In HVAC/R engineering, a true "drop-in" refrigerant means you can replace an old gas with a new one without changing any hardware, metering devices, or oil. By strict definition, no true drop-in exists. However, the industry uses specific "near drop-in" retrofits with minimal to no oil/hardware changes:
Comstar RS-44b is the closest, market available drop-in replacement for R22 that requires no oil changes and no system changes. Other features include: Equal Flow Rate & Cooling Capacity as R22.
While R-407C is the closest match to R-22 in terms of pressures and cooling capacity, it is not a true "drop-in" replacement. You cannot simply pour it into an existing R-22 system without professional modifications and a full evacuation.
The only non-flammable "drop-in" (retrofit) replacement for R410A in existing HVAC systems is R-470A (sold by ComStar under the name RS-53). It drops into existing R410A systems with a roughly 56% lower Global Warming Potential (GWP) and requires no oil or component changes.
No, R-454B is not a drop-in replacement for R-410A. You cannot retrofit or mix them in the same system.
RS-53 (R470A) is a new non-flammable Drop-in replacement for R410A with a low Global Warming Potential (GWP) less than half that of R410A.
Yes, but only for specific commercial refrigeration systems. R-407A is widely used as a retrofit to replace R-22 in low- and medium-temperature commercial equipment (like walk-in coolers and supermarket cases). However, it is not intended or approved for residential air conditioning.
While marketing often claims certain products are "drop-in" replacements, there are no true, zero-effort "drop-in" replacements for R-22 that maintain identical performance without any modifications. Retrofitting requires careful, professional procedures, including changing oil types or replacing components to ensure system longevity and efficiency.
A2L refrigerants, the new refrigerants for 2026, will replace R-410A in new systems. A lot about A2L refrigerants is explained in their name: The “A” means low toxicity. The “2L” is a safety classification, indicating it is mildly flammable.
R422B can be used to COMPLETELY replace R-22 refrigerant in new or existing R-22 residential and commercial air conditioning systems as well as non-flooded evaporator chillers. Cannot be added to R-22 unless fully evacuated and recharged with 422B.
It is concluded that R458A performs well as a drop-in alternative refrigerant to R22 and surpasses that of R453A, as it showed slightly less deviation in coefficient of performance.
Yes, MO99 (formally known as R-438A) is widely used as a direct "drop-in" replacement for R-22 in existing air conditioning and refrigeration systems.
R22 Drop In Replacement Refrigerant
RS-44b has been sold worldwide for the past 8 years, branded as RS-70 outside the US. It is the closest replacement to R22 that operates with very similar discharge pressure, cooling capacity, and flow rate as R22.
Trying to use R-454B in a system built for R22 or 410A can cause leaks, breakdowns, and even void your warranty. Even if it were technically possible, retrofitting usually ends up costing as much as replacing the system outright — but without the efficiency or reliability of a new unit.
No. R134a operates at different pressures and has lower capacity than R22, making it unsuitable as a direct replacement in most systems.
While R-407C is the closest match to R-22 in terms of pressures and cooling capacity, it is not a true "drop-in" replacement. You cannot simply pour it into an existing R-22 system without professional modifications and a full evacuation.
R-427A is not a true "drop-in" replacement. While it is an excellent R-22 retrofit that doesn't require replacing expansion valves or other hardware, it cannot simply be mixed with existing R-22.
Freon MO99 is the gold standard for R-22 alternatives and was developed by the same scientists who engineered Freon R-22. The benefits of Freon MO99 include: Capacity — The ability of Freon MO99 to heat or cool a given space is closer to Freon R-22 than any other refrigerant on the market.
Freon™ 407C exhibits similar performance to HCFC-22 at air conditioning conditions, while Freon™ 407A exhibits similar performance to R-404A with lower capacity at low and medium temperature refrigeration conditions.
Yes, NU-22B is a direct drop-in replacement for R-22. It is compatible with most existing R-22 components and oils.
R-407C is most commonly used as a direct retrofit (drop-in) replacement for R-22 in residential and commercial air conditioning and heat pump systems. However, it is not a direct "drop-in" in the truest sense, as it typically requires completely flushing out the system's mineral oil and replacing it with synthetic Polyolester (POE) oil.
No, R-454B is not a drop-in replacement for R-410A. You cannot retrofit or mix them in the same system.
Finding a direct, zero-modification "drop-in" replacement for R-12 depends on your system type, but R-409A is the most common true drop-in for stationary commercial refrigeration, while R-134a (with conversion fittings) or hydrocarbon blends are popular for automotive applications. These alternatives require little to no flushing or oil changes.
January 1, 2025: Manufacturers stopped producing new R-410A residential split systems and heat pumps. Equipment manufactured before this date can still be sold and installed. January 1, 2026: The original deadline for installing R-410A split systems manufactured before 2025.