What Type Of Oil Does R 404a Use

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As an HVAC technician, I’ve come across various refrigerants throughout my career. One commonly used refrigerant is R-404A. In this article, I’ll delve into the type of oil that R-404A uses and provide you with some insightful information on this topic.

R-404A is a blend of three hydrofluorocarbons (HFCs) – R-125, R-143a, and R-134a. Each component plays a crucial role in its overall performance and characteristics. When it comes to the type of oil used with R-404A, it’s important to note that it requires a polyolester (POE) oil.

POE oil is a synthetic lubricant specifically designed for use with HFC refrigerants like R-404A. It has excellent compatibility with these refrigerants and provides optimal lubrication for the compressor. POE oil also has good thermal stability and high viscosity index, ensuring smooth operation and extended compressor life.

When working with R-404A, it’s essential to choose the right POE oil viscosity. The oil viscosity depends on the compressor type and its operating conditions. Typically, a viscosity range of ISO VG 32 to ISO VG 68 is suitable for R-404A systems.

Using the correct oil viscosity ensures proper lubrication, prevents oil breakdown, and reduces the risk of compressor failure. It’s crucial to follow the manufacturer’s guidelines and specifications when selecting and adding oil to an R-404A system.

When it comes to handling and adding oil to an R-404A system, it’s best to rely on a professional technician. They have the expertise and knowledge to determine the appropriate oil type and quantity needed for the specific system.

Overall, R-404A, a popular refrigerant used in commercial refrigeration and air conditioning systems, requires a polyolester (POE) oil for optimal performance. The use of the correct oil viscosity and following manufacturer guidelines is crucial to ensure proper lubrication and prevent compressor failure. If you’re unsure about the oil requirements for your R-404A system, it’s always wise to consult with a qualified HVAC technician.


Understanding the type of oil that R-404A refrigerant requires is essential for maintaining the optimal performance and longevity of your system. By using a polyolester (POE) oil with the appropriate viscosity, you can ensure proper lubrication and prevent potential issues. Remember, when it comes to oil selection and handling, it’s always best to consult with a professional to guarantee the best results for your R-404A system.