HFC refrigerants (hydrofluorocarbons) replaced ozone-depleting CFC and HCFC refrigerants across the global HVAC/R industry. However, HFC refrigerants introduced a critical engineering challenge: they are immiscible with traditional mineral oils. Using an incompatible lubricant in an HFC system causes oil logging in evaporators, compressor oil starvation, bearing wear, and premature system failure.
The correct lubricant must be fully miscible with the refrigerant across the entire operating temperature range — from evaporator temperatures as low as -40°C to compressor discharge temperatures exceeding 120°C. This guide provides a complete refrigeration oil HFC compatibility reference for the five most widely used HFC refrigerants.
For a found POE and mineral oil properties, see our guide: POE Oil vs Mineral Oil: Which Refrigeration Lubricant Should You Choose?
The following matrix summarizes lubricant compatibility for all major HFC refrigerants. POE (polyol ester) oil is the required lubricant for HFC systems. Mineral oil and alkylbenzene (AB) oil are not compatible.
| HFC Refrigerant | POE Oil | Mineral Oil | Alkylbenzene (AB) Oil | Recommended Viscosity |
|---|---|---|---|---|
| R-134a | Compatible | Not Compatible | Not Compatible | ISO VG32 – VG68 |
| R-404A | Compatible | Not Compatible | Not Compatible | ISO VG32 – VG68 |
| R-407C | Compatible | Not Compatible | Not Compatible | ISO VG32 – VG68 |
| R-410A | Compatible | Not Compatible | Not Compatible | ISO VG32 – VG46 |
| R-507A | Compatible | Not Compatible | Not Compatible | ISO VG32 – VG68 |
Key finding: All HFC refrigerants require POE oil. Mineral oil and alkylbenzene oil are incompatible with every HFC refrigerant due to fundamental differences in molecular polarity. HFC molecules are polar; mineral and AB oils are non-polar. Only POE oil provides the polar molecular structure needed for full miscibility with HFC refrigerants.
R-134a is the most widely used HFC refrigerant in medium-temperature commercial refrigeration, automotive air conditioning, and centrifugal chillers. It operates at moderate pressures and is a single-component (pure) refrigerant.
R-134a has zero ozone depletion potential (ODP) and a GWP of 1430. It remains the dominant refrigerant in centrifugal chillers and automotive AC systems worldwide.
R-404A is a ternary HFC blend (R-125/R-143a/R-134a) used primarily in low-temperature and medium-temperature commercial refrigeration: supermarket display cases, cold storage, transport refrigeration, and ice machines.
R-404A has a high GWP (3922) and is being phased down under the Kigali Amendment. Replacement refrigerants (R-448A, R-449A, R-452A) also require POE oil.
R-407C is a ternary HFC blend (R-32/R-125/R-134a) designed as a retrofit replacement for R-22 in air conditioning and medium-temperature refrigeration. It has a significant temperature glide (approximately 5-7°C), which affects system design.
When retrofitting R-22 systems to R-407C, the mineral oil must be removed and replaced with POE oil. A minimum of three oil flushes is recommended to achieve less than 5% residual mineral oil concentration.
R-410A is a near-azeotropic HFC blend (R-32/R-125, 50/50 by weight) that operates at approximately 60% higher pressure than R-22. It is the dominant refrigerant in residential and commercial air conditioning systems nufactured after 2010.
R-410A systems are factory-designed for POE oil. Mineral oil must never be introduced into an R-410A system — even trace amounts (above 1%) will cause oil return failure and compressor damage.
R-507A is an azeotropic HFC blend (R-125/R-143a, 50/50 by weight) used in low-temperature commercial refrigeration as an alternative to R-502. It behaves as a single-component refrigerant with zero temperature glide.
R-507A has a GWP of 3985 and faces the same phase-down timeline as R-404A. Systems transitioning to lower-GWP alternatives will continue to require POE oil.
| Compressor Type | Application | Recommended POE Viscosity | Qishanr Product |
|---|---|---|---|
| Small Reciprocating | Residential AC, small display cases | ISO VG32 | QSL-32H |
| Medium Reciprocating / Scroll | Commercial AC, medium refrigeration | ISO VG46 | QSL-46H |
| Large Scroll / Screw | Rooftop units, chillers, cold storage | ISO VG68 | QSL-68H |
| Large Screw / Centrifugal | Industrial chillers, process cooling | ISO VG100 – VG220 | QSL-100H / QSL-170H / QSL-220H |
Always verify the viscosity grade against the compressor manufacturer's specification. Using a viscosity grade that is too low reduces bearing film thickness and accelerates wear. Using a viscosity grade that is too high impairs oil return from the evaporator and increases energy consumption.
Converting an R-22 (HCFC) system to an HFC refrigerant (R-407C, R-410A) requires a complete lubricant change from mineral oil to POE oil. This is not optional — mineral oil is immiscible with HFC refrigerants and will cause system failure.
For detailed guidance on choosing between POE and mineral oil for your specific system, refer to our comprehensive comparison: POE Oil vs Mineral Oil: Which Refrigeration Lubricant Should You Choose?
R-134a requires polyol ester (POE) oil. POE oil is the only lubricant type that is fully miscible with R-134a across the entire operating temperature range. Mineral oil and alkylbenzene oil are not compatible with R-134a. The recommended viscosity grades for R-134a systems are ISO VG32 for reciprocating compressors and ISO VG68 for screw and centrifugal compressors.
No. Mineral oil cannot be used with any HFC refrigerant including R-134a, R-404A, R-407C, R-410A, and R-507A. HFC molecules are polar while mineral oil molecules are non-polar, making them immiscible. Using mineral oil in an HFC system causes oil to accumulate in the evaporator (oil logging), starving the compressor of lubrication and leading to bearing failure.
Using mineral oil or alkylbenzene oil with an HFC refrigerant causes three progressive failures: (1) oil separates from the refrigerant and accumulates in the evaporator, reducing heat transfer capacity by 10-30%; (2) the compressor is starved of lubrication, causing elevated bearing temperatures and accelerated wear; (3) within weeks to months, the compressor fails due to bearing seizure or excessive wear. The system must be flushed and recharged with POE oil to correct the problem.
Yes. POE oil is compatible with all HFC refrigerants including R-134a, R-404A, R-407C, R-410A, R-507A, R-32, R-125, and R-143a. POE oil is also compatible with HFO refrigerants (R-1234yf, R-1234ze) and HFC/HFO blends (R-448A, R-449A, R-452A, R-513A). This universal HFC/HFO compatibility makes POE oil the standard lubricant for n refrigeration and air conditioning systems.
R-410A residential split systems typically require ISO VG32 POE oil. Commercial R-410A systems with scroll or screw compressors typically require ISO VG46 POE oil. R-410A operates at higher pressures than other HFC refrigerants (approximately 60% higher than R-22), so the oil must maintain adequate film strength at elevated pressures. Always verify the viscosity requirement against the compressor nameplate or manufacturer documentation.
Yes. Retrofitting from R-22 to R-407C requires a complete oil change from mineral oil to POE oil. The system must be flushed multiple times to reduce residual mineral oil below 5% of total oil volume. A single drain-and-refill is insufficient — typically three flush cycles are needed. The filter drier must also be replaced with a molecular sieve type compatible with POE oil. Failure to change the oil will result in poor oil return and compressor failure.
Qishanr QSL series POE oils are formulated for full compatibility with all HFC refrigerants. Every QSL product is tested for miscibility with R-134a, R-404A, R-407C, R-410A, and R-507A across the full operating temperature range from -40°C to +120°C.
All QSL series oils are approved for use in compressors from BITZER, Carrier, Trane, HANBELL, Hitachi, York, Copeland, and Danfoss. Available in 1L, 4L, 5L, 18.9L, 20L, and 200L packaging.
Contact Qishanr for technical support, compatibility verification, and bulk pricing.
