The type of POE oil for R410A depends on the compressor type used in the air conditioning system, the manufacturer, and other considerations.
In general, manufacturers typically use the following types of oil, though it’s always recommended to consult the manufacturer’s specifications:
| Oil Type | Compressor Type |
|---|---|
| POE 32 cst | Piston Compressor |
| POE 32 cst | Scroll Compressor |
| POE 53 cst | |
| POE 68 cst | Rotary Compressor |
POE Oil for R410A Refrigerant
Most R410A applications are for air conditioning systems. Polyolester (POE) oil is highly hygroscopic, meaning it quickly absorbs moisture from the environment. This absorbed moisture is responsible for oil degradation.
For example, if you leave a container of POE oil open, it will absorb significant moisture from the ambient air within just 12 minutes. Therefore, it is highly recommended to keep oil containers sealed when not in use or to use an oil pump to minimize exposure.
POE Oil for a 12,000 BTU R410A Compressor
Firstly, it’s important to note that most air conditioning units with a cooling capacity of 12,000 BTU/hour typically use rotary compressors. The characteristics of the lubricant used will depend on the compressor manufacturer.
However, in many cases, the technical specifications of the compressor are unknown. As specialized technicians, we may need to replace the oil in the compressor. In such situations, the replacement oil should have similar technical characteristics to the original and come from a reputable brand to ensure a successful operation.
POE 68 oil is a common choice due to its viscosity of approximately 68 centistokes at 40°C, which ensures optimal performance at the operating temperatures of the refrigerant.
Challenges in Oil Return in Split-Type Air Conditioning Systems
Oil return can be a challenge in split-type air conditioning systems. The oil must travel from the evaporator located in the indoor unit to the compressor in the outdoor unit. During this process, certain issues, such as improper piping slope or installation, can impede the proper return of the lubricating oil.
When the oil does not return adequately to the compressor, it can result in insufficient lubrication, leading to premature wear and reduced compressor lifespan. Additionally, excess oil in the evaporator can affect system performance and lower its efficiency.
Key Characteristics of POE 68 Oil
POE 68 oil is an excellent choice for rotary compressors, not only due to its viscosity but also because of its stability. The oil used must have a viscosity index (VI) close to or greater than 100.
The viscosity index measures how much the viscosity of a lubricant changes with temperature fluctuations. Oils with a viscosity index of 100 or higher are considered stable over a wide temperature range. Conversely, oils with a lower viscosity index tend to experience more significant viscosity changes as temperatures vary.
By using high-quality POE 68 oil with a stable viscosity index, technicians can help ensure the proper functioning and longevity of air conditioning systems operating with R410A refrigerant.
