Push-Button Compressed Air Savings

By Ron Marshall, CET, CEM for the Compressed Air Challenge (CAC)

When it comes to compressed-air systems, you can sometimes achieve real savings by simply pushing a button or flicking a switch. Photo: FS-Elliott

The best way to gain savings from your compressed air system is to conduct a careful analysis of the complete system and address all areas of concern. But sometimes real savings can be gained by simply pushing a button or flicking a switch.

You may not be aware you have such power at your fingertips, but it is true. Air compressors and auxiliary equipment such as air dryers have very little ability to make decisions concerning energy consumption; it is most often up to you to tell your equipment what to do.

For example, your air compressor will run all day to supply your plant with the needed air pressure for your production equipment. It will also continue to feed leaks all night, all weekend, and on holidays if left on its own. By providing feedback to the system, i.e., by pushing the “off” button when compressed air is not needed, you can save thousands of dollars in wasted energy and reduce your maintenance costs. If you are lucky enough to have a compressor with special scheduling functions, you can push a few buttons to enable the compressor to automatically turn itself off during non-productive times.

Perhaps you have a compressor that is barely loaded or is running unloaded all the time in case the main compressor fails. Most screw-type compressors consume 25% to 35% of full-load power in the unloaded position, wasting power while producing no air. You may be able to save additional power during production times by enabling the “auto” feature, which turns the compressor off when there’s been no demand for a set period of time. This saves unloaded power consumption, but keeps the system armed to start if pressure drops below a set target level.

Your compressors may also be operating in an inefficient control mode. Often, screw-compressor control modes will be set with a selector switch or push-button control function. One of the least efficient ways to control compressors is modulation mode. Sometimes, if your system has proper storage-receiver capacity and adequate pressure settings, flicking a selector switch to load/unload mode can save you a bundle.

Refrigerated air dryers can consume almost full power if they are non-cycling units and are left running when the air compressors are off. Pushing the off button when you put your compressors to sleep can save extra power costs. If you have desiccant dryers, be aware that, sometimes, energy-savings control modes are built into the units and can be activated with a push of a button to save thousands of dollars in energy costs.

Additional switches, levers, and dials can also be used to control auxiliary equipment to recover heat, save cooling water, reduce ventilation-fan run time, and even turn out the lights in the compressor room to save a little extra.

Exercise your fingers today and see how much money you can save!

More information about compressor efficiency can be found at the CAC website or in CAC’s Best Practices for Compressed Air Systems manual. Check the website calendar for scheduled training. MT

rcmarshall@hydro.mb.ca

The Compressed Air Challenge is a partner of the U.S. Department of Energy’s Industrial Technology programs. To learn more about its many offerings, log on to compressedairchallenge.org, or email info@compressedairchallenge.org.