R448A vs R404A: Differences, Performance, and Replacement Guide

R404A has served commercial refrigeration systems for decades, but its high global warming potential has encouraged equipment owners and contractors to evaluate lower-GWP alternatives. R448A is one of the refrigerants frequently considered for this purpose.

The most important point is that R448A is not a universal or drop-in replacement for R404A. It can be used in certain approved low- and medium-temperature systems, but a successful conversion requires equipment verification, complete refrigerant recovery, charging adjustments, control changes, and post-retrofit performance testing.

This guide compares R448A and R404A and explains what contractors and equipment owners should check before making a replacement decision.

R448A vs R404A at a Glance

The GWP values above use the figures published in U.S. EPA and Copeland materials so that both refrigerants are compared using a consistent basis. Some newer refrigerant documents may display a different R448A GWP because the underlying scientific assessment methodology has changed. A valid comparison must use values calculated under the same methodology.

The EPA lists R448A with a GWP of 1,387, an A1 safety classification, and zero ozone depletion potential for applicable refrigeration end uses. R404A is commonly listed at a GWP of 3,922. On that basis, R448A has approximately 65% lower GWP than R404A. Review the EPA SNAP listing for remote condensing units.

What Is R404A?

R404A is a zeotropic HFC blend composed of R125, R143a, and R134a. It became widely used in supermarket racks, display cases, ice machines, walk-in coolers, freezers, and other low- and medium-temperature refrigeration equipment.

It is nonflammable under its A1 safety classification and has zero ozone depletion potential. However, its high GWP has made it a target of refrigerant-transition policies and equipment restrictions.

R404A is still found in a large installed base. Its presence in an existing system does not automatically mean that the equipment must immediately be converted. Service availability, leak history, equipment condition, regulatory requirements, energy use, and the remaining life of the system should all influence the decision. See Honeywell’s R404A technical properties.

What Is R448A?

R448A is a five-component HFO/HFC blend developed for low- and medium-temperature commercial refrigeration. It contains R32, R125, R134a, R1234yf, and R1234ze(E).

Like R404A, it carries an A1 safety classification. However, its considerably lower GWP makes it an option for certain new systems and approved R404A retrofit projects.

R448A is commonly associated with supermarket refrigeration, refrigerated display cases, condensing units, food-service equipment, cold storage, and other commercial applications. It is not intended as a general-purpose substitute for every system that currently contains R404A.

Honeywell describes R448A as a reduced-GWP option for new supermarket installations and retrofits of qualifying R404A systems, particularly in low- and medium-temperature refrigeration. Review Honeywell’s current R448A product information.

How Does R448A Performance Compare With R404A?

Cooling Capacity

R448A is designed to provide capacity relatively close to R404A in many commercial refrigeration applications. That does not mean capacity will be identical in every system.

Evaporating temperature, condensing temperature, compressor design, heat-exchanger size, control settings, refrigerant charge, and expansion-device selection can all affect the result. Manufacturer software and model-specific application data should be used before assuming equivalent performance.

Energy Efficiency

Manufacturer testing and field reports indicate that R448A can provide efficiency improvements over R404A under certain operating conditions. Honeywell reports that R448A can match R404A capacity while reducing energy consumption in some supermarket retrofits.

These results should not be treated as a universal guarantee. A poorly commissioned conversion may lose efficiency even when the refrigerant itself is capable of good performance. See Honeywell’s R448A retrofit performance information.

Compressor Discharge Temperature

R448A can produce higher compressor discharge temperatures than R404A, particularly in low-temperature applications.

The contractor must verify the compressor operating envelope and determine whether liquid injection, vapor injection, demand cooling, or another discharge-temperature control method is required. Running outside the approved envelope can reduce oil stability, overheat the compressor, and shorten equipment life.

Why Temperature Glide Matters

R448A has substantially more temperature glide than R404A. During evaporation or condensation, its temperature changes as the blend changes phase at a constant pressure.

Technicians must therefore work with the correct pressure-temperature values:

• Use the refrigerant’s dew-point value when calculating superheat.
• Use the bubble-point value when calculating subcooling.
• Follow manufacturer guidance when setting control points affected by average evaporating or condensing temperature.

Using the wrong value can produce incorrect superheat or subcooling readings. That may lead to undercharging, overcharging, poor evaporator feeding, floodback, or excessive compressor temperatures.

Expansion valves, evaporator pressure regulators, low-pressure controls, and electronic controllers may require adjustment after the conversion. Honeywell’s retrofit guide specifically distinguishes dew, bubble, and average values for systems using moderate-glide blends. Consult the Honeywell R448A retrofit technical guide.

Can R448A Directly Replace R404A?

No. R448A should not be poured into an R404A system as though the two products were interchangeable.

A conversion should proceed only when the compressor, expansion device, controls, seals, lubricant, and other system components are approved or determined suitable by the relevant manufacturers.

R448A and R404A must not be mixed. Adding R448A on top of an existing R404A charge creates an unidentified mixture with unpredictable pressure-temperature behavior and performance. It also complicates future recovery and reclamation.

Before selecting either refrigerant, contractors and equipment owners can compare the available R448A refrigerant and R404A refrigerant options at Get Freon. Product selection should follow OEM compatibility confirmation—not replace it.

R404A-to-R448A Retrofit Procedure

The exact procedure depends on the equipment and manufacturer instructions. A typical professional conversion includes the following steps.

1. Confirm Equipment Approval

Check the compressor model, condensing unit, expansion valve, control system, and equipment manufacturer documentation. Confirm that R448A is approved for the intended operating range.

Do not rely solely on similar pressures or general retrofit claims.

2. Record Baseline Performance

Operate the R404A system and record:

• Suction and discharge pressures
• Superheat and subcooling
• Refrigerant charge weight
• Box or case temperatures
• Compressor amperage
• Discharge temperature
• Ambient and liquid temperatures
• Existing control settings

Repair known leaks while the original refrigerant is still in the system so that baseline readings remain meaningful.

3. Recover the Complete R404A Charge

Recover the R404A using approved equipment and a properly identified recovery cylinder. Do not vent the refrigerant, and do not place it into a cylinder containing a different refrigerant.

Weigh and document the recovered charge. The old refrigerant should be recycled, reclaimed, or otherwise handled in accordance with applicable regulations.

4. Inspect Components and Lubricant

Many R404A and R448A applications use POE lubricant, but oil compatibility must still be confirmed for the specific compressor. Check the oil level and condition after the system has stabilized.

Replace the filter-drier during the retrofit. Inspect seals, O-rings, valve packing, and other potential leakage points. Expansion-valve adjustment or replacement may be necessary.

5. Leak-Test and Evacuate the System

After completing component work, leak-test the system using approved procedures. Evacuate it to the level specified by the equipment or refrigerant manufacturer.

Air and moisture can cause high operating pressures, oil degradation, acid formation, and reduced reliability.

6. Charge R448A as a Liquid

Because R448A is a zeotropic blend, it should be transferred from the cylinder in the liquid phase to preserve its intended composition. Liquid must be introduced in a controlled manner to prevent compressor damage.

Copeland’s changeover guidance for covered systems recommends starting at approximately 80% of the original R404A charge by weight and then adjusting based on operating conditions. This is a commissioning starting point—not a universal final-charge specification.

7. Adjust and Verify Operation

After startup:

• Set superheat using dew-point data.
• Determine subcooling using bubble-point data.
• Adjust pressure controls and regulators where necessary.
• Verify expansion-valve operation.
• Monitor compressor amperage and discharge temperature.
• Confirm stable case, box, and product temperatures.
• Check the compressor operating envelope.
• Add refrigerant only in carefully measured increments.

Copeland also warns against mixing refrigerants and identifies control adjustment, filter-drier replacement, liquid charging, and system relabeling as important parts of a proper conversion. Review Copeland’s refrigerant changeover guide.

8. Relabel and Document the System

The equipment label should clearly identify:

• R448A as the installed refrigerant
• Final charge weight
• Lubricant type and quantity
• Retrofit date
• Control changes
• Components replaced
• Technician or service company information

Complete documentation prevents accidental mixing and gives future technicians an accurate service history.

Should You Keep R404A or Convert to R448A?

Keeping R404A may be reasonable when:

• The system is reliable and has a low leak rate.
• The equipment is near the end of its useful life.
• The compressor or major components are not approved for R448A.
• Retrofit costs would exceed the remaining value of the equipment.
• A complete equipment replacement is already planned.

An R448A retrofit may be worth evaluating when:

• The equipment is in good mechanical condition.
• The system has many years of expected service remaining.
• The compressor and components are approved.
• Reducing the system’s refrigerant-related climate impact is a priority.
• R404A supply and service costs create operational concerns.
• Documented energy performance supports the investment.

For multiple systems, a refrigerant-management plan is usually more effective than making isolated replacements. Track refrigerant inventory, annual leak rates, equipment age, service costs, retrofit eligibility, and replacement schedules across the entire facility.

Regulatory Considerations

U.S. refrigerant restrictions depend on the equipment category, installation date, refrigerant GWP, and specific end use. High-GWP refrigerants face increasing restrictions in new equipment, but this does not mean every operating R404A system became illegal on a single nationwide date.

The EPA Technology Transitions program establishes different GWP limits and compliance dates for various refrigeration subsectors. In some categories, R448A may be an acceptable transition option; in others, future limits may require refrigerants with an even lower GWP.

For that reason, R448A should not automatically be described as “future-proof.” Contractors and equipment owners should confirm the rule applicable to the exact equipment category and project date. Check the EPA’s current sector-based HFC restrictions.

Frequently Asked Questions

Is R448A a drop-in replacement for R404A?

No. R448A may be a retrofit option for certain approved systems, but charging procedures, controls, expansion devices, and compressor protection may require changes.

Can R448A and R404A be mixed?

No. The original R404A charge should be completely recovered before R448A is introduced. Mixing creates unpredictable performance and complicates refrigerant recovery.

Does R448A use the same oil as R404A?

Both refrigerants commonly use POE lubricant in compatible commercial refrigeration systems. However, lubricant type and viscosity must be confirmed for the specific compressor.

Is R448A more efficient than R404A?

It can be more efficient in some properly designed or retrofitted systems. Actual performance depends on equipment design, operating temperatures, commissioning, controls, and maintenance.

Can the same expansion valve be used?

Sometimes, but not automatically. The existing valve may require adjustment, a different power element, or replacement. The valve manufacturer’s capacity and refrigerant data should be checked.

Is R404A banned in the United States?

R404A is subject to restrictions in certain new refrigeration equipment and applications. Existing systems may generally continue operating and being serviced, subject to applicable federal and state requirements.

Is R448A suitable for residential air conditioning?

R448A is primarily intended for certain commercial refrigeration applications. It should not be used in residential air-conditioning equipment unless the equipment manufacturer specifically approves it—which is uncommon.

Final Takeaway

R448A offers substantially lower GWP than R404A and can deliver comparable capacity with possible efficiency benefits in approved commercial refrigeration systems. Its greater temperature glide, different charge requirements, and potentially higher discharge temperatures make careful commissioning essential.

A sound replacement decision begins with the compressor and equipment manufacturers—not the refrigerant cylinder. Confirm compatibility, recover the complete R404A charge, install or adjust required components, charge R448A as a liquid, use the correct bubble and dew values, and document the finished conversion.

When those steps cannot be completed or the equipment is approaching retirement, continuing to maintain the existing R404A system—or planning a complete equipment replacement—may be more practical than retrofitting.