R-134a pressure-temperature chart
R-134a pressure-temperature chart with bubble-point saturation pressure from -40°F to 140°F, generated from CoolProp.
What this refrigerant PT chart answers
R-134a is a single-component refrigerant used in older comfort-cooling and refrigeration applications.
This page is maintained by the HVAC Calculator Pro Editorial Team. We publish the inputs, calculation basis and limitations so a technician can reproduce the screening result and decide what must be checked in the field. It is a reference aid, not a substitute for the governing code, a licensed designer or the equipment manufacturer's instructions.
Bubble-point saturation table
gauge pressure · sea-level reference| Temperature | Equivalent | Pressure |
|---|---|---|
| -40 °F | -40.0 °C | -7.3 PSIG |
| -35 °F | -37.2 °C | -6.1 PSIG |
| -30 °F | -34.4 °C | -4.8 PSIG |
| -25 °F | -31.7 °C | -3.4 PSIG |
| -20 °F | -28.9 °C | -1.8 PSIG |
| -15 °F | -26.1 °C | -0.0 PSIG |
| -10 °F | -23.3 °C | 1.9 PSIG |
| -5 °F | -20.6 °C | 4.1 PSIG |
| 0 °F | -17.8 °C | 6.5 PSIG |
| 5 °F | -15.0 °C | 9.1 PSIG |
| 10 °F | -12.2 °C | 11.9 PSIG |
| 15 °F | -9.4 °C | 15.0 PSIG |
| 20 °F | -6.7 °C | 18.4 PSIG |
| 25 °F | -3.9 °C | 22.1 PSIG |
| 30 °F | -1.1 °C | 26.1 PSIG |
| 35 °F | 1.7 °C | 30.4 PSIG |
| 40 °F | 4.4 °C | 35.0 PSIG |
| 45 °F | 7.2 °C | 40.1 PSIG |
| 50 °F | 10.0 °C | 45.4 PSIG |
| 55 °F | 12.8 °C | 51.2 PSIG |
| 60 °F | 15.6 °C | 57.4 PSIG |
| 65 °F | 18.3 °C | 64.0 PSIG |
| 70 °F | 21.1 °C | 71.1 PSIG |
| 75 °F | 23.9 °C | 78.7 PSIG |
| 80 °F | 26.7 °C | 86.7 PSIG |
| 85 °F | 29.4 °C | 95.2 PSIG |
| 90 °F | 32.2 °C | 104.3 PSIG |
| 95 °F | 35.0 °C | 113.9 PSIG |
| 100 °F | 37.8 °C | 124.2 PSIG |
| 105 °F | 40.6 °C | 135.0 PSIG |
| 110 °F | 43.3 °C | 146.4 PSIG |
| 115 °F | 46.1 °C | 158.4 PSIG |
| 120 °F | 48.9 °C | 171.2 PSIG |
| 125 °F | 51.7 °C | 184.6 PSIG |
| 130 °F | 54.4 °C | 198.7 PSIG |
| 135 °F | 57.2 °C | 213.6 PSIG |
| 140 °F | 60.0 °C | 229.2 PSIG |
How to use this R-134a pressure-temperature chart
- Identify the refrigerant and confirm the unit's design data plate.
- Measure line temperature at the same stable operating point as the gauge pressure.
- Use the chart to translate saturation temperature and then apply the manufacturer's superheat or subcooling procedure.
Worked example: A pressure-temperature lookup helps diagnose a stable state; it does not replace airflow, metering-device or leak checks. Match the measured pipe temperature to saturation pressure, then verify superheat or subcooling against the equipment documentation.
Record the result with the project address, equipment model, code edition and assumptions. That audit trail is more useful than copying a single number without its conditions.
Continue with the right tool
What is specific to R-134a
The single-component curve is suitable for a direct saturation lookup, subject to gauge accuracy and altitude reference.
Safety and climate profile: Safety classification A1; approximate 100-year GWP 1,430; single-component fluid with no blend glide.
PSIG is gauge pressure. Absolute pressure adds local atmospheric pressure, so a gauge reading cannot be compared directly with an absolute-pressure chart without conversion.
For the governing safety and refrigerant-transition context, consult the U.S. EPA refrigerant guidance and the equipment manufacturer documentation.
Use boundary: This table does not model line pressure drop, superheat, subcooling, altitude correction or field safety controls. Confirm the correct blend basis and dew/bubble convention before using it.
Common questions
Can I use the R-134a pressure alone to charge a system?
No. Pressure must be interpreted with line temperature, airflow, operating mode and the manufacturer's charging method.
Why does this R-134a page say bubble point?
Bubble point is the saturated-liquid reference used by this generated table. Zeotropic blends may also require a dew-point reference, so the service procedure controls.