Air Compressor Works
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Did you know that most air filters in compressed air systems should be changed from time to time, about every six to twelve months? Keeping these elements changed is very important to the quality of your compressed air. If you don’t change them in a timely manner, then you might as well not have them at all – all of the junk you were trying to keep from getting in your equipment will get through!

Occasionally, we have customers that will hold off ordering elements for as long as they can in the hopes that everything will still continue working as normal, even if the differential pressure gauge on the filter is showing it’s time to change. While elements can be expensive, it’s always cheaper to stay on top of things than to suffer from downtime and costly repairs. 

Many systems have a differential pressure gauge, which measures the pressure before the filter and the pressure after the filter, ultimately showing you the pressure drop across the filter. This is another helpful way to determine if your filter needs changing.

Examining Pressure Drop

Pressure drop in your compressed air system is bad. Every filter has a pressure drop – it’s inherent to all filters. A clogged filter, however, will often be 10 psi or more above and beyond your normal filter pressure drop. Keep in mind, every 2 psi increase in pressure is about a 1% increase in energy use. That means the compressor or compressors upstream will be using 5% more energy.   

Let’s look at an example, an average installation in the USA with the following metrics:

• 30hp air compressor running about 60 hours per week
• The motor has a 1.1 service factor, 91% efficiency, and the electrical cost is 12¢ per kWh

Not changing a clogged filter costs about $10/week, $40/month, and $520/year. The filter element in question costs between $150-$200 brand new, or half that for an aftermarket. Here, you can see that holding off another two months changing the filter will cost them about $80 on the electrical bill. 

If you have a large manufacturing plant, you probably have between 100-300hp worth of air compressors and you likely run 80 hours per week.  Not changing the filter costs about $43/week or $170/month for every 100hp (using the same metrics as above).

These numbers are just for one filter. It is typical to see two or three filters in the line, and if you have a desiccant dryer, there are usually two filters before and two filters after.  A big plant with 300hp worth of compressors would use an extra $2,000 per month in electricity by not changing them!

You can’t afford not to change them.

Holding off hold off on filter maintenance will:

1. Contaminate your process.
2. Run up your electrical bill.
3. Force your compressor to work harder, which can put unnecessary strain on it in the long run.

As you can see, it doesn’t make sense to not change your air filters when it’s time.

Learn more about our Preventative Maintenance services and programs for your system, as well as our Rental options.