Opportunities to Save On Compressed Air

Since air compressors use a lot of electricity to make compressed air, it is important to use the compressed air as efficiently as possible.  EXAIR has six simple steps to optimize your compressed air system.  (Click HERE to read).  Following these steps will help you to cut your overhead costs and improve your bottom line.  In this blog, I will cover a few tips that can really help you to save compressed air.

To start, what is an air compressor and why does it cost so much in electricity?  There are two types of air compressors, positive displacement and dynamic.  The core components for these air compressors is an electric motor that spins a shaft.  Like with many mechanical devices, there are different efficiencies.  Typically, an air compressor can put out anywhere from 3 SCFM per horsepower to 5 SCFM per horsepower.  (EXAIR settles on 4 SCFM/hp as an average for cost calculations.)  Equation 1 shows you how to calculate the cost to run your air compressor.

Equation 1:

Cost = hp * 0.746 * hours * rate / (motor efficiency)

where:

Cost – US$

hp – horsepower of motor

0.746 – conversion KW/hp

hours – running time

rate – cost for electricity, US$/KWh

motor efficiency – average for an electric motor is 95%.

As an example, a manufacturing plant operates a 100 HP air compressor in their facility.  The cycle time for the air compressor is roughly 60%.  To calculate the hours of running time per year, I used 250 days/year at 16 hours/day.  So operating hours equal 250 * 16 * 0.60 = 2,400 hours per year.  The electrical rate for this facility is $0.08/KWh. With these factors, the annual cost to run the air compressor can be calculated by Equation 1:

Cost = 100hp * 0.746 KW/hp * 2,400hr * $0.08/KWh / 0.95 = $15,077 per year in just electrical costs.

There are two major things that will rob compressed air from your system and cost you much money.  The first is leaks in the distribution system, and the second is inefficient blow-off devices.   To address leaks, EXAIR offers an Ultrasonic Leak Detector.  The Ultrasonic Leak Detector can find hidden leaks to fix. That quiet little hissing sound from the pipe lines is costing your company.

A University did a study to find the percentage of air leaks in a typical manufacturing plant.  For a poorly maintained system, they found on average that 30% of the compressor capacity is lost through air leaks.  Majority of companies do not have a leak preventative program; so, majority of the companies fall under the “poorly maintained system”.  To put a dollar value on it, a leak that you cannot physically hear can cost you as much as $130/year.  That is just for one inaudible leak in hundreds of feet of compressed air lines.  Or if we take the University study, the manufacturing plant above is wasting $15,077 * 30% = $4,523 per year.

The other area to check is air consumption.  A simple place to check is your blow-off stations.  Here we can decide how wasteful they can be.  With values of 4 SCFM/hp and an electrical rate of $0.08/KWh (refence figures above), the cost to make compressed air is $0.25 per 1000 ft3 of air.

One of the worst culprits for inefficient air usage is open pipe blow-offs.  This would also include cheap air guns, drilled holes in pipes, and tubes.  These devices are very inefficient for compressed air usage and can cost you a lot of money.  As a comparison, a 1/8” NPT pipe versus an EXAIR Mini Super Air Nozzle.  (Reference below).  As you can see, by just adding the EXAIR nozzle to the end of one pipe, the company was able to save $1,872 per year.  That is some real savings.

 By following the Six Steps to optimize your compressed air system, you can cut your energy consumption, improve pneumatic efficiencies, and save yourself money.  With the added information above, you can focus on the big contributors of waste.  If you would like to find more opportunities to save compressed air, you can contact an Application Engineer at EXAIR.  We will be happy to help.

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

Compressed Air Flow Meter With Wireless Capability Makes Monitoring Demand Easy

Would you like the ability to monitor your plants compressed air usage from one convenient location?  If the answer is yes, EXAIR has just the solution to fit your needs, EXAIR’s Digital Flow Meter with Wireless Capability.

wirelessdfmpr2_1670x574

Wireless capability is an option for EXAIR’s Digital Flowmeter’s.  It is the efficient way to monitor your compressed air consumption wirelessly utilizing the ZigBee® mesh network.  This is accomplished by a module located within the meter that transmits data to an ethernet connected gateway.  Each meter has a range up to 100 feet (30 meters), however the ZigBee mesh network protocol is very versatile as it allows data to also be transmitted from meter to meter, effectively extending the distance over which the system can operate.  So large facilities with great distances to cover are not a problem.

The Digital Flowmeter with Wireless Capability is offered in a kit with a wireless output flow meter, wireless to ethernet gateway, drill guide, power supplies for each component, and ethernet cable for gateway connectivity.  These kits are best suited for new installations.  They are also available without a gateway if you are simply adding an additional meter to a pre-existing Gateway in your plant.  EXAIR simplifies this process by configuring each gateway to communicate with the flowmeter to provide the necessary communication for monitoring your system.  Models from 1/2″ to 4″  iron pipe are in stock. 5″, 6″ iron pipe,  copper pipe ranging from 3/4″ to 4″ diameter and aluminum pipe from 25mm to 101mm diameter are available with short lead time as a special product offering.  Each digital flowmeter is calibrated for the pipe size to which it is mounted and the large digital display shows air use in either SCFM or Cubic Meters per Hour.

Digital Flow Meter Kit
Digital Flowmeter w/ Wireless Capability, Gateway, and Drill Guide Kit

Setting up the EXAIR Digital Flow Meter with Wireless Capability is super easy.  After the meter is installed download the graphing software from our website and install on your computer.  There is also a video tutorial posted in the previous blog from Tyler Daniel, Video Blog: EXAIR’s New Wireless Digital Flowmeter Installation.

The Digital Flowmeter with Wireless Capability is designed for permanent or temporary mounting to the pipe.  It requires the user to drill two small holes through the pipe using the optional drill guide which includes the drill bit and locating fixture.  The two flow sensing probes of the flowmeter are inserted into these holes.  The unit seals to the pipe once the clamps are tightened.  No cutting, welding, adjustments or calibration are needed, ever!  If the unit needs to be removed, blocking rings are available for the 1/2″ to 4″  iron pipe sizes from stock with other sizes available on short lead time as special orders.

If you have questions on Digital Flowmeter’s, Digital Flowmeter’s with Wireless Capability or need expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you!

Steve Harrison
Application Engineer
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What Makes A Compressed Air System “Complete”?

It’s a good question.  When do you know that your compressed air system is complete?  And, really, when do you know, with confidence, that it is ready for use?

A typical compressed air system. Image courtesy of Compressed Air Challenge.

Any compressed air system has the basic components shown above.  A compressed air source, a receiver, dryer, filter, and end points of use.   But, what do all these terms mean?

A compressor or compressed air source, is just as it sounds.  It is the device which supplies air (or another gas) at an increased pressure.  This increase in pressure is accomplished through a reduction in volume, and this conversion is achieved through compressing the air.  So, the compressor, well, compresses (the air).

A control receiver (wet receiver) is the storage vessel or tank placed immediately after the compressor.  This tank is referred to as a “wet” receiver because the air has not yet been dried, thus it is “wet”.  This tank helps to cool the compressed air by having a large surface area, and reduces pulsations in the compressed air flow which occur naturally.

The dryer, like the compressor, is just as the name implies.  This device dries the compressed air, removing liquid from the compressed air system.  Prior to this device the air is full of moisture which can damage downstream components and devices.  After drying, the air is almost ready for use.

To be truly ready for use, the compressed air must also be clean.  Dirt and particulates must be removed from the compressed air so that they do not cause damage to the system and the devices which connect to the system.  This task is accomplished through the filter, after which the system is almost ready for use.

To really be ready for use, the system must have a continuous system pressure and flow.  End-use devices are specified to perform with a required compressed air supply, and when this supply is compromised, performance is as well.  This is where the dry receiver comes into play.  The dry receiver is provides pneumatic capacitance for the system, alleviating pressure changes with varying demand loads.  The dry receiver helps to maintain constant pressure and flow.

In addition to this, the diagram above shows an optional device – a pressure/flow control valve.  A flow control valve will regulate the volume (flow) of compressed air in a system in response to changes in flow (or pressure).  These devices further stabilize the compressed air system, providing increased reliability in the supply of compressed air for end user devices.

Now, at long last, the system is ready for use.  But, what will it do?  What are the points of use?

Points of use in a compressed air system are referred to by their end use.  These are the components around which the entire system is built.  This can be a pneumatic drill, an impact wrench, a blow off nozzle, a pneumatic pump, or any other device which requires compressed air to operate.

If your end use devices are for coating, cleaning, cooling, conveying or static elimination, EXAIR Application Engineers can help with engineered solutions to maximize the efficiency and use of your compressed air.  After placing so much effort into creating a proper system, having engineered solutions is a must.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE