How Do Oil-Free Air Compressors Work?


Compressed air is only as good as its purity. When your process is exposed to oil, it becomes increasingly difficult to keep air clean, increasing the costs you'll face - especially as you use more and more air. To address this concern, many companies are turning to oil-free or oil-less air compressors. Today, oil-free compressors are becoming more common because they offer cost savings.

Oil-free air compressors either have no mechanical contact inside the compression chamber or use alternate materials to protect the mechanism without lubrication.

Most oil-free compressors utilize other materials like water or a Teflon coating to keep the mechanism running smoothly. Because the lubrication of bearings and gears is all external to the compression chamber, proper sealing prevents any oil from contaminating the compressed air. The result is a 100% oil-free air supply. Some oil-free designs have even removed metal-to-metal contact within the compression chamber, eliminating the need for oil-based and synthetic lubrication altogether.

These purity and environmental benefits will often translate into other savings that may reduce your overall ownership costs. Here are a few things to consider if you're contemplating switching to an oil-free model:

  1. There's no need to collect or dispose of oil-ladened condensate;
  2. Downstream filters have reduced replacement needs, because they're not filtering oil;
  3. Energy costs are minimized because there's no need to increase force - some fluid-flooded units can see a downstream pressure drop due to filtration;
  4. Reduced oil costs, because there's no need to continually refill your compressor;
  5. Typically, these units can unload within two seconds of the unload command and will use about 18% of their full load horsepower when unloaded.

Those savings can be very tempting. To see if you can make use of the oil-less compressors, you'll need an understanding of how the compressors work, how they compare to other types of models and in which applications they work best.