A hidden cost that most businesses do not recognize is their compressed air system.  For example, a company has a 75 HP (56KW) air compressor.  They operate two shifts for five days per week.  With an electric cost of $0.10/KWh, the annual electrical cost is around $26,000.   Because of the large amount of energy required to run an air compressor, the pneumatic system is considered the fourth utility.  And saving this commodity and using it as efficiently as you can, should be a priority.  EXAIR has many products to save this energy safely, efficiently and effectively for blow-off and many other applications. 

A recent example; I received an email from an engineer that was looking at our Super Air Nozzles.  They are currently using four blow-off lines that were made from 6mm OD copper tubes.  (Reference picture below). The system was designed to blow out holes after machining.  The engineer was in charge of the task of optimizing 25 machining stations.  He purchased four Nano Super Air Nozzles, model 1110SS, for a trial.  He was impressed with the performance, the low sound level, and the safety design.  But, for upper management, he had to show cost savings in order to change all the stations in the facility.  He asked me to help him with calculating the compressed air savings. 

He gave me some additional details about their application.  He was using the compressed air about 30% of the time throughout two shifts at 8 hours/day at a pressure of 80 PISG (5.5 bar).  He asked to know the savings per day, week, and year, as well as the payback period.  I did many of these calculations for other customers, and I was happy to help.  It is sometimes easier to speak in terms of money for everyone to relate to a situation, especially management.  (The numbers below can be adjusted to match your application and blow-off devices.)

Known:

Cost of compressed air: $0.25/1000 cubic feet of air (this is based on $0.10/Kwhr of electrical cost)

Flow: 1110SS Nano Super Air Nozzle – 8.3 SCFM at 80 PSIG

            6mm OD copper tube – 19.8 SCFM at 80 PSIG

The difference in compressed air flows from a 6mm tube to the Nano Super Air Nozzle is 19.8 SCFM – 8.3 SCFM = 11.5 SCFM.  At a 30% duty cycle, we will get 11.5 SCFM * 0.3 = 3.45 SCFM (cubic feet per minute) of additional compressed air being used.

Per day, the additional amount of compressed air wasted is:

3.45 cubic feet/minute * 60 min/hr * 2 shifts * 8 hr/day (one shift) = 3,312 cubic feet per day.

Per week, the additional amount of compressed air wasted is:

3,312 cubic feet/day * 5 days/week = 16,560 cubic feet per week.

Per year, the additional amount of compressed air wasted is:

4,896 cubic feet/day * 250 days/year = 828,000 cubic feet per year.

With the cost to make compressed air at $0.25/1000 cubic feet, we have the following:

3,312 cubic feet/day * $0.25/1000 cubic feet = $0.83 per day

16,560 cubic feet/week * $0.25/1000 cubic feet = $4.14 per week

828,000 cubic feet/year * $0.25/1000 cubic feet = $207.00 per year.

From these values, the payback for a single, model 1110SS Super Air Nozzle is just under 76 days. 

The remaining life of the Super Air Nozzles will save the company a lot of money by using less compressed air.  The calculations above are only for one nozzle.  As discussed above with the engineer, they had 4 tubes/ station and 25 stations in their plant.  So, if you multiply the yearly figure at $207.00 * 100 = $20,700.00 per year.  The engineer presented these figures to upper management, and it was an easy decision to replace each copper tube with an EXAIR model 1110SS nozzle.  

Don’t be fooled by the upfront cost of tubes or pipes with drilled holes, or other substandard or “homemade” nozzles.  You can see by the facts above that if you use any additional compressed air in your blow-off application beyond that which is necessary, it will cost you in the long run.  If you need help in doing calculations for your applications, EXAIR does have an Air Savings Calculator on our website, or you can contact an Application Engineer directly.  It is like changing your incandescent light bulbs to LED light bulbs for energy savings.  It just makes good business sense. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: Energy saving lamp by Alexas_Fotos.  Pixabay Content License