The choice between lubricated and oil-free air compressors impacts various industries and applications. Despite both types of compressors serving the same purpose — generating compressed air — they have fundamental differences in their operation and maintenance requirements.
When you understand the differences between oil-free and oil-lubricated air compressors, you can make an informed decision to ensure your compressed air system aligns with your operational needs and environmental objectives.
Also known as oil-flooded or oil-lubricated air compressors, lubricated compressors use oil as a lubricant and coolant in the compression chamber. This air compressor finds use in the automotive, construction and manufacturing industries, among others. Key features include:
- Lubrication and wear reduction: The oil in this compressor serves multiple purposes aside from lubrication. It reduces wear and tear, seals the compression chamber and cools the compressed air or gas. Often, you will see a separate oil circulation system and reservoir that maintains the lubrication aspect.
- Positive displacement: Lubricated compressors work on the principle of positive displacement. Using a piston or rotary mechanism, they draw in air or gas and compress it by reducing the compression volume in the chamber. Oil in the compression chamber reduces friction, dissipates heat and seals gaps to create efficient compression.
- Performance stability: This type of air compressor is very efficient and reliable, offering consistency in its performance. It also provides higher compression ratios and features a longer operational life span with proper maintenance.
Help your oil-flooded air compressor operate for longer by keeping up with the maintenance of its various components. Periodically check the following:
- OEM-approved oil: Oil approved by the original equipment manufacturer (OEM) is the best choice to support the integrity and functionality of your air compressor.
- Airend inspection: Overheating, condensation, poor lubrication and corrosion can damage the airend, resulting in a breakdown. By inspecting this component regularly, you can avoid downtime.
- Oil and air leaks: Leaks decrease operational efficiency, and you can detect them using ultrasonic leak detection technology.
- Check the hoses: Cracks and corrosion can result in leaks that reduce the energy efficiency of your air compressor.
- Drain condensation: Draining the receiver tank on a regular basis keeps it clean, helping to ensure that it operates effortlessly.
Oil-free, or oil-less, air compressors use pre-lubricated materials like water or Teflon to coat cylinders, with some of these compressors using water to cool and lubricate. Like lubricated air compressors, oil-free compressors work by using rotors with tight mechanical tolerances that reduce component friction. The difference is that oil-free compressors deliver clean, contaminant-free compressed air. Other key characteristics of these air compressors include:
- Reduced environmental impact: Since these air compressors do not use oil, there is no risk of oil spills or leaks.
- Lower initial cost: Oil-free compressors offer lower initial costs and additional savings over time because they require less scheduled maintenance.
- Compact design: You can find these air compressors in compact designs to use in workspaces with limited space.
- Compliance factors: As they produce clean air, oil-free compressors often comply with industry certifications and standards relating to air quality.
Oil-less compressors are less demanding when it comes to maintenance. However, as with any piece of machinery, you need to conduct routine inspections to keep it functioning for longer. Part of this is checking for any leaks, damage or signs of wear:
- Change the air filters: Replace the air filters regularly to prevent air intake contamination, ensuring that the air quality remains optimal.
- Monitor lubrication: Although this air compressor does not use oil, some models have a small oil system to cool the machine. Check these oil levels periodically to ensure they stay in the recommended range.
- Vibration analysis: Perform a vibration analysis occasionally to identify abnormal vibrations and misalignments in the compressor components.
- Condensate drain: Drain the condensate regularly from the air receiver or tank to prevent moisture buildup. Be sure to dispose of the drainage properly, according to environmental regulations.
Choosing Between the Two
Choosing the suitable compressor depends on the primary application you plan to use it for and the air quality your application requires. The differences between oil-free vs. lubricated air compressors extend beyond the presence of oil. Lubricated air compressors are often put to use in construction and heavy-duty industrial applications. The portability of oil-free compressors and their air quality make this a popular choice in health care.
Lubricated compressors come with a longer life expectancy. Because they use oil, components experience less friction, so there is less wear and tear. This durability makes these compressors well-suited for commercial applications where they will run continuously.
As oil-free compressors do not feature an additional chamber for oil reserves, they are often smaller than lubricated compressors. Their size means they are more portable, making them a good choice for worksites. Lubricant air compressors are more challenging to move around, making them better suited for applications where they can stay in one spot.
Noise levels can disrupt certain operations, making this a primary consideration in the choice of air compressor. If you are looking for a quiet device, lubricated air compressors are the optimal choice, as their oil use allows them to produce less sound. You can also make a decision between oil-free and lubricant air compressors based on safe noise levels in various workspaces.
Lubricated and oil-free air compressors have different impacts on the environment. Oil exposure makes it difficult to keep the air clean. If your industry falls in the food processing, pharmaceutical or electronics sectors or has strict air quality guidelines, oil-free compressors are the right choice. Lubricated air compressors can suffer oil contamination, whereas oil-free compressors provide air that contains no oil vapor or particulates.
Lubricated compressors require more maintenance, which includes oil changes, to ensure the machine offers optimal performance. Maintenance alone should not be your deciding factor, though. While oil-free compressors need less scheduled maintenance, they have a shorter life span.
Lubricated and Oil-Free Air Compressors From Quincy Compressor
As compressor technology advances, both oil-free and oil-flooded air compressors will increase in efficiency and reliability for a variety of applications. Your best bet is always to purchase compressors from a reliable provider.
With a legacy built over 100 years, Quincy Compressor delivers high-quality air compressors to suit your specific industry needs. We manufacture various products to the highest standards to ensure your air compressor performs well for as long as possible. Shop our compressor products online, or contact us today and an industry expert will reach out to help you find the product that best suits your application.