A refrigerant temperature-pressure chart serves as a simple tool for obtaining the necessary values. It is also called a PT chart or PT card. The PT chart comes with a pressure value and its relevant boiling point. A refrigerant with these conditions is called saturated. Saturated refrigerants are 100 percent vapor or liquid mixture with vapor or sometimes 100 percent liquid.
In this tutorial, we will learn about the R-404A temperature-pressure chart and practical applications. So let’s get started.
What is Refrigerant R-404A
Refrigerant R404a is an azeotropic mixture of three hydrofluorocarbons that was first made in the 1990s to use as a replacement for refrigerants that affect the ozone layer, like R502 and R22 refrigerants.
It has been used since it offers good thermodynamic features at low and medium evaporation temperatures.
R404A is commonly used in commercial cooling systems and has been used as a standard for more than 2 years.
This material comes with HFC-125, HFC-143a, and HFC-134a in a ratio of 44:52:4, respectively. That is non-flammable and comes with low toxicity, about 3920 global warming potential, but less compared to R-404a.
R404A refrigerant gas comes with zero ozone depletion and, after phasing out in 2020, is claimed to be used until 2030
R404 Refrigerant Features
| Technical Feature | Details |
| Refrigerant Type | HFC (Hydrofluorocarbon) Zeotropic Blend |
| ASHRAE Designation | R404A |
| Composition | R125 (44%) / R143a (52%) / R134a (4%) |
| Chemical Formula | Blend of CHF₂CF₃, CH₃CF₃, and CH₂FCF₃ |
| Molecular Weight | 97.6 g/mol |
| Safety Classification | A1 (Non-flammable, Low Toxicity) |
| Ozone Depletion Potential (ODP) | 0 |
| Global Warming Potential (GWP, AR4) | 3,922 |
| Boiling Point (1 atm) | −46.5°C (−51.7°F) |
| Critical Temperature | 72.1°C (161.8°F) |
| Critical Pressure | 3.73 MPa (541 psi) |
| Critical Density | 484 kg/m³ |
| Temperature Glide | 0.5–0.7°C |
| Liquid Density (25°C) | 1,045 kg/m³ |
| Vapor Density (25°C) | 66 kg/m³ |
| Lubricant Compatibility | POE (Polyol Ester) Oil |
| Charging Method | Liquid Phase Only |
| Operating Pressure | Similar to R502; Medium- to High-Pressure Refrigerant |
| Evaporating Range | −45°C to −10°C |
| Condensing Range | 25°C to 55°C |
| Color Code (Cylinder) | Orange (legacy identification in many regions) |
R-404A Temperature Pressure Chart (Saturation Pressure-Temperature Table)
| Temperature (°F) | Temperature (°C) | Pressure (PSIG) | Pressure (Bar) |
| -50°F | -45.6°C | 5.4 psi | 0.37 bar |
| -40°F | -40.0°C | 10.5 psi | 0.72 bar |
| -30°F | -34.4°C | 17.4 psi | 1.20 bar |
| -20°F | -28.9°C | 26.3 psi | 1.81 bar |
| -10°F | -23.3°C | 37.2 psi | 2.57 bar |
| 0°F | -17.8°C | 50.0 psi | 3.45 bar |
| 10°F | -12.2°C | 64.9 psi | 4.47 bar |
| 20°F | -6.7°C | 82.0 psi | 5.65 bar |
| 30°F | -1.1°C | 101.5 psi | 7.00 bar |
| 40°F | 4.4°C | 123.0 psi | 8.48 bar |
| 50°F | 10.0°C | 147.0 psi | 10.14 bar |
| 60°F | 15.6°C | 173.0 psi | 11.93 bar |
| 70°F | 21.1°C | 203.0 psi | 14.00 bar |
| 80°F | 26.7°C | 237.0 psi | 16.34 bar |
| 90°F | 32.2°C | 275.0 psi | 18.96 bar |
| 100°F | 37.8°C | 318.0 psi | 21.92 bar |
| 110°F | 43.3°C | 365.0 psi | 25.17 bar |
| 120°F | 48.9°C | 418.0 psi | 28.82 bar |
| 130°F | 54.4°C | 475.0 psi | 32.75 bar |
| 140°F | 60.0°C | 540.0 psi | 37.23 bar |
R404A Typical Operating Pressure Range
| Application | Evaporating Temperature | Suction Pressure Range | Discharge Pressure Range |
| Low Temperature Freezer | -40°F to -10°F (-40°C to -23°C) | 10–40 PSI | 200–300 PSI |
| Medium Temperature Refrigeration | 20°F to 40°F (-7°C to 4°C) | 80–125 PSI | 250–350 PSI |
| Walk-in Cooler | 25°F to 35°F (-4°C to 2°C) | 90–120 PSI | 250–325 PSI |
| Ice Machine | 10°F to 25°F (-12°C to -4°C) | 65–100 PSI | 250–325 PSI |
R404A Pressure Conversion Chart
| PSI | Bar | kPa |
| 50 PSI | 3.45 bar | 345 kPa |
| 100 PSI | 6.89 bar | 689 kPa |
| 150 PSI | 10.34 bar | 1034 kPa |
| 200 PSI | 13.79 bar | 1379 kPa |
| 250 PSI | 17.24 bar | 1724 kPa |
| 300 PSI | 20.68 bar | 2068 kPa |
| 350 PSI | 24.13 bar | 2413 kPa |
| 400 PSI | 27.58 bar | 2758 kPa |
| 500 PSI | 34.47 bar | 3447 kPa |
R404A Saturation Pressure Chart
| Saturation Temperature | Pressure (PSIG) | Pressure (Bar) |
| -40°C | 10.5 PSI | 0.72 bar |
| -35°C | 17 PSI | 1.17 bar |
| -30°C | 22 PSI | 1.52 bar |
| -25°C | 31 PSI | 2.14 bar |
| -20°C | 42 PSI | 2.90 bar |
| -15°C | 53 PSI | 3.65 bar |
| -10°C | 67 PSI | 4.62 bar |
| -5°C | 82 PSI | 5.65 bar |
| 0°C | 101 PSI | 6.96 bar |
| 5°C | 123 PSI | 8.48 bar |
| 10°C | 147 PSI | 10.14 bar |
| 15°C | 173 PSI | 11.93 bar |
| 20°C | 203 PSI | 13.99 bar |
| 25°C | 237 PSI | 16.34 bar |
| 30°C | 275 PSI | 18.96 bar |
| 35°C | 318 PSI | 21.92 bar |
| 40°C | 365 PSI | 25.17 bar |
| 45°C | 418 PSI | 28.82 bar |
| 50°C | 475 PSI | 32.75 bar |
R404A Saturation Temperature Chart
| Pressure (PSIG) | Saturation Temperature (°F) | Saturation Temperature (°C) |
| 10 PSI | -40°F | -40°C |
| 20 PSI | -27°F | -33°C |
| 30 PSI | -21°F | -29°C |
| 40 PSI | -8°F | -22°C |
| 50 PSI | 0°F | -18°C |
| 75 PSI | 15°F | -9°C |
| 100 PSI | 30°F | -1°C |
| 125 PSI | 41°F | 5°C |
| 150 PSI | 51°F | 11°C |
| 175 PSI | 61°F | 16°C |
| 200 PSI | 69°F | 21°C |
| 250 PSI | 84°F | 29°C |
| 300 PSI | 96°F | 36°C |
| 350 PSI | 107°F | 42°C |
| 400 PSI | 117°F | 47°C |
R404A Pressure vs Temperature Chart
| Temperature | Pressure | Application Range |
| -40°C | 10 PSI | Deep Freezing |
| -30°C | 22 PSI | Low Temperature Freezer |
| -20°C | 42 PSI | Frozen Food Storage |
| -10°C | 67 PSI | Low Temp Refrigeration |
| 0°C | 101 PSI | Medium Refrigeration |
| 10°C | 147 PSI | Cooler Applications |
| 20°C | 203 PSI | Condensing Reference |
| 30°C | 275 PSI | Condenser Operation |
| 40°C | 365 PSI | High Ambient Conditions |
| 50°C | 475 PSI | High Pressure Region |
R404A Charging Pressure Chart
| System Type | Evaporator Temperature | Charging Pressure Range |
| Deep Freezer | -35°C to -25°C | 15–35 PSI |
| Low Temperature Freezer | -25°C to -10°C | 35–65 PSI |
| Walk-in Freezer | -15°C to -5°C | 50–80 PSI |
| Display Case | -10°C to 0°C | 65–100 PSI |
| Cooler System | 0°C to 10°C | 100–150 PSI |
R404A Troubleshooting Pressure Chart
| PSI | Bar | kPa |
| 25 PSI | 1.72 bar | 172 kPa |
| 50 PSI | 3.45 bar | 345 kPa |
| 75 PSI | 5.17 bar | 517 kPa |
| 100 PSI | 6.89 bar | 689 kPa |
| 150 PSI | 10.34 bar | 1034 kPa |
| 200 PSI | 13.79 bar | 1379 kPa |
| 300 PSI | 20.68 bar | 2068 kPa |
| 400 PSI | 27.58 bar | 2758 kPa |
| 500 PSI | 34.47 bar | 3447 kPa |
R404A Refrigerant Pressure Comparison Chart (R404A vs R134a vs R507 vs R448A vs R449A)
A basic replacement of R404A is R407A refrigerant. 404 refrigerant composition that can replace R-502 and R-22 in industrial refrigeration applications.
| Parameter | R404A | R134a | R507 | R448A | R449A |
| Refrigerant | HFC Blend | HFC Pure Refrigerant | HFC Azeotropic Blend | HFO/HFC Blend | HFO/HFC Blend |
| Composition | R125/R143a/R134a | CH₂FCF₃ | R125/R143a | R32/R125/R134a/R1234ze/R1234yf | R32/R125/R134a/R1234yf/R1234ze |
| Blend Ratio | 44/52/4% | 100% R134a | 50/50% | Multi-component Blend | Multi-component Blend |
| ASHRAE Safety Class | A1 | A1 | A1 | A1 | A1 |
| Ozone Depletion Potential (ODP) | 0 | 0 | 0 | 0 | 0 |
| Global Warming Potential (GWP) | ~3922 | ~1430 | ~3985 | ~1273 | ~1397 |
| Molecular Weight | 97.6 g/mol | 102 g/mol | 98.9 g/mol | 86.4 g/mol | 87.2 g/mol |
| Boiling Point | -46.5°C | -26.3°C | -46.7°C | -45.8°C | -46.0°C |
| Critical Temperature | 72.1°C | 101.1°C | 70.9°C | 83°C | 82°C |
| Temperature | 0.5–0.7°C | None | Near Zero | ~6.4°C | ~4.5°C |
| Lubricant | POE Oil | POE Oil | POE Oil | POE Oil | POE Oil |
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