Can I use R507A instead of R404A?

R507A and R404A are not directly interchangeable. Always use the refrigerant specified for the system. For new fills, consider R448A or R449A as lower-GWP alternatives to both.

Which has a higher GWP, R404A or R507A?

R507A has a slightly higher GWP (3985) than R404A (3922). Both are high-GWP refrigerants subject to F-Gas restrictions.

Is R507A better than R404A for blast freezers?

R507A offers marginally better performance at very low temperatures (below -40C) due to its azeotropic nature. For standard commercial freezer temperatures, the difference is minimal.

R507A vs R404A UK: Which Is Better for Low-Temperature Refrigeration?

Admin

11 hours ago

R507A and R404A: Two Refrigerants, Similar Applications

R507A and R404A are both HFC blends widely used in UK low-temperature commercial refrigeration. They are often specified for similar applications — frozen food display cabinets, blast freezers, cold stores and transport refrigeration — and are frequently compared when engineers specify or service low-temperature systems.

Key Differences

Composition

R404A: Blend of R125 (44%), R143a (52%) and R134a (4%)
R507A: Azeotropic blend of R125 (50%) and R143a (50%)

Because R507A is an azeotrope, it does not fractionate — it behaves as a single component. This makes it slightly easier to handle in terms of charging (vapour charging is acceptable) compared to R404A which requires care to prevent fractionation.

GWP

R404A GWP: 3922
R507A GWP: 3985

Both have very high GWPs and are subject to F-Gas phase-down restrictions. Neither is recommended for new installations in the UK.

Performance

R507A offers marginally better performance than R404A at very low evaporating temperatures (below -40°C), making it preferred for ultra-low temperature blast freezing applications. For standard commercial freezer work (-20°C to -30°C), performance differences are minimal.

The Bottom Line

For new installations, neither R404A nor R507A is recommended — switch to R448A or R449A. For servicing existing equipment, use the refrigerant the system was designed for. Our R404A 10.9 kg cylinders are available for legacy system maintenance. See our full refrigerant gas range.