What Refrigerants Can R290 Replace?

A Global Shift Toward Lower-GWP Refrigerants

The climate impact of refrigerants has become a growing concern worldwide. Gas released through leaks or at equipment disposal can contribute substantially to global warming, even when the appliance itself uses electricity efficiently. The EU’s F-gas Regulation (EU) 2024/573, applicable since March 2024, tightens the HFC phase-down and introduces further restrictions on fluorinated refrigerants in specific equipment categories. These rules give manufacturers a stronger reason to develop products using low-GWP alternatives such as R290. The regulation does not prescribe R290 as the solution; it makes continued reliance on high-GWP refrigerants increasingly difficult in the applications it covers.

Which Refrigerants Can R290 Replace?

R290 can replace R22, R134a and R404A in certain refrigeration and air-conditioning applications. Its role differs with each refrigerant. For R22, the technical interest comes partly from their similar pressure characteristics. For R134a and R404A, R290 offers manufacturers a low-GWP option for new commercial refrigeration equipment. Here, replacement often means introducing an appliance designed for R290 to perform the same cooling task. It does not mean that an existing appliance can accept R290 without modification.

R290 as an Alternative to R22

R22 and R290 have relatively close saturation pressures at common refrigeration temperatures, which helps explain the long-standing interest in propane as an alternative. R290 also avoids the ozone depletion associated with R22. Air-conditioner studies have demonstrated useful cooling performance with R290, including experiments that adjusted the original refrigerant circuit. Similar pressure behavior provides a starting point for development, but it does not establish equal cooling capacity or lower electricity consumption in every system. R290’s flammability also introduces safety requirements that an original R22 appliance may not meet.

R290 as an Alternative to R134a

R290 has taken over some applications previously served by R134a, particularly in self-contained commercial refrigerators and display cabinets. It has a higher volumetric refrigeration capacity, allowing a smaller compressor displacement for the same cooling duty under comparable conditions. Its saturation pressure is also higher at the same temperature. These differences explain why an R290 version of a cabinet requires a compressor and refrigerant circuit matched to R290. A cabinet that looks similar from the outside may have a substantially different refrigeration assembly inside.

R290 as an Alternative to R404A

R290 is also an established alternative to R404A in small commercial refrigeration equipment, including freezers. Its very low GWP reduces the direct climate impact of refrigerant leakage compared with R404A. Factory-built cabinets offer a practical setting for this transition because the manufacturer can develop and validate the complete refrigerant circuit as one unit. This experience does not automatically extend to a large centralized R404A installation. A system distributing refrigerant across multiple cabinets presents a different engineering problem from a compact, self-contained freezer.

References

1. European Commission — EU legislation on fluorinated greenhouse gases
2. European Union — Regulation (EU) 2024/573
3. Danfoss — Hydrocarbons: Properties, applications and safety
4. Danfoss — R404A/R507A replacement: Your main questions answered
5. Secop — Practical Application of Refrigerants R600a and R290 in Small Hermetic Systems (2018), Table 1 and servicing guidance
6. Journal of Refrigeration — Experiment on R290 Substituting for R22 in a Room Air-conditioner (2010)
7. Experimental Heat Transfer — Investigations on charge reduction strategies to use R290 as an alternative to R22 in a split air conditioner
8. BITZER — Refrigerant Report: Complete comparison table (GWP AR6, ODP, safety classes and normal boiling/dew points)