If you’re replacing R22, R438A is one of the easiest drop-in options. It works with your existing system and avoids major changes. Before you change your system, you should figure out if R438A is the right fit for your R22 system.
In this guide, you’ll learn what R438A refrigerant is, R438A refrigerant properties, and which refrigerants R438A can replace.
What is R438A Refrigerant?
R438A is an HFC blend designed as a direct replacement for R22. It has zero ozone depletion potential (ODP) and works with most existing systems without major changes.
It’s made from R125 (45%), R134a (44.2%), R32 (8.5%), R600 (1.7%), and R600a (0.6%). This blend lets it run very close to R22, without ozone impact.
Properties of R438a Refrigerant
Physical Properties
R438A has a low boiling point, enabling it to maintain excellent cooling performance in low-temperature environments.
What matters is how pressure and temperature affect how your system runs. R438A has moderate critical parameters, allowing it to operate stably in most refrigeration systems. These properties help your system move heat faster and keep cooling stable.
R438A belongs to the zeotronic blend. It must be filled with liquid.
Here are the physical properties of R438a:
| Physical Properties | R438A |
| Refrigerant Classification | HFC |
| Molecular Weight | 99.099 |
| Boiling Point (1atm,℃) | -45.9 |
| Critical Pressure (bar) | 46.6 |
| Critical Temperature (℃) | 83.7 |
| Critical Density (lb./ftˆ3) | 1150.81 |
| Liquid Density (70˚F, lb./ftˆ3) | 71.6 |
| Vapor Density (bp.lb./ftˆ3) | 72.7 |
| Heat of Vaporization (bp, BTU/lb.) | 69.6 |
| Specific Heat Liquid (70 ˚F, BTU/lb. ˚F) | 348 |
| Specific Heat Vapor (1atm, 70 ˚F, BTU/lb. ˚F) | 0.253 |
| ODP | 0 |
| GWP (IPCC) | 2,265 (AR4) |
| Safety Standard | A1 |
| Oil | Mineral Oil (MO), Alkylbenzene (AB), and Polyolester (POE) |
| Temperature Glide | ~4.9K |
Chemical Properties
R438A refrigerant can operate reliably in refrigeration systems over long periods without decomposing or deteriorating. It is stable and works well with common oils like MO, AB, and POE. That means you usually don’t need to change the lubricant during retrofit.
R438A has zero ODP, but it still has a relatively high GWP compared to newer low-GWP refrigerants. Even with a higher GWP, many systems still use R438A because it’s easy to retrofit.
Pressure Temperature Chart
| R438A (PSIG) | ℉ | ℃ |
| 1.7 | -40 | -40 |
| 3.9 | -35 | -37.2 |
| 6.4 | -30 | -34.4 |
| 9.1 | -25 | -31.7 |
| 12 | -20 | -28.9 |
| 15.3 | -15 | -26.1 |
| 18.8 | -10 | -23.3 |
| 22.7 | -5 | -20.6 |
| 26.8 | 0 | -17.8 |
| 31.4 | 5 | -15 |
| 36.3 | 10 | -12.2 |
| 41.6 | 15 | -9.4 |
| 47.2 | 20 | -6.7 |
| 53.4 | 25 | -3.9 |
| 59.9 | 30 | -1.1 |
| 66.9 | 35 | 1.7 |
| 74.4 | 40 | 4.4 |
| 82.6 | 45 | 7.2 |
| 91 | 50 | 10 |
| 100.1 | 55 | 12.8 |
| 109.7 | 60 | 15.6 |
| 120.2 | 65 | 18.3 |
| 131 | 70 | 21.1 |
| 142.5 | 75 | 23.9 |
| 154.6 | 80 | 26.7 |
| 167.5 | 85 | 29.4 |
| 181.3 | 90 | 32.2 |
| 195.6 | 95 | 35 |
| 210.7 | 100 | 37.8 |
| 226.6 | 105 | 40.6 |
| 243.3 | 110 | 43.3 |
| 260.8 | 115 | 46.1 |
| 279.2 | 120 | 48.9 |
| 298.5 | 125 | 51.7 |
| 318.7 | 130 | 54.4 |
| 339.8 | 135 | 57.2 |
| 361.9 | 140 | 60 |
| 385 | 145 | 62.8 |
| 409 | 150 | 65.6 |
Advantages of R438A Refrigerant
High-Efficiency Cooling
In most refrigeration systems, R438A delivers cooling capacity and efficiency very close to that of R22, especially in low-temperature applications. R438A can even provide up to 8% higher cooling capacity and 16% greater efficiency than R22.
Extended Compressor Life
R438A refrigerant has a lower discharge temperature than R22, which helps extend the service life of the compressor. By lowering the discharge temperature, R438A reduces the risk of compressor damage due to overheating, thereby improving the reliability of the system and durability.
Easy Retrofit
You can retrofit to R438A refrigerant without changing oil, valves, or major components. It reduces time, labor, and system issues. You can retrofit the refrigerant easily without problems.
Strong Compatibility
R438A is compatible with a wide range of lubricants, including traditional mineral oils and newer ester-based lubricants. During the conversion process, there is no need to change the type of lubricant. You can change your system in this way to simplify the retrofit process and lower costs.
R438A is also compatible with various refrigeration equipment and system designs. It makes it suitable for a broader range of applications.
Drawbacks of R438A Refrigerant
Relatively High Cost
The cost of R438A refrigerant is higher than that of some refrigerants. But you may offset that with lower retrofit costs. You should weigh the higher cost against the lower retrofit expense.
Professional Operation
Although the process of conversion for R438A is relatively simple, it still requires operation by qualified technicians. This is because the conversion of a refrigeration system involves multiple steps. They include refrigerant recovery, charging, and system commissioning. It requires specific professional knowledge and skills. Non-professional personnel operation may lead to system failure or safety accidents.
Where You Can Use R438A refrigerant?
- Residential and commercial air conditioning systems: rooftop units, split-system units, direct expansion chillers
- Medium- and low-temperature commercial refrigeration equipment: food service refrigeration, supermarket display cases, food storage, and processing
- Industrial systems: R22 industrial chillers, air-source heat pumps, dehumidifiers, and industrial cooling equipment
Which Refrigerants Can R438A Replace?
In most systems, no oil change is required by using R438A. So you can use R438A refrigerant to replace other refrigerants.
R22
The primary target for R438A refrigerant is the traditional R22 refrigerant. R22 is being phased out due to its ozone-depleting properties, while R438A has become an ideal replacement for R22 because of its less environmental impact, including zero ODP and low GWP. In most refrigeration systems, R438A provides cooling capacity and efficiency very close to that of R22, while simplifying the retrofit process and saving costs.
R407C, R410A (in certain applications)
R407C and R410A were early alternatives to R22. However, R407C requires the use of POE oil, making retrofits complex. R410A operates at pressures 50% higher than R22, necessitating the replacement of compressors and heat exchangers, which results in high retrofit costs.
R438A refrigerant can serve as an indirect replacement for R407C and R410A in both air conditioning and medium-temperature refrigeration applications. It is a particularly good fit for systems currently using R407C that require simplified maintenance, or for R410A equipment where pressure is too high and requires a pressure-reduction retrofit. You do not need to replace core parts and can reduce retrofit costs.
However, please note that R410A is a high-pressure refrigerant, while R438A operates at lower pressures. After changing your system, the expansion valve opening must be adjusted to prevent insufficient cooling capacity.
R404A, R507A (Medium-Temperature Applications)
R404A and R507A are commonly used refrigerants for medium- and low-temperature refrigeration, but with a GWP of 3,922. They have an extremely high global warming potential and have been restricted in regions such as the EU by EU Regulation 517/2014. R438A can partially replace R404A and R507 in medium-temperature refrigeration applications. It provides the cooling capacity while having a lower global warming potential. However, in low-temperature applications, R438A performs worse than R404A and R507. So R438A cannot replace them completely. It is only suitable for retrofits in medium-temperature scenarios.
R438A vs R22
| Property | R22 | R438A |
|---|---|---|
| ODP | 0.055 | 0 |
| GWP | 1810 | 2265 |
| Safety Class | A1 | A1 |
| Oil Change Required | Sometimes | Usually No |
| Retrofit Difficulty | — | Easy |
How to Retrofit an R22 System to R438A?
Step 1
Recover the existing R22 refrigerant.
Step 2
Replace filter driers and inspect seals.
Step 3
Check lubricant condition.
Step 4
Charge R438A in the liquid phase.
Step 5
Adjust superheat and verify system performance.
Substitution Precautions
R438A refrigerant cannot replace refrigerants such as R134a, R123, or R290.
- R134a is a low-pressure refrigerant, whereas R438a operates at higher pressures; substituting it would cause system pressure to exceed specifications.
- R123 is a low-pressure HCFC refrigerant used in centrifugal chillers. R438a is poorly compatible with the systems.
- R290 is a natural refrigerant that is flammable. Because of differences in safety ratings, it cannot be directly replaced. Before you switch, check your system, oil type, and operating conditions. It avoids equipment failure caused by improper replacement.
To Wrap Up
Whether in residential air conditioning, commercial refrigeration equipment, or air-source heat pump water heaters, R438A refrigerant delivers stable and reliable cooling performance.
If you are looking for an environmentally friendly and efficient refrigerant to replace traditional R22 or other high-GWP refrigerants, R438A refrigerant is a worthy option to consider.
FAQ
Is R438A a drop-in replacement for R22?
Yes. You can switch to R438A refrigerant without major changes in most systems.
Can you mix R438A with R22?
No. When upgrading the original R22 system, it is necessary to first completely recover the R22 from the original system. You should perform system leak detection, repair, and vacuum treatment, and then fully charge R438A. But in the later maintenance of R438A’s own system, it is allowed to directly add R438A (requiring liquid filling).
Do you need to change oil when using R438A?
No. It works with mineral oil, AB, and POE.
Is R438A easier to use than R407C?
R438A is easier to retrofit, but fR407C may have better efficiency in some systems.
Can R438A replace R410A?
Not directly. R410A systems run at much higher pressure.
Is R438A still being used?
Yes, but some regions are reducing high-GWP refrigerants.
Is R438A still a good choice in 2026?
Yes. If your goal is to keep an existing R22 system running reliably, R438A remains a good choice. If you are planning a new installation or looking for a long-term low-GWP solution, refrigerants such as R454A, R452A, or R448A may be better options depending on your application.
You may also find this related blog post very useful:
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