R407A and R404A are both A1 HFC refrigerants that technicians may encounter in medium- and low-temperature refrigeration, but they are not interchangeable simply because they can appear in similar applications. R404A became widely used in supermarket racks, freezers, walk-ins, and other commercial refrigeration equipment. R407A has been used in selected new installations and retrofits where the equipment, compressor, oil, controls, and expansion devices support it.

If you are asking “How does R407A compare to R404A in refrigeration systems?”, the practical answer is that R407A can offer a lower global warming potential and can be a useful option in approved applications, but it behaves differently from R404A. The blend composition, temperature glide, pressure-temperature interpretation, charging procedure, and retrofit requirements all matter. The correct choice starts with the equipment documentation rather than with a simple assumption that one refrigerant can replace the other.

R407A vs R404A at a Glance

How does R407A compare to R404A in refrigeration systems? The quickest way to understand the difference is to compare their chemistry, environmental profile, and service behavior before looking at application-specific details.

R407A Has a Different Blend Composition

R407A is a zeotropic blend of R32, R125, and R134A. Arkema’s current Forane R407A technical information lists the blend at 20% R32, 40% R125, and 40% R134A by mass. That composition creates temperature glide, which means the refrigerant does not evaporate and condense at one single saturation temperature throughout a phase change.

R404A uses a different blend based primarily on R125 and R143A with a smaller percentage of R134A. It behaves much closer to an azeotropic refrigerant than R407A, so its glide is comparatively small. For technicians, this distinction changes how pressure-temperature data should be read and how superheat and subcooling are calculated.

Both Are A1, but A1 Does Not Mean Risk-Free

Both refrigerants carry an A1 safety classification, meaning lower toxicity and no flame propagation under the applicable classification test. That does not remove normal refrigerant-service hazards. Both products are stored under pressure, liquid contact can cause frostbite, vapor can displace oxygen in poorly ventilated areas, and cylinders can become dangerous if exposed to excessive heat.

Professional handling should still include appropriate PPE, ventilation, compatible recovery equipment, clearly identified recovery cylinders, leak control, and compliance with EPA and local requirements.

Environmental Impact and 2026 Regulatory Planning

The environmental difference is one of the biggest reasons R407A entered conversations about replacing or reducing dependence on R404A. However, buyers should avoid treating “lower GWP” as the same thing as “low GWP.”

R407A Has a Lower GWP Than R404A

Arkema’s Forane R407A literature describes R407A as having a carbon footprint substantially below R404A and R507A. Older AR4 references commonly place R407A around a GWP of 2,107 and R404A around 3,922. The exact value used for regulation or reporting can depend on the reference framework, so current regulatory tables should be checked rather than relying on an old sales sheet.

The practical point is unchanged: R407A is materially lower than R404A, but it is still an HFC blend with a GWP high enough to matter in long-term equipment planning.

Neither Refrigerant Is a Universal New-Equipment Choice in 2026

Current EPA Technology Transitions rules set sector-specific GWP limits for new refrigeration equipment. Those limits vary by application, charge size, and compliance date. For example, current EPA tables include limits below the GWP of both R407A and R404A for several cold-storage and retail-food subsectors. That means a refrigerant can remain useful for servicing legacy equipment while no longer being appropriate for certain new installations.

Before specifying either product for new equipment, review the current EPA HFC restrictions by sector, the equipment manufacturer’s approved refrigerants, and applicable state requirements. For existing systems, service rules and the system’s original design still need to be considered separately from new-equipment restrictions.

Performance in Medium- and Low-Temperature Refrigeration

Performance should be evaluated at the actual evaporating and condensing conditions of the equipment. A refrigerant that performs well in one supermarket rack may not be the best fit for another compressor, valve, or application temperature.

R404A Has a Large Installed Base

R404A became a standard refrigerant for many legacy commercial refrigeration systems, including supermarket display cases, walk-ins, freezers, ice machines, and other medium- and low-temperature applications. That installed base means service technicians often already know the expected pressure-temperature behavior, charge procedures, controls, and compressor characteristics of R404A equipment.

Royal Refrigerants’ R404A guide provides additional context on where the refrigerant has traditionally been used and why alternative planning has become more important.

R407A Can Work Well in Approved Refrigeration Applications

R407A is positioned by manufacturers for medium- and low-temperature refrigeration, including supermarket refrigeration, refrigerated storage, food processing, and selected transport applications. National Refrigerants describes R407A as having properties similar to R22 at lower evaporator temperatures, while Arkema positions it as a replacement option for R404A and R507A in suitable equipment.

That does not mean every R404A system should be converted to R407A. Capacity, mass flow, discharge temperature, valve sizing, oil return, compressor operating envelope, and controls should all be checked using current manufacturer guidance.

Temperature Glide Is a Major Service Difference

One of the most important field differences between these refrigerants is how strongly temperature glide affects diagnosis and charging.

R407A Requires Dew and Bubble Awareness

Because R407A is zeotropic, technicians need to distinguish between bubble-point and dew-point saturation temperatures. Dew temperature is generally relevant to vapor-side superheat calculations, while bubble temperature is generally used for liquid-side subcooling. Using a single saturation value can introduce diagnostic errors.

Modern digital manifolds can simplify this calculation, but the technician still needs to select R407A correctly and understand what the displayed value represents.

R404A Is Less Sensitive to Glide in Routine Service

R404A is a near-azeotropic blend, so its temperature glide is much smaller. Technicians still need accurate pressure-temperature data, but the difference between dew and bubble values is less pronounced than with R407A.

This is one reason a technician accustomed to R404A should not approach R407A service as though the two products behave identically.

Charging and Leak-Service Procedures Are Not the Same

Both refrigerants are blends, and both should be handled according to manufacturer instructions. R407A’s stronger zeotropic behavior makes blend composition especially important during charging and leak service.

R407A Should Be Charged as Liquid

Arkema’s Forane R407A technical guide instructs technicians to charge the refrigerant as liquid. Liquid withdrawal helps maintain the intended blend composition instead of preferentially removing more volatile components from a cylinder.

When an approved procedure requires introducing refrigerant through the suction side, liquid should be metered in a controlled manner so that the compressor does not receive an uncontrolled liquid slug.

Significant Leaks Require More Than a Quick Top-Off

After a major refrigerant loss, technicians should determine whether the remaining blend composition may have shifted and follow the refrigerant and equipment manufacturer’s service procedure. A leak repair should include finding the source of the loss, repairing it, testing the system where required, evacuating correctly, and restoring the specified charge by weight.

Repeatedly adding refrigerant without repairing a leak can hide the actual problem and increase operating cost.

Can R407A Replace R404A?

R407A can be used as an R404A replacement in some approved medium- and low-temperature refrigeration applications, but the conversion should be treated as a retrofit project, not as a simple cylinder swap.

Check the Compressor and OEM Retrofit Guidance

Start with the compressor model and the equipment manufacturer. Verify that R407A is approved across the expected suction and condensing conditions. Review capacity, discharge temperature, motor loading, oil recommendations, and any envelope restrictions.

If the compressor or equipment manufacturer does not support the conversion, pressure similarity is not enough justification to proceed.

Review Expansion Devices, Controls, and Charge Amount

A retrofit may require changes to thermostatic expansion valve settings or components, superheat targets, pressure controls, receiver levels, defrost controls, and the final refrigerant charge. R407A and R404A have different density and flow characteristics, so the old R404A charge weight should not automatically become the R407A target.

Record the completed conversion on the equipment and in service documentation so the next technician does not mistake the system for an unchanged R404A installation.

Oil Compatibility and System Cleanliness Matter

Lubricant compatibility is another area where shortcuts can create repeat failures. Both R404A and R407A systems commonly use POE oil, but that does not mean every existing oil charge is automatically suitable.

Confirm the Exact POE Grade

POE is a category, not a single lubricant. Compressor manufacturers specify viscosity and approved lubricant families. A retrofit should verify the existing oil, its condition, and the compressor manufacturer’s requirements rather than assuming that any POE oil is acceptable.

POE is also hygroscopic, meaning it absorbs moisture readily. Keep oil containers sealed, minimize the time the system is open, replace driers when required, and pull the specified vacuum after repairs.

Do Not Mix Refrigerants

Never use R407A as a casual “top-off” over R404A. Mixed refrigerants can create unpredictable pressure-temperature relationships, alter capacity and oil return, contaminate recovery equipment, and make future reclamation more difficult.

Recover the original refrigerant according to the approved retrofit procedure before introducing the new product.

R407A vs R404A for Existing-System Decisions

The best decision depends on whether the goal is to keep a functioning legacy system operating, repair a major failure, or invest in a longer-term transition.

Continuing With R404A May Make Sense for a Healthy Legacy System

If an existing R404A system is mechanically sound, has a manageable leak history, and can be legally serviced, continuing with the specified refrigerant can sometimes be less disruptive than converting it immediately. Retrofit labor, control changes, oil management, commissioning, and downtime all have costs.

However, owners should also consider refrigerant availability, future repair frequency, equipment age, energy performance, and regulatory direction rather than evaluating only today’s cylinder price.

R407A Can Be a Bridge in Approved Applications, Not a Final Answer for Every Facility

R407A can reduce GWP relative to R404A and may extend the useful life of selected equipment, but newer refrigerants such as R448A and R449A can offer substantially lower GWP in many commercial refrigeration applications. New equipment may use still lower-GWP technologies depending on the application.

For facilities with multiple systems, create a refrigerant transition plan instead of making each repair decision in isolation. Categorize equipment by refrigerant, age, charge size, leak history, remaining useful life, and replacement timeline.

Frequently Asked Questions

These concise answers cover the most common field and purchasing questions about R407A and R404A.

Is R407A the Same as R404A?

No. They have different blend compositions, different temperature-glide characteristics, and different service behavior. They should never be mixed.

Is R407A Lower GWP Than R404A?

Yes. R407A has a materially lower GWP than R404A, although it is still an HFC with a GWP high enough to face restrictions in some new-equipment applications.

Can R407A Be Used in an R404A System?

Only when the equipment and compressor manufacturers or an approved retrofit procedure support the conversion. It is not a universal drop-in replacement.

Does R407A Use POE Oil?

Typically yes. The exact lubricant type and viscosity must still match the compressor manufacturer’s requirements.

Which Refrigerant Has More Temperature Glide?

R407A. Technicians should use the correct dew and bubble saturation values when calculating superheat and subcooling.

Is R404A Still Allowed in Existing Equipment?

Existing equipment can often continue to be serviced, but federal and state rules vary by activity and application. New-equipment restrictions are more stringent, so current EPA and local requirements should be checked before planning a project.

Conclusion: Make the Decision Around the Equipment

R407A can offer a lower-GWP path than R404A in selected medium- and low-temperature refrigeration systems, but the choice cannot be made from refrigerant names alone. Temperature glide, compressor approval, expansion-device behavior, charge quantity, oil, controls, regulatory limits, and equipment life all belong in the decision.

If you have a specific refrigeration system and need help sourcing the refrigerant that its documentation calls for, contact Royal Refrigerants with the equipment type, current refrigerant, cylinder quantity, and service timeline. That makes it easier to confirm product availability without turning a technical compatibility decision into a guess.