R-448A PT Chart and Refrigerant Profile

Where you will find R-448A

R-448A, sold as Solstice N40 and Forane 448A, is one of the two main A1 replacements for R-404A and R-507A in commercial refrigeration. Solstice lists it for supermarket racks, condensing units, stand-alone units, transport refrigeration and ice machines, both in new equipment and as a retrofit of R-404A, R-507A and R-22 systems (Solstice brochure).

Because so many R-448A systems are conversions, the compressor nameplate may still say R-404A or R-22. Look for a retrofit tag near the service valves or on the condensing unit, and check the label on the cylinder left on site. If the suction pressure looks far too low for the box temperature on an “R-404A” system, check whether you are reading a R-404A chart on a R-448A system: at a 40°F evaporating dew point, R-448A reads 71.2 psig and R-404A 85.4 psig on this site’s computed charts.

Charging R-448A

R-448A is a zeotropic blend with a large glide: about 10.8°F at 40°F evaporating and 9.1°F at 100°F condensing, from the computed data. Solstice states it is essential to charge the system with liquid from the cylinder, and to throttle that liquid into the suction side so it flashes before reaching the compressor. Vapor charging changes the blend composition left in the cylinder and in the system.

Column choice matters more than on R-404A. At 40°F the bubble (liquid) pressure is 89.3 psig and the dew (vapor) pressure is 71.2 psig, 18 psi apart. Use the dew column with suction pressure for superheat and the bubble column with liquid-line pressure for subcooling. Reading the wrong column turns a normal superheat into an apparent flood or a starved coil.

On TXV and EEV systems, charge to the equipment or retrofit guideline’s subcooling target and check it with the subcooling calculator. Self-contained units with capillary tubes are charged by weight to the nameplate. The target superheat calculator is based on the CEC air-conditioner table and is not meant for refrigeration cases. The glide calculator shows the glide at your actual pressure, and the PT chart guide explains bubble and dew in more detail.

This chart was spot-checked against Honeywell’s R-448A PT chart; the largest difference was 1.7 psi at 100°F dew, which the validation section below lists.

Oil and compatibility

Use POE. Solstice says miscible synthetic lubricants such as POE should be used, and that mineral oil and alkylbenzene are immiscible with R-448A. Copeland’s approved-lubricant bulletin (AE 93-11) lists POE for R-448A compressors.

In R-404A and R-507A retrofits the existing POE is suitable, according to Solstice. For R-22 systems running mineral oil, Solstice says about 5% residual mineral oil is acceptable, so a single oil change may be enough; confirm against the retrofit guideline before charging. See the oil types guide.

Safety, handling and recovery

R-448A is class A1 (lower toxicity, no flame propagation), even though it contains HFO components. No A2L tools are required, but it is a high-pressure appliance refrigerant under 40 CFR 82.152, so Section 608 Type II or Universal certification applies, and sales are restricted to certified technicians.

Required recovery levels for equipment made after November 15, 1993 (40 CFR 82.156): 0 in Hg for systems under 200 lb, 10 in Hg at 200 lb or more. Use a recovery machine certified to Appendix B3 (AHRI 740) and keep recovered R-448A in its own recovery cylinder.

Systems with 15 lb or more of HFC are covered by the leak repair rules in 40 CFR 84.106 from January 1, 2026; commercial refrigeration with 1,500 lb or more also needs automatic leak detection (84.108).

The legacy label color for R-448A is gentian blue. New containers since January 1, 2020 are light green-gray (RAL 7044) under AHRI Guideline N-2017, with the color only on the label. See cylinder colors.

Status and replacements

R-448A’s GWP (1,387 on the AR4 basis, 1,386.1 in EPA’s 40 CFR 84.64 calculation) sits just under the 1,400 limit that the May 2026 final rule (91 FR 31284) set for new remote condensing units from July 27, 2026 and new supermarket systems from January 1, 2027. That makes it usable in those new systems until the lower 150/300 limits apply on January 1, 2032. It is above the 700 limit for new cold storage from July 27, 2026, although EPA SNAP had listed it acceptable for cold storage warehouses in 2017.

R-448A is an HFC/HFO blend, so its HFC content is still subject to the AIM Act allowance phasedown (30% of baseline from 2029). From January 1, 2029, servicing supermarket systems, refrigerated transport and automatic commercial ice makers requires reclaimed refrigerant (40 CFR 84.112(e)).

For new low-GWP equipment the next step is A2L blends such as R-454A, R-454C and R-455A, or CO2 (R-744). The closest sibling is R-449A; see R-448A vs R-449A and the R-404A replacement comparison.

Common questions

What is the difference between R-448A and R-449A?

Both are A1 POE blends of R-32, R-125, R-1234yf and R-134a with similar pressures; R-448A adds 7% R-1234ze(E). R-448A has a GWP of 1,387 and R-449A 1,397 (AR4 basis). Do not mix them in one system; charge whichever the system is tagged for.

Can R-448A replace R-22?

Solstice lists R-22 retrofits, with the oil changed to POE until about 5% mineral oil remains. Follow the retrofit guideline and the compressor maker’s approval.