HVAC Glossary

R-404A

Last updated: March 11, 2026

R-404A is a hydrofluorocarbon (HFC) blend refrigerant composed of three components that provides medium-temperature cooling for commercial refrigeration and some air conditioning systems. This zeotropic blend (44 percent R-125, 52 percent R-143a, 4 percent R-134a) offers excellent thermodynamic performance across refrigeration temperatures of 35°F to 55°F, making it popular for walk-in coolers, freezers, and transport refrigeration. R-404A has a high global warming potential of 3,922 and faces phase-down under the Kigali Amendment.

System Requirements

R-404A operates at 25 to 30 percent higher pressures than R-502, requiring robust compressors and strong aluminum or steel tubing. POE synthetic oils are mandatory for compatibility, and the refrigerant exhibits significant glide of approximately 0.5°F across the evaporating and condensing range. System capacity per pound exceeds R-12 alternatives by 10 to 15 percent.

Environmental Compliance

R-404A phase-down mandates 40 percent reduction by 2024 and 80 percent by 2030 in developed nations. Low-GWP replacements including R-407A, R-407F, and R-449A are approved alternatives requiring system modifications. Existing R-404A equipment continues operation with reclaimed refrigerant through the transition period.

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