High GWP - Phase-Down Zeotropic Blend

R-404A Refrigerant

HFC blend refrigerant widely used in commercial refrigeration. Subject to phase-down due to high GWP of 3922.

3922
Global Warming Potential
Type
Zeotropic Blend
Composition
R-125/143a/134a
Glide
0.7°F (0.4°C)
Boiling Point
-51.0°F (-46.1°C)
Critical Temp
161°F (72°C)
Oil Type
POE

R-404A Phase-Down in Progress

EPA AIM Act and EU F-Gas regulations are phasing down R-404A due to its high GWP of 3922. Plan for transition to lower-GWP alternatives.

Blend Composition

R-125
44%
R-143a
52%
R-134a
4%

Physical Properties

Molecular Weight 97.6 g/mol
Boiling Point -51.0°F (-46.1°C)
Critical Temperature 161°F (72°C)
Critical Pressure 541 psia
Liquid Density 76.8 lb/ft³
ODP 0
GWP (100-yr) 3922
Temperature Glide 0.7°F (0.4°C)
ASHRAE Safety A1 (Non-flammable)

Common Applications

  • Supermarket display cases
  • Walk-in coolers and freezers
  • Cold storage warehouses
  • Refrigerated transport
  • Ice machines
  • Commercial freezers

R-404A Pressure-Temperature Chart

Zeotropic Blend: R-404A has minimal temperature glide (~0.7°F). Bubble point is shown for liquid, dew point for vapor.

Temp °F Temp °C Bubble (psig) Dew (psig)
-60°F -51.1°C -6.2 -5.9
-50°F -45.6°C -2.2 -1.8
-40°F -40°C 2.4 2.9
-30°F -34.4°C 7.6 8.2
-20°F -28.9°C 13.6 14.3
-10°F -23.3°C 20.4 21.2
0°F -17.8°C 28.2 29.1
10°F -12.2°C 37 38
20°F -6.7°C 47 48.1
25°F -3.9°C 52.5 53.6
30°F -1.1°C 58.3 59.6
35°F 1.7°C 64.5 65.9
40°F 4.4°C 71.2 72.6
45°F 7.2°C 78.3 79.8
50°F 10°C 85.8 87.5
60°F 15.6°C 102.2 104.1
70°F 21.1°C 120.4 122.6
80°F 26.7°C 140.6 143.1
90°F 32.2°C 163 165.8
100°F 37.8°C 187.6 190.8
110°F 43.3°C 214.8 218.4
120°F 48.9°C 244.6 248.6
130°F 54.4°C 277.3 281.8

Lower-GWP Replacement Options

R-448A (Solstice N40)

GWP 1387

HFO/HFC blend, A1 safety classification

  • • 65% GWP reduction vs R-404A
  • • Compatible with existing POE oil
  • • Similar operating pressures
  • • 5-10% capacity reduction typical
  • • Non-flammable (A1)

R-449A (Opteon XP40)

GWP 1397

HFO/HFC blend, A1 safety classification

  • • 64% GWP reduction vs R-404A
  • • Compatible with existing POE oil
  • • Similar capacity to R-404A
  • • Good efficiency performance
  • • Non-flammable (A1)

R-407A

GWP 2107

HFC blend for medium-temp applications

  • • 46% GWP reduction vs R-404A
  • • Higher temperature glide (12°F)
  • • Lower capacity than R-404A
  • • Better for medium-temp only
  • • Non-flammable (A1)

R-407F (Performax LT)

GWP 1825

HFC blend optimized for low-temp

  • • 53% GWP reduction vs R-404A
  • • Good low-temp performance
  • • Higher temperature glide (9°F)
  • • Improved efficiency
  • • Non-flammable (A1)

Retrofit Considerations

  • • All replacements require TXV adjustment or replacement
  • • System must be thoroughly evacuated (no R-404A mixing)
  • • POE oil compatibility should be verified
  • • Higher glide refrigerants may require system modifications
  • • Consult manufacturer guidelines for specific equipment

R-404A Regulatory Timeline

Before 2020

R-404A widely available with no restrictions

2020 - EU Regulations

EU bans R-404A in new stationary commercial refrigeration equipment (hermetic systems <40 kW)

2022 - EU Extension

EU extends ban to all new commercial refrigeration equipment

2024+ - EPA AIM Act

US EPA restrictions on R-404A for new retail food refrigeration. Higher prices, limited availability.

2025 and Beyond

Continued phase-down. Plan for transition to lower-GWP alternatives for all applications.

R-404A Charging Guidelines

Charging Method

Liquid Charge Only

R-404A must be charged as a liquid to prevent fractionation of the blend components.

  • Charge liquid into the high side (liquid line) with system off
  • Or charge liquid into low side through flow restrictor with system running
  • Never vapor charge - causes blend fractionation

Target Operating Conditions

Medium Temperature (Walk-in Cooler)

Suction: 20-25 psig
Head: 225-275 psig
Superheat: 6-12°F
Subcooling: 8-12°F

Low Temperature (Freezer)

Suction: 0-8 psig
Head: 200-250 psig
Superheat: 8-15°F
Subcooling: 10-15°F