R-290 (Propane, natural, A3)
R-290 (Propane) PT Chart
The full R-290 pressure-temperature reference table, from -20 to 130°F. R-290 is pure propane, a single-component refrigerant, so the chart is one saturation column with zero glide. Reference data from NIST REFPROP (National Refrigerants bulletin), cross-checked against the Hudson Technologies R-290 chart.
R-290 Pressure-Temperature Table
| Pressure (psig) | Sat. Temp (°F) |
|---|---|
| 10.7 | -20°F |
| 16.7 | -10°F |
| 23.7 | 0°F |
| 31.8 | 10°F |
| 41.1 | 20°F |
| 46.3 | 25°F |
| 51.8 | 30°F |
| 57.7 | 35°F |
| 63.9 | 40°F |
| 70.6 | 45°F |
| 77.6 | 50°F |
| 85.1 | 55°F |
| 93 | 60°F |
| 101.4 | 65°F |
| 110.2 | 70°F |
| 119.5 | 75°F |
| 129.3 | 80°F |
| 139.7 | 85°F |
| 150.5 | 90°F |
| 161.9 | 95°F |
| 173.9 | 100°F |
| 186.5 | 105°F |
| 199.6 | 110°F |
| 227.8 | 120°F |
| 258.7 | 130°F |
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-290 PT Chart FAQs
What is the R-290 pressure at 40F and 100F?
On the R-290 (propane) PT chart, 40F saturation is about 64 psig and 100F is about 174 psig; 60F is about 93 psig and 90F is about 151 psig. R-290 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.
Is R-290 the same pressure as R-22?
Their pressures sit close, so the numbers look similar on a gauge. That similarity does not make R-290 a substitute: R-290 is an A3 highly flammable refrigerant, so it is only used in equipment specifically designed and listed for it, with strict charge limits, and is never charged into a system built for R-22.
How much R-290 can a system hold?
R-290 is classified A3 (highly flammable) by ASHRAE 34, so the charge is capped by the equipment safety standard rather than by system tonnage. The ceiling depends on the appliance type, the room, and the UL or IEC standard the unit is listed to, and it is set by that listing, not by a field rule of thumb. Always follow the equipment nameplate and the standard the unit is built and listed to.
What units is this R-290 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 HVAC Tools
Superheat & Subcooling Calculator
Enter your readings; the calculator interpolates the PT chart and returns the verdict.
R-404A PT Chart
The HFC low-temp commercial refrigeration blend, read on a single saturation column.
A2L Charge Limit Calculator
Maximum flammable-refrigerant charge for a room, or minimum room area for a charge.
Keep going