Compressed Air Efficiency Results in Better Business!

Time and time again we write about how compressed air is considered the fourth utility in a manufacturing setting. Compressed air is a great resource to use, however it needs to be used responsibly!

How you use it in your business is important, for a couple of key considerations:

The Cost of Compressed Air

Compressed air isn’t free.  Heck, it isn’t even cheap.  According to a Tip Sheet on the U.S. Department of Energy’s website, some companies estimate the cost of generation at $0.18 – $0.30 per 1,000 cubic feet of air.  A typical industrial air compressor will make 4-5 Standard Cubic Feet per Minute per horsepower.  Let’s be generous and assume that our 100HP compressor puts out 500 SCFM and is fully loaded 85% of the time over two shifts per day, five days a week:

500 SCFM X $0.18/1,000 SCF X 60 min/hr X 16 hr/day X 5 days/week X 52 weeks/year =

$22,464.00 estimated annual compressed air cost

So to minimize the compressed air use and the over all generation costs there are six easy steps to follow!

  1. Measure: the air consumption You must create a baseline to understand your demand requirements. How can you measure your improvements if you do not understand your total demand or baseline? Installing an EXAIR Flow Meter to your main air lines will help identify the amount of compressed air demand you have and help identify areas of concern.
  2. Find and fix leaks in the system: The repair of compressed air leaks is one of easiest ways to gain energy savings. In most cases all you need is a keen sense of hearing to locate a leak. Once a you have confirmed a leak then the make the necessary repairs. Harder to find leaks may require tools such as EXAIR’s Ultrasonic Leak Detector. This is a hand held high quality instrument that can be used to locate costly air leaks.
  3. Upgrade your blow off, cooling and drying operations: Updating your compressed air process tooling can save you energy and help you comply with OSHA noise and safety regulations. An example would be to replace old blow off or open pipe systems with EXAIR Safety Air Nozzles. Replacing open copper tubes or pipes can amount up to 80% air savings. You achieve lower sound levels and significant energy savings.
  4. Turn off the compressed air when it isn’t in use: It sounds obvious but how many times has an operator left for a break or lunch and doesn’t shut off the compressed air for his/her station? The minutes add up to a significant amount of time annually meaning there is opportunity for energy savings. The use of solenoid valves will help but EXAIR’s Electronic Flow Control (EFC) will dramatically reduce compressed air costs with the use of a photoelectric sensor and timing control.
  5. Use intermediate storage of compressed air near the point of use: The use of storage receivers can improve your overall system efficiency in a number of ways. For example, using a main air receiver at the compressor room can make load/unload compressor control more efficient. Localizing receiver tanks such as EXAIR’s 9500-60 sixty gallon receiver tank by the point of use for a high demand process will stabilize the demand fluctuations allowing a more fluid operation.
  6. Control the air pressure at the point of use to minimize air consumption: The use of pressure regulators will resolve this issue. Using regulators you can control the amount of air being processed at each point of use. EXAIR offers different sized pressure regulators depending upon your air line and process requirements. Regulating the compressed air to the minimum amount required and will reduce your overall demand resulting in annual savings and a payback schedule.

Health & Safety

Injuries and illnesses can be big expenses for business as well. Inefficient use of compressed air can be downright unsafe.  Open ended blow offs present serious hazards, if dead-ended…the pressurized (energized) flow can break the skin and cause a deadly air embolism.  Even some air nozzles that can’t be dead ended (see examples of cross-drilled nozzles on right) cause a different safety hazard, hearing loss due to noise exposure.  This is another case where EXAIR can help.  Not only are our Intelligent Compressed Air Products fully OSHA compliant in regard to dead end pressure, their efficient design also makes them much quieter than other devices.

Efficient use of compressed air can make a big difference in the workplace – not only to your financial bottom line, but to everyone’s safety, health, and livelihood.  If you’d like to find out more about how EXAIR can help, give me a call.

Jordan Shouse
Application Engineer

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Compressed Air System Equipment

Compressed air is a valuable utility and understanding what makes up a solid system is very important. Most all manufacturing facilities have a demand for compressed air, so today we’ll discuss how when managed well, and with the proper equipment, how valuable this utility can be.

The equipment begins with the compressor. Specifying which compressor is best for you is genuinely specific to your needs, and many times even your geography. How many “users” of the air, the distance the air has to travel, how many and how sharp of turns need to be made are all specific to your building and setup. Drastic temperature changes, night and day, and many times summer to winter, can effect the compressor as well. Here is a list of things to consider when purchasing or upgrading the compressor itself:

  1. What is the actual air requirement? (SCFM) – as a rule of thumb – every 1 HP = 4 SCFM
  2. How many shifts, and do these shifts vary in air consumption?
  3. Average and Maximum Flow requirements
  4. What about leaks?
  5. What about the future?
  6. What is the highest pressure needed and why?
  7. How far away form the source are the users?
  8. Would a receiver tank/intermittent storage in the loop benefit your situation?

Compressor: Once you fully have a grasp of your demand, you can now move on to the compressor. There are 5 main types of compressors. One of the most common is the single-stage lubricant injected rotary screw compressor. This compressor is also offered in 2 stage. The other 3 types are a) 2-stage double acting reciprocating compressor b) Lubricant free screw compressor and c) Centrifugal 3-stage compressor. Each of these compressors have their own unique characteristics, benefits and faults. We highly recommend getting a local Air compressor company or professional involved to ensure the correct type and size.

Dirty Inlet Filter: Once the compressor is specified, you will need to ensure you have the best solution for dirty, ambient air being pulled into the compressor. The air coming out, begins with the air coming in, so this filter needs careful consideration based upon your individual ambient conditions. We’ve all heard the saying “garbage in – garbage out”… This filter should be checked, washed or changed often.

Receiver tank: The compressor(s) feed into a receiver tank. Many times this is call the Control Receiver, or the wet tank or cooling tank. Receiver tanks take in the air from the compressor and hold it under pressure for future use. These tanks reduce the cycles on the compressor, and prevents excessive loading and unloading in the system. These are not used on every system, but should be.

Dryer: Regardless of where you are in the world, all atmospheric air has some amount of vapor which will begin to condense into water when the air is cooled to the saturation point (This saturation point is better known as the dew point). The amount of moisture in the air depends on the temperature and relative humidity. As a rule of thumb, the moisture in the air will double for every 20°F increase in temperature. Your dryer should be able to dry the air to a dew point that is at least 18°F below the lowest temperature at the use point of the air. The size and amount of dryers is completely dependent on your companies needs.

Coalescent filter: Right after the dryer, it is recommended to put this type of filter to remove any other condensate, oils, or lubricants from the compressor. Unwanted oil in in the system can effect the machines and tools being used with the air.

Once your pipes have been laid to your point of use areas be it a machine or tools, you will want to have another filter at the point of use. Regardless of the age of your system, piping corrosion will happen leading to particulate in your air lines. You will want to filter this out prior to the final use of the air. The style and size of these filters should be determined at the point of use for the air. If your end use utilizes an EXAIR product – we recommend using our Automatic Filter Separators.

As the final step prior to use, it is recommended to have a pressure regulator and gauge on the line. Over time, every system will deplete air with small leaks, added users, or dirty filters. The most common cause of failure with EXAIR products, is actually lack of the appropriate air at the point of use.

Please keep in mind that this is a fairly simplistic explanation of a common Compressed Air System. Some systems have multiple receiving tanks, refrigerant coolers, dryers, and many different types of filters. The main goal is having enough clean, dry air to ensure that machines and tools function at peak performance.

Thank you for stopping by,

Brian Wages
Application Engineer
EXAIR Corporation
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Saving Compressed Air – The Fourth Utility

We all know the value of electric, water and gas but what about compressed air? Your compressed air system has an annual cost and deserves to be treated as a cost center. In my previous career, I was guilty of not having a budget for compressed air in my business plan and wish I knew then what I needed for a more efficient compressed air system. Compressed air carries a significant value and deserves to be a cost center with aggressive annual efficiency planning.

Unfortunately, several misconceptions about how to reduce energy costs through increased compressed air efficiencies have prevented many industrial operations from taking control of their compressed air energy costs. There are 2 main focuses about compressed air systems that can begin to reduce expenditures, improve the reliability of your systems and generate savings for future equipment improvements. First, you can look at energy savings in the compressor motors but this is a more complicated and more expensive endeavor that can be a next step when tackling compressed air savings head on. Second, the demand side of the compressed air system is where many efficiencies can be gained. A focus on leaks, storage, pressure and inefficient use are generally simple and inexpensive to address.

Increasing the pressure isn’t always the answer. In fact, frequently it is not. An efficient compressed air system is characterized by stable pressure levels. Steady pressure levels are achieved by addressing two things: air demand patterns and the minimum acceptable pressure level required for reliable production. Unfortunately, many operators who fail to properly diagnose the causes of system problems simply increase pressure to improve performance. Arbitrary increases to the pressure without understanding the root causes of performance issues can lead to increased energy costs. An audit completed by your compressed air specialist will reveal which aspects of your compressed system can be fine-tuned in order to reduce energy costs and increase reliability. Use of the “Six Steps to Optimizing Your Compressed Air System” will help achieve your goals for cost savings and efficiencies.

Begin with establishing a baseline for your system and learn what your typical air use looks like. This can be done with a flow meter installed at the compressor outlet. A flow meter is also useful at each machine or process demanding compressed air because they can (1) indicate if a machine or process is operating atypically and consuming more air than usual and (2) identify where high demand machines or processes are located in your facility.

It is estimated that up to 20% of compressed air produced by industrial air compressors is wasted due to leaks in typical facilities.¹ Approximately 20% of the air produced for industrial applications ends up being lost through leaks. The use of EXAIRs’ model 9061 Ultrasonic Leak Detector will enhance your efforts in finding leaks.

Choose engineered products to apply compressed air, these product have a focus on efficiency and outperform commercial products which do not concern themselves with air reduction.

When moving around your facility, look for applications of compressed air which can be turned off when personnel are on break or can be turned off in between parts. This step is very simple and can reap big savings.

Be sure to store compressed air close to high demand applications, this will prevent peaks and valleys in your compressed air demand which contributes toward less maintenance for your compressor.

Also lower your pressure at compressed air points of use. Keeping the pressure at the minimum pressure required for a successful application can also help keep system wide pressure to a minimum, which will increase lifetime of your compressor.

The good news is that, in most cases, lower energy costs are completely attainable for industrial operations that have not optimized their compressed air systems. To begin saving please contact EXAIR about compressed air products that can lower your compressed air costs today.

Eric Kuhnash
Application Engineer
Twitter: @EXAIR_EK

  1. Best Practices for Compressed Air Systems, second edition. From The Compressed Air Challenge.

Air Compressor Motors and Controls, Working Together.

One of the most important aspect of an efficient compressed air delivery system is effective utilization of compressor controls. The proper use of compressor controls is critical to any efficient compressor system operation. In order to reduce operating costs, compressor controls strategies need to be developed starting with minimizing the discharge pressure. This should be set as low as possible to keep energy costs to a minimum.

The compressor system is designed with maximum air demand in mind. During periods of lower demand compressor controls are used to coordinate a reduction in output that matches the demand. There are six primary types of individual compressor controls:

  1. Start/Stop – This is the most basic control. The start/stop function will turn off the motor in response to a pressure signal.
  2. Load/Unload – The motor will run continuously, but the compressor unloads when a set pressure is reached. The compressor will then reload at a specified minimum pressure setting.
  3. Modulating – Restricts the air coming into the compressor to reduce compressor output to a specified minimum. This is also known as throttling or capacity control.
  4. Dual/Auto Dual – On small reciprocating compressors, this control allows the selection of either Start/Stop or Load/Unload.
  5. Variable Displacement – Gradually reduces the compressor displacement without reducing inlet pressure.
  6. Variable Speed – Controls the compressor capacity by adjusting the speed of the electric motor.

All of these controls then control the compressor motors and they have several different starting methods.

There are several types of modern motor starters:

Full Voltage Starters: The original, and simplest method.  These are similar in theory to the old knife switches, but the operator’s hands aren’t right on the connecting switch.  Full line voltage comes in, and amperage can peak at up to 8 times full load (normal operating) amperage during startup.  This can result in voltage dips…not only in the facility itself, but in the neighborhood.  Remember how the lights always dim in those movies when they throw the switch on the electric chair?  It’s kind of like that.

Reduced Voltage Starters: These are electro-mechanical starters.  Full line voltage is reduced, commonly to 50% initially, and steps up, usually in three increments, back to full.  This keeps the current from jumping so drastically during startup, and reduces the stress on mechanical components…like the motor shaft, bearings, and coupling to the compressor.

Solid State (or “Soft”) Starters: Like the Reduced Voltage types, these reduce the full line voltage coming in as well, but instead of increasing incrementally, they gradually and evenly increase the power to bring the motor to full speed over a set period of time.  They also are beneficial because of the reduced stress on mechanical components.

The Application Engineering team at EXAIR Corporation prides ourselves on our expertise of not only point-of-use compressed air application & products, but a good deal of overall system knowledge as well.  If you have questions about your compressed air system, give us a call.

Jordan Shouse
Application Engineer

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Compressor Photo Credits to Bryan Lee, Creative Commons License