What R-449A is and where it is used
R-449A is a four-part blend of R-32, R-125, R-1234yf and R-134a. Chemours sells it as Opteon XP40. It is nonflammable, with an ASHRAE A1 rating. Chemours developed it to replace R-404A and R-507 in low- and medium-temperature direct-expansion refrigeration: supermarket racks and distributed systems, walk-in coolers and freezers, condensing units and cold storage. It goes into new equipment and is also used to retrofit existing R-404A, R-507 and R-22 systems.
Chemours lists an AR5 GWP of 1,282, a 67% cut from R-404A and R-507. Do not read the R-448A chart for an R-449A system. They are different blends, and each has its own pressure-temperature data.
How to read the R-449A chart
R-449A is a zeotropic blend with a temperature glide, so each temperature has two pressures. The bubble (liquid) column is the pressure at which liquid starts to boil. The dew (vapor) column is the pressure at which the last drop evaporates. At 40°F the chart gives 87.4 psig bubble and 71.6 psig dew. Read the other way, the glide at a fixed pressure is about 9.9°F at 40 psig and 8.1°F at 240 psig. See bubble point, dew point and glide.
- Superheat: convert suction pressure with the dew column. At 40 psig suction the dew point is 16.2°F. Use the superheat calculator.
- Subcooling: convert liquid line pressure with the bubble column. At 240 psig the bubble point is 100.0°F. Use the subcooling calculator.
Chemours' retrofit guide gives the same rule: dew for superheat, bubble for subcooling. Using one column for both will throw either number off by roughly the glide.
Typical R-449A pressures in commercial refrigeration
Chemours compares refrigerants at a 104°F condensing temperature, a 14°F medium-temperature evaporator and a -22°F low-temperature evaporator. At those saturation temperatures the chart gives:
- Medium-temperature suction (dew at 14°F): 37.6 psig
- Low-temperature suction (dew at -22°F): 8.6 psig
- Condensing at 104°F: 254.0 psig bubble, 225.7 psig dew
For comparison, R-404A at a 14°F dew point is 47.8 psig, so expect lower suction pressure after a conversion. These are saturation values, not targets. Chemours notes that actual performance depends on equipment conditions and operating environment, and the equipment manual governs.
Service notes
- Charge as liquid. Remove only liquid from the cylinder (dip tube, or cylinder inverted). If it goes into the suction side, flash it through the manifold or a throttling valve. Chemours warns that liquid charged into the suction line can cause irreversible compressor damage.
- Oil. The POE already in an R-404A or R-507 system is usually suitable. Chemours recommends an oil change and seal replacement when converting from R-22.
- Retrofit charge. Chemours suggests starting at about 85% of the original R-404A or R-507 charge. The final charge usually ends near 105%.
- Controls. Chemours says EPRs and cutouts may need resetting, and rack controllers should be updated with R-449A properties. Discharge temperature runs modestly higher than R-404A.
- Leaks. Chemours states the blend can be topped off after leaks.
Regulatory status and what comes next
EPA's May 2026 amendments set an interim GWP limit of 1,400 for new supermarket systems and remote condensing units, running until Jan 1, 2032. EPA calculates R-449A at 1,396, so it fits that window. From 2032 the limit drops to 150 or 300, depending on charge size and configuration. R-744 (CO2), at an EPA GWP of 1, is under those limits, and EPA lists it as acceptable in retail food refrigeration. EPA's rule does not restrict the continued use of existing systems, which may be serviced and repaired throughout their useful life.