R448A Refrigerant26/26/21/20/7 blend · Commercial refrigeration · R404A/R507A transition
R448A is a five-component zeotropic HFC/HFO blend developed for medium- and low-temperature commercial refrigeration. It became a major A1 retrofit and new-equipment option for systems historically using R404A, R507A and, in selected procedures, R22. Its lower GWP reduces direct climate impact versus R404A, but its meaningful temperature glide and higher discharge temperature in some operating conditions require correct PT data, liquid charging and component checks.
What is R448A refrigerant?
R448A combines R32, R125, R134a, R1234yf and R1234ze(E) in nominal mass fractions of 26/26/21/20/7. It is classified A1 and has an EPA Technology Transitions GWP of 1,386. The blend is especially associated with supermarket racks, walk-ins, cold rooms and other DX commercial refrigeration. It should be treated as an engineered retrofit option rather than a universal drop-in replacement.
R448A refrigerant properties
Use these values for research and screening. For equipment design, charging and compliance, use the exact supplier PT data, SDS, OEM documentation and regulation that governs the project.
| Property | Reference | Engineering / source note |
|---|---|---|
| Designation | R448A | ASHRAE refrigerant designation |
| Nominal composition | R32/R125/R134a/R1234yf/R1234ze(E) = 26/26/21/20/7 mass % | EPA HFC blend documentation / REFPROP mixture definition |
| Refrigerant type | Zeotropic HFC/HFO blend | Five components |
| ODP | 0 | No ozone depletion |
| 100-year GWP | 1,386 | EPA Technology Transitions calculated value |
| Safety classification | A1 | Lower toxicity / no flame propagation |
| Temperature glide | Meaningful; Honeywell PT data show bubble/dew separation around 10–11°F at low pressures | Use exact PT chart for the operating pressure |
| Charging practice | Liquid transfer commonly required | Helps preserve blend composition |
| Typical lubricant | POE in common R404A/R507A retrofit platforms | Always confirm compressor/OEM approval |
| Primary legacy comparison | R404A / R507A | Commercial refrigeration retrofit / transition |
EPA Technology Transitions uses the values shown on this page. Older product literature may use IPCC AR4/AR5 or another assessment, so a different number is not automatically an error.
Where is R448A used?
Applications must be evaluated by system type, charge, compressor, heat exchanger, safety class and current regulation. The examples below describe recognized use contexts, not automatic approval for every installation.
Supermarket refrigeration
Parallel racks, display cases and distributed DX systems where equipment is approved for R448A.
Walk-in coolers & freezers
Medium- and low-temperature commercial systems transitioning away from R404A/R507A.
Remote condensing units
Common retrofit/new-equipment context where current U.S. GWP limits and charge size must be checked.
Cold rooms & food service
Restaurants, food distribution and storage systems with qualified compressors and valves.
Selected industrial process refrigeration
EPA SNAP has accepted R448A in relevant new/retrofit end uses, but Technology Transitions limits can now be more restrictive.
Ice rinks / specialty systems
Used in selected positive-displacement systems where the equipment and regulatory pathway allow it.
Continue through the Refrigerant Replacements and Low-GWP Refrigerants hubs for broader selection context.
R448A composition and why five components matter
R448A contains three HFCs—R32, R125 and R134a—and two HFOs—R1234yf and R1234ze(E). EPA’s HFC allocation documentation uses the nominal 26/26/21/20/7 mass composition when calculating the blend’s HFC exchange value.
The HFO fraction is one reason R448A has substantially lower GWP than R404A, but R448A is still far above the <150 GWP class now used in several long-term refrigeration regulations.
Because it is zeotropic, field service must account for bubble point, dew point and composition behavior rather than treating R448A as a pure fluid.
R448A temperature glide, bubble point and dew point
Honeywell’s current R448A PT chart publishes separate bubble, average and dew temperatures. At low pressures the bubble-to-dew separation is roughly 10–11°F, demonstrating why a single saturation temperature is not sufficient.
For field calculations, use the manufacturer’s guidance for superheat and subcooling and the correct saturation endpoint. Controller setup may offer separate R448A bubble, dew and midpoint selections.
Temperature glide can also affect heat-exchanger temperature profiles. A retrofit should therefore evaluate evaporator/condenser approach temperatures and control settings rather than only matching suction pressure.
R404A / R507A retrofit: what should be checked
R448A is widely used as an R404A/R507A transition option, but compressor qualification, operating envelope, discharge temperature, expansion valve capacity, controller settings, safety switches, line sizing and refrigerant charge should all be reviewed.
Danfoss guidance published in 2026 explicitly separates three paths: drop-in only where the condensing unit is already qualified, retrofit/redesign where qualification or sizing requires changes, and new installation designed around the target refrigerant.
Filter-drier and sight-glass replacement, leak repair and final commissioning are common elements of a professional retrofit. The objective is not merely to change cylinder color; the system must operate inside the approved envelope.
Why liquid charging and leak history matter
R448A is a zeotropic blend. Charging liquid from the cylinder helps preserve the specified composition; repeatedly transferring vapor can alter what enters the system.
After a significant leak, the remaining circulating composition may be affected by the location, phase and duration of the release. Follow the refrigerant supplier and equipment manufacturer guidance before deciding whether a top-off is acceptable.
A refrigerant identifier or laboratory analysis can be valuable when the recovery cylinder may contain mixed or fractionated refrigerant.
R448A vs R404A
The table highlights engineering differences rather than implying direct interchangeability.
| Characteristic | R448A | R404A |
|---|---|---|
| Refrigerant type | 5-component zeotropic HFC/HFO blend | Near-azeotropic HFC blend |
| EPA GWP | 1,386 | 3,922 |
| Safety class | A1 | A1 |
| Temperature glide | Meaningful | Very small |
| Typical role | Lower-GWP retrofit / transition | Legacy high-GWP refrigeration |
| Discharge temperature | Can be higher in some retrofits | Usually lower baseline in the same legacy platform |
| Current U.S. long-term fit | Subsector-dependent; above future 150/300 limits | Poorer due much higher GWP |
R448A safety: A1 simplifies flammability, but blend and service hazards remain
R448A is classified A1. Flammability is therefore not the primary design constraint, but large releases can displace oxygen, liquid refrigerant can cause frostbite, and hot work can create hazardous decomposition products. Correct recovery and charging also matter because R448A is zeotropic.
Oxygen displacement
Large leaks in confined rooms can reduce breathable oxygen.
Cold injury
Liquid and flashing refrigerant can cause severe cold burns.
Blend management
Use R448A-specific charging, PT data and leak detection rather than component-only assumptions.
Actual risk depends on charge, release rate, pressure, room volume, ventilation, ignition sources, equipment construction, alarm logic and service condition.
See the Refrigerant Safety Guide for classification context.
R448A refrigerant leak detection
Validate detector response to the finished blend
Use fixed or portable detection validated for the finished R448A blend. Infrared and semiconductor technologies are common depending on the range and application. A detector calibrated only for R32, R125 or R134a should not automatically be assumed to provide the required response to the complete blend. GasNose lists R448A among its validated refrigerant detection profiles.
Portable service leak detectors, fixed area monitors, A2L mitigation sensors and refrigerant identifiers perform different functions. Define the alarm action and concentration range before selecting the technology.
Regulatory position of R448A in 2026
United States
EPA SNAP continues to list R448A as acceptable in multiple refrigeration end uses, but Technology Transitions rules can be more restrictive. As of July 27, 2026, new cold-storage warehouse systems face an interim GWP 700 limit, so R448A (1,386) does not fit that new-system pathway. Remote condensing units use an interim 1,400 limit from July 27, 2026, and supermarket systems use 1,400 from January 1, 2027; R448A is just below that interim threshold. Those categories tighten to 150 or 300 in 2032 depending on configuration/charge.
European Union
R448A has a much lower GWP than R404A but remains a fluorinated greenhouse-gas blend with GWP well above 150. EU Regulation 2024/573 progressively reduces the long-term new-equipment space for refrigerants in this GWP range, while existing systems still create service and transition demand.
Is R448A being phased out?
R448A is best viewed as a transition refrigerant rather than a final universal solution. It can extend the life of qualified R404A/R507A equipment and fit selected interim U.S. limits, but future 150/300 GWP thresholds favor lower-GWP A2L, hydrocarbon or CO₂ architectures.
U.S. refrigeration limits differ by cold storage, supermarket, remote condensing, stand-alone product, industrial process and chiller category. A refrigerant may fit one pathway and fail another.
Use the Refrigerant Regulations Hub for regional research.
What should be compared with R448A?
Compare the real equipment pathway: retrofit vs new system, A1 vs A2L capability, GWP threshold, glide, compressor envelope, energy efficiency and service ecosystem.
Practical misconceptions about R448A
“R448A is a drop-in for every R404A system.”
Only systems with compatible/approved compressors, valves, controls and operating envelope should be converted.
“R448A has one saturation temperature.”
It is zeotropic; bubble and dew values differ materially.
“A1 means refrigerant leaks are harmless.”
Large releases can cause oxygen displacement, cold injury and decomposition hazards.
“GWP 1,386 means it fits every current U.S. refrigeration limit.”
It is below the 1,400 interim limit in some retail-food subsectors but above current 700 and future 150/300 limits in others.
R448A refrigerant FAQ
Concise answers to common composition, retrofit, glide, safety and regulation questions.
What is R448A refrigerant?
What is the EPA GWP of R448A?
What is R448A made of?
Is R448A flammable?
Does R448A have temperature glide?
Can R448A replace R404A?
Should R448A be charged as liquid?
Is R448A allowed in new U.S. cold storage warehouses in 2026?
Can R448A fit the U.S. remote-condensing-unit interim limit?
How is an R448A leak detected?
R448A sources and further reading
This profile uses current EPA regulatory references plus refrigerant supplier, NIST, scientific and GasNose resources. Re-check the latest edition before design or compliance decisions.
Working with R448A or planning a refrigerant transition?
Compare GWP, safety class, temperature glide, equipment compatibility and regulatory lifetime before selecting a refrigerant.
Technical Notice: This page is for refrigerant research and general technical reference. Refrigerant suitability, permitted charge, equipment approval, leak mitigation, servicing procedures and regulatory compliance depend on the exact equipment, installation and jurisdiction. Always verify current manufacturer documentation, SDS, applicable standards and local regulations before selecting, replacing, charging or servicing a refrigerant.