Oil-Free vs. Contact-Cooled Air Compressors


Plant engineers have a decision to make in choosing an air compressor system for your facility- Oil-Free vs. Contact Cooled. The basis for that decision is actually simple- what air quality does your application call for?

Let’s look at both options, and decide from there.

Oil-Free just means the compression area will have zero oil injected for cooling and sealing to produce compressed air. These compressors use a special coating on the screws to seal, and protect the compression element.

These compressors produce the best air quality and require less clean-up (think: filtration) downstream.  However, Oil-Free comes with a higher initial investment compared to the Contact Cooled units- and frankly, most facilities do not require the air quality Oil-Free compressors are capable of. The pharmaceutical industry, food and beverage, and Health and Beauty businesses are most likely to require clean air.

Simply put, Contact Cooled just means the compression area has oil injected into the screws to seal and cool the unit. These compressors comprise over 90% of the rotary screws in service because they’re reliable, and cost much less than their Oil-Free counterparts. If your application needs cleaner air, additional filtration is required. You can achieve instrument-quality air with a Contact Cooled compressor with a robust filtration system in place.

Another advantage of Contact Cooled over Oil-Free is the time the units can spend operating before they need to be overhauled.  A Contact Cooled compressor should last 100,000 hours or more before a rebuild; where an Oil-Free unit may require an overhaul at 40,000 hours.

Take note, though- if your plant requires a higher horsepower compressor, you’ll require a Centrifugal Compressor and those are all Oil-Free.  So be aware of your air needs up front and that will prevent you from wasting time considering factors that just don’t apply to you.

As always- contact us with any questions you might have. We can guide you through the decision between Oil-Free vs. Contact Cooled.

About Michael McCulloh

Michael McCulloh

Michael McCulloh has been in the air compressor industry for 17 years and in the Industrial Market for over 20 years. He has worked with the Compressed Air Auditing Group and several compressed air Manufacturers Distribution Channels before coming to Air Components. Michael consults with clients to educate them on the best practices for compressed air systems, helps design new and existing systems to improve efficiency and reliability, and manages facilities aftermarket needs. If you have more questions or would like to work with Michael, you can reach him at MichaelMcCulloh@Air-Components.com.