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Clean Air Supply – Refrigeration, Dryer, Filtration

17 November 2021

When you’re working with compressed air, it’s vital to have a clean air supply, free from solid particles, water, oil and, in certain cases, odours/vapours. There are a few good reasons for this. Firstly, so that your equipment can operate at maximum efficiency. Secondly, to reduce excess wear and the possibility of rust. Thirdly, following on from the second point, to lessen parts of the system getting stuck/breaking down and requiring maintenance. And lastly, in the case of the odours/vapours, because the system is being used for the production of food or medicine.

So how can you ensure your air supply is clean? As we’ll explain below, three of the key areas on which to focus are refrigeration, dryer and filtration.


Air coming out of an air compressor is basically too hot to be useable in compressed-air equipment and so must be cooled by an aftercooler. These devices not only remove the heat from the air, but also remove most of the moisture and solids. This reduces the possibility of rust and other build-up, while also preventing mechanical issues. Aftercoolers themselves can be air- or water-cooled.


A common type of dryer used with compressed-air systems is the refrigerated compressed air dryer. It cools the air in the same manner as a household fridge, producing liquid water which can then be drained away.

Another sort of dryer is the dessicant compressed air dryer. It removes water from the air using an alternative method – tanks of a special material known as a dessicant to which the unwanted water adheres.


As you might expect, filters protect compressed-air equipment from solid particles, water, oil and odours/vapours. There are various filter options available.

Like the name suggests, particulate filters remove particles from the air supply. Because this dirt and dust is captured by the filter, over time it will fill up and reduce in efficiency, eventually needing to be cleaned or replaced.

Rather than trapping particles like particulate filters do, coalescing filters cause water and oil molecules to clump together and then drop to the bottom of the filter where they are drained away. These filters also require cleaning or replacing over time.

A special type of filter usually associated with the production of foodstuffs or medicines, activated-carbon filters occur later in the system than the preceding filters. After the air has already been cleansed of solid particles, water and oil, an activated-carbon filter can remove any unwanted odours/vapours. Think of this as the difference between clean air suitable for machines and purified air suitable for human consumption. Again, these filters must be monitored and cleaned/replaced when necessary.

It’s About More Than Just Clean Air!

While the refrigeration, drying and filtration equipment above all has an initial cost, investing in good-quality models suited to your compressed-air system will save you money in the long run on repairs, replacements and company downtime. It will also spare you a lot of hassle.

Air Supply Not Up to Scratch?

We can help! For expert advice on all of your compressed-air and pneumatic-system needs in the south-east Queensland region, don’t hesitate to contact Cospaker Pneumatics. You can find the phone numbers for our Gold Coast, Brisbane, Beenleigh and Tweed Heads offices on our website here.

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