Oil-Injected Air Compressors

An oil-injected compressor uses oil in the compression chamber to lubricate, seal, and cool the air during compression. This design improves your energy efficiency, reduces wear, and supports consistent performance, making oil-injected air compressors ideal for continuous use in general manufacturing, workshops, and more.

An oil-free air compressor produces 100% oil-free air, eliminating any risk of oil contamination in your compressed air. In contrast, an oil-injected air compressor uses oil for lubrication, which may carry over into your compressed air system. The right choice depends on your air quality requirements and specific application requirements.

Oil-injected compressors are widely used in general manufacturing, automotive, construction, and heavy-duty compressed air applications. Understanding specific application requirements is crucial when choosing between oil-free and oil-injected compressors. They’re ideal where air quality is important but not critical and where efficiency, reliability, and lower cost of ownership matter most to your operation.

Oil-injected screw compressors use internal oil filters, oil coolers, and oil separators to minimise oil contamination in your compressed air. With regular maintenance, you can ensure optimal air quality and protect your downstream equipment.

The size of the compressor you need is completely dependent on the air-operated equipment you plan on using. To work out what size would be best for you, add up the air usage of all air tools that will be used simultaneously. It’s best to add an extra 20-25% to allow for future usage down the track. This is only a rough guide, the best way to ensure you have the correct size machine is to get a compressed air energy audit.

No, they don’t. You should always check for any problems after the first start-up. However, once that’s done, you’re good to go. If you notice any leaks or issues, turn off your compressor and contact your product provider before operating any air compressor equipment again.

Choosing between an oil-free and oil-injected compressor depends on your air quality needs, budget, and, of course, application.

If you need a completely oil-free environment, such as in food production, pharmaceuticals, or medical procedures, an oil-free compressor is the only suitable option. These systems prevent oil carryover that could contaminate products or processes.

Oil-Injected Air Compressors

• Most common screw compressor type in Australia
• Often, the most cost-effective option, depending on your requirements
• Durable/reliable for continuous use even in hot environments
• Will require regular oil changes and filter servicing
• Not suitable for oil-sensitive applications

Oil-Free Air Compressor

• Essential where oil-free air is critical (e.g. medical, food, cleanroom, electronics)
• Typically has a higher purchase cost
• May require specialist compressor servicing
• Scroll models are known for quiet operation and low vibration
• Suitable for intermittent or sensitive-use industries

While oil-free air compressors provide clean, contamination-free air, there are a few trade-offs to consider. They are typically more expensive to purchase and may have a shorter lifespan in high-demand or continuous-use environments. Some models may require more frequent filter changes or specialist servicing to maintain performance.

In contrast, oil-injected compressors use oil to cool and lubricate internal components, which can improve energy efficiency and extend the life of the machine. However, they require more maintenance and are not suitable for applications that demand completely oil-free air.

The energy efficiency of your air compressor depends not only on the unit itself but also on how your entire compressed air network is designed and maintained. A well-designed air piping system plays a crucial role in reducing pressure drops, minimising leaks, and maintaining consistent air temperature and flow.

Oil-injected rotary screw compressors are often among the most efficient options, especially when paired with an optimised air piping system. For the best results, have your compressed air system audited to assess how your compressed air is distributed and used. Improving layout, materials, and pipe diameter can lead to significant energy savings and enhanced system performance.

Many air compressors are able to run off generators however, it is not recommended. If you have access to mains electricity, it is recommended that you use that to power your air compressor equipment. Generators have fluctuations in power, which can cause problems for compressors as they require a constant voltage to run. It is even more important for rotary screw compressors to be run off mains electricity rather than generators due to their constant operation and the need for a stable power supply for the motor.

The frequency of oil change depends on your air compressor model, how you use it and the age of the machine. The best way to ensure it is being changed adequately is to have your oil-injected air compressor serviced regularly by a professional air compressor servicing business.

The timing of your air compressor maintenance or servicing will depend on your model of oil-injected air compressor, as well as your specific system setup and usage. Regardless of the exact intervals, regular servicing is crucial for maintaining the reliability of your oil-injected compressor.

You should have the oil filters, oil separator, and thermostatic valve checked regularly and have the oil changed based on usage and model. Always follow your manufacturer’s recommendations or speak with a specialist to create an air-compressor servicing schedule that suits your needs.

If you’re worried that your air compressor isn’t working as it should, turn it off immediately and have a qualified air compressor technician inspect it before continuing use.