The 5 Most Common Oil-Free Air Compressor Myths

Many misconceptions surround oil-free air compressors – and oil-free compressed air in general. Today we’re tackling 5 of these myths that are often discussed in the compressed air industry!

1. Oil-free air compressors do not use oil. While oil isn’t used in the compression chamber, meaning that oil doesn’t come into contact with the air being compressed, oil is still used to cool the compressor and lubricate the moving parts. Sealing systems are integrated into the compressor to block any oil from entering the compressed air system.
   
   
2. Compressed air produced by oil-free air compressors is contaminant-free. False! There are many contaminants in atmospheric air, including water vapor, oil vapor, microorganisms, and water aerosols. Other sources of compressed air contamination include the compressor itself, compressed air storage devices, and compressed air distribution piping. This means that compressed air produced by oil-free compressors isn’t necessarily contaminant free – though using air treatment products can assist in reducing contamination to the required level.
   
   
3. Air treatment products aren’t needed in oil-free compressors. It’s common to omit or wholly exclude downstream filtration when using an oil-free air compressor. However, these products (particulate and coalescing filters, for example) are essential to remove existing contaminants from the compressed air and to reach the purification level required by your application.
   
   
4. Oil-free air compressors have a lower cost of ownership. In actuality, oil-free compressors have a higher initial capital cost than their oil-injected counterparts. However, for sensitive applications requiring oil-free air, their cost of ownership over years of operation will be less than “technically oil-free” alternatives requiring frequent servicing of the filtration system and the higher electrical costs associated due to the filtration system pressure losses. Moreover, there is always an inherent risk of contamination with “technically oil-free” in the event of filtration system failure.
5. All oil-free air compressors produce Class 0 oil-free air. There are different levels or class of “oil-free” compressed air as set forth by the International Organization for Standardization (ISO), which establishes the global standards for compressed air purity. Class 0 is the cleanest air, and as such must meet the most stringent quality requirements and is more stringent than class 1. Using Class 0-certified compressors ensures the highest standard.  

Need help in selecting the ideal oil-free compressor, or have a question concerning one of the myths described above? Contact an Atlas Copco expert today! You can also take a look through our complete line of oil-free options here.