If you’re new to the air compressor purchasing process, one of the biggest distinctions you’ll come across in the industry is oil vs. oil-free air compressors. For any company, an air compressor is a big investment — and a necessary one. In most manufacturing facilities, if your air compressors are down, you’re not working.

Purchasing the right air compressor is a big decision and one that can require a bit of research. In this article, we’re going to break down the differences between the two and help you decide which option is right for your application.

Oil vs. Oil-Free Air Compressors: What’s the Difference?

The difference between oil and oil-free air compressors is the lubrication method used to keep an air compressor’s air-end moving smoothly. Most industrial air compressors use oil-injected compressors because they are less expensive and tend to last longer than their oil-free counterparts. An oil-free air compressor is just what it sounds like — an air compressor that does not use oil to lubricate components in the compression chamber. Although they require a larger monetary commitment, an oil-free air compressor may offer your facility priceless benefits.

Why Would You Use an Oil-Free Air Compressor?

If they’re more expensive to purchase and maintain, why would a manufacturing facility choose an oil-free air compressor over an oil-lubricated air compressor? It has to do with the air compressor’s application.

An oil-injected compressor is very effective at delivering compressed air quickly and consistently. The oil lubrication can help extend the life of the compressor, but the drawback is that during the compression process, oil particles or oil mist can get into the air that’s being compressed. This can lead to oil contamination in the compressed air you’re getting out of your system.

For many parts manufacturing workshops and industrial applications, a bit of oil contamination isn’t a problem. For sensitive applications, however, oil contamination is unacceptable. In these situations, an oil-free air compressor is necessary. Since these air compressors don’t use oil in the compression chamber at all, they can deliver a cleaner, oil-contaminant free compressed air end-product.

What Applications Can Benefit from an Oil-Free Air Compressor?

Since most applications do use an oil-lubricated air compressor, it’s easier to define the industries that do not. The following industries require a certain standard of air purity that means an oil-free air compressor is necessary:

• • Pharmaceutical applications
  • Food and beverage manufacturing
  • Electronics
  • High-tech manufacturing
  • Textile manufacturing
  • Robotics development
  • Paint applications
  • Some automotive manufacturing applications

The easy answer to the oil vs oil-free air compressor question is this: if air quality matters to you, you need an oil-free air compressor.

Understanding Air Purity Requirements for Oil vs. Oil-Free Air Compressors

If you’re not quite sure if air quality is important enough to your application to warrant an oil-free air compressor, check your ISO Class requirements. Compressed air has its own set of ISO standards, ranking air purity from ISO Class 0-5. If your application requires an air purity standard of either Class 1 or Class 0, you’ll need an oil-free air compressor. These two standards are often misunderstood, so we’ll break them down a bit further.

ISO Class 1 – Mostly Oil-Free Air

Compressors that meet a Class 1 ISO are considered to produce “mostly clean air”. That’s to say, an air compressor that provides air that meets Class 1 ISO standards must have an oil concentration of 0/01 mg/m3 at 1 bar(a) 14.5psia and 20° C (68°  F). It’s important to know that this standard doesn’t mean the resulting compressed air is totally oil-free.

ISO Class 0 – Oil-Free Air

If you’re looking for totally oil-free air, choose an oil-free air compressor that delivers air according to ISO Class 0 standards. These compressors can guarantee 100 percent oil-free air, a claim that ISO Class 1 compressors cannot make. With an ISO Class 0 compressor, you can be absolutely certain that no contamination will reach your resulting product or end consumer.

In Conclusion: Oil vs. Oil-Free Air Compressors

Choosing an oil vs oil-free air compressor comes down to your application. If you need clean, oil-free air, an oil-free air compressor is right for you. If the air quality doesn’t matter as much for your application, an oil-lubricated air compressor is a durable, high-performance option that will deliver the air you need at a more affordable investment level.

Whether an oil or oil-free air compressor is right for your application, TMI has the brand and model you’re looking for. As air compressor experts, we can design the system that’s best for your facility, and install and service your new air compressor. With reasonable rates and convenient maintenance programs, never worry about your air compressor again. Give our team a call at 800-875-955 or contact us online today for a personalized quote.

Contact TMI Air Compressors