Reducing Compressed Air Energy Waste:
The Immediate Steps

Every plant could save a minimum of 20% of their current compressor energy
by implementing these recommendations and conducting
a proper energy audit!

• Carefully examine hoses and fittings, valves, piping, tubing, and connectors. Defects in these components are usually prime causes of compressed air leakage. There are several techniques for finding the leaks, ranging from simply walking the air lines and listening for them, to using specialized equipment, such as ultrasonic leak detectors. Finding leaks with soap bubbles or by feel works, but is very time consuming. Ultrasonics is a much faster and more efficient methodology.

• Be mindful of wasteful misapplications of compressed air. It should not be used for blowing, drying, chip removal, or parts cleaning. Consider other alternatives that work just as well or better and cost far less to operate. Blowers, amplifiers, and other alternatives can supply the required volume of air at a lower pressure, saving significant energy costs.

• Install zero-loss moisture drains in place of timer drains. The latter blow air at regular intervals; cracked drain legs, which remain open continuously.

• Make it a policy to reduce air pressure to the actual PSI required for the job. Many companies use 110 PSI, when 90 PSI or less is more than enough. As a rule of thumb, for positive displacement compressors, every 2 PSI rise in the set point requires 1% more energy consumption. A system that could operate at 80 PSI requires an additional 10 percent more energy usage if the compressors are set at 100 PSI. That could prove to be quite costly.

• Excessive pressure is typically an indication of other plant problems. High leak rates, improper receiver sizing or placement, improper piping design, or inadequate control of the compressors are all potential causes of compressed air waste.

• Consider heat recovery from compressors. About 75% of the input energy to an air compressor is converted directly into heat. Most of this readily available heat is recoverable -- usable for space heating, air drying, and heat for various manufacturing processes such as heating boiler feed water. This is ‘zero-cost energy’ that can be readily recovered and put to use in a plant. Equipment required for this purpose is relatively inexpensive.

• Fight air system waste by educating plant personnel. Operators, maintenance technicians -- even management -- have no idea just how much an air system costs to operate. They must be informed that compressed air is not free! It must be compressed, filtered, dried, and distributed. All of these steps require costly energy.

• Include shop floor training to produce wiser decisions. Everyone from equipment operators to management to maintenance staff should be an active part of a leak detection program.

• Energy audits should be conducted by independent third parties. Some compressor and equipment vendors may have a primary goal of selling new equipment instead of optimizing what is already in place. Most plants would lower energy costs greatly if they’d just turn unused compressors off, instead of buying new ones.