Compressed air is an expensive utility for most industrial applications. The cost of generating a 1,000 Standard Cubic Feet is $0.25. A typical 25 HP screw compressor will generate 52.5 million cubic feet per year. To generate 52.5 million cubic feet will cost $13,140 in electricity costs. Running this compressor more than necessary will lead to higher maintenance costs and higher electricity costs. Also, decreasing your compressor load will delay or avoid a capital expenditure, as your plant expands and production grows. Anything you can do today to limit wasted compressed air will pay for years to come. Here are 3 ways you are currently wasting compressed air.
ONE> Open Ended Blow Offs – The benefits of eliminating open ended blow offs in your plant are numerous and drastic. Saving air by outfitting open ended blow offs with an engineered solution (EXAIR air nozzle, air knife, air amplifier) is a significant portion of compressed air conservation. It is an easy install and can save a great deal of compressed air. The situation always starts innocent enough: Five years ago Company X installed a new production line, but found that they needed a compressed air blow off to move, clean, dry or cool a part. The blow off may not have been planned in the original specification, or the engineering company that specified the line did not take into account the compressed air cost of the line. The maintenance department is under pressure from the management to get the line running, and an open pipe works to get the line running. Since the compressed air already existed in the plant, it is free, cheap, or easy … for them. But what will it cost your company?
A Super Air Nozzle will use 14 standard cubic feet per minute (SCFM) at 80 PSIG of inlet pressure. A 1/4″ inside diameter 18″ long tube will use 50.5 SCFM. Now the compressor system in your facility is working harder by 36.5 SCFM. This means your next compressor will be 10 HP larger than it needs to be to keep up with excessive demand. In addition, 36.5 SCFM running 24 hours a day is 52,560 Standard Cubic Feet, which costs $13.14 to generate. Over a year that is $3,285, because the knowledge and time to install an engineered compressed air nozzle does not always present itself. Just imagine the cost, if you have 5 open blow offs, or 50?
Open blow offs can also violate OSHA requirements for using compressed air for cleaning, when pressurized above 30 PSIG. Not to mention they generally are louder than 90 dBA, which is the maximum allowable noise exposure without hearing protection under OSHA standard 29 CFR – 1910.95 (a). A nozzle is a simple way to avoid a OSHA fine. If the money didn’t convince you to use an engineered nozzle, the cost to your employees health and hearing should.
TWO> Leaky Distribution System – Second, we come to the most simplistic way of wasting compressed air: Leaky pipes. It seems impossible that the small air leaks that occur in almost any compressed air system would amount to a large cost that would be significant in any way, but as we discuss here. It can happen to the best of us. It is estimated that over 30% of compressed air generated is lost to leaks in a compressed air system, before it is used at its intended point. Do not let this happen in your facility. Have an auditor come into your facility to check your system, or conduct your own air leak survey using our Ultrasonic Leak Detector.
THREE> Leaving Compressed Air on All the Time – Lets say that your part only crosses in front of the blow off every 15 seconds, and the part takes 5 seconds to cross in front of the that blow off. That means that there are ten seconds in every cycle where compressed air is wasted. Let’s continue our example of the 1/4″ inner diameter copper tube that is 18″ long above. How much are those 10 seconds costing you? 10 seconds times 4 cycles per minute is 40 seconds of wasted air every minute. In 40 seconds 24.3 SCFM air is wasted. 24.3 SCFM of wasted air will cost $2,187 per year with a 24 hour work day and 250 working days in a year.
Even after lowering your total consumption by installing an engineered air nozzle on your open blow off, there is more opportunity to reduce compressed air. If you have Super Air Nozzle already installed and have realized some very good air savings, you can still turn off your compressed air flow for 10 seconds every cycle in our example. In the case of the Super Air Nozzle that will be 9.33 SCFM, which will still cost $837 per year. If you are looking for an easy way to turn your air on and off only as needed during your process, the EXAIR Electronic Flow Control is a great system to further fine tune your compressed air use. To do your own calculation, EXAIR’s Air Savings calculator is a great tool for calculating the cost of compressed air.
Most of these items require some type of expenditure to complete, but paying for a nozzle, an air survey or a control system will lower your compressor load everyday you work. EXAIR’s Application Engineers are available everyday to access your compressed air systems. We would be happy to help you determine the ROI for any compressed air system upgrade. You can read about our success stories on our website at Case Studies (we do ask you to register before viewing our case study successes).
Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW
