 115°F |
| 171 | 120°F |
- Checked against CoolProp, within 0.1 psig [same model]
No field-measured R-134a table exists, so this is equation-of-state reference data rather than a lab measurement, and every table available to us resolves to the same model.
A separate publisher can catch a transcription, edition or rounding error. A cross-check marked same model resolves to the same equation of state as the base table, so it is a consistency check rather than independent confirmation. One marked same printing prints numbers identical to another table listed here, so the two are one witness and we do not count them twice. Sources last re-verified 2026-08-25.
Read the low-side (suction) pressure and find its saturation temperature for superheat, and read the high-side (liquid) pressure and its saturation temperature for subcooling. The chart is in psig (gauge) and °F. To convert: kPa gauge = psig × 6.895; °C = (°F − 32) / 1.8.
R-134a PT Chart FAQs
What is the R-134a pressure at 40F and 100F?
On the R-134a PT chart, 40F saturation is about 35 psig and 100F is about 124 psig; 80F is about 87 psig. R-134a is a single-component refrigerant with zero glide, so the same saturation temperature serves both superheat (suction) and subcooling (liquid); there is no bubble and dew split.
Why does the R-134a chart go into a vacuum at low temperatures?
R-134a boils at about -15F at atmospheric pressure, so below roughly -15F its saturation pressure is a vacuum (inches of mercury) rather than a positive gauge pressure. This chart starts at the crossover near 0 psig and runs up in psig; medium-temp refrigeration and automotive AC operate above that point, so the positive-pressure table is what you use in the field.
Where is R-134a used?
R-134a is a medium-temperature refrigerant used in household and commercial refrigeration, water chillers, and older automotive air conditioning (newer vehicles use R-1234yf). It is being phased down under the AIM Act, so many new applications are moving to lower-GWP alternatives, but the large installed base keeps R-134a in active service.
What units is this R-134a PT chart in, and how do I convert to kPa or Celsius?
The table is in psig (gauge pressure) and degrees Fahrenheit, the field-standard units in North America. To convert pressure to kPa (gauge), multiply psig by 6.895. To convert temperature to Celsius, use C = (F - 32) / 1.8.
Related R-134a Tools
R-134a Superheat & Subcooling Calculator
Enter your readings; the calculator interpolates this PT chart and returns the verdict.
R-404A PT Chart
The low-temp commercial refrigeration blend, read on a single saturation column.
EPA Leak Rate Calculator
Run the AIM Act leak-rate math and thresholds for a 15+ lb refrigeration system.
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