## Opportunities to Save On 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

## EXAIR’s Return on Investment For One Engineered Air Nozzle is Amazing!

Return on Investment (ROI) is a measure of the gain (preferably) or loss generated relative to the amount of money that was invested.  ROI is typically expressed as a percentage and is generally used for financial decisions, examining the profitability of a company, or comparing different investments.  It can also be used to evaluate a project or process improvement to decide whether spending money on a project makes sense.  The formula is shown below-

• A negative ROI says the project would result in an overall loss of money
• An ROI at zero is neither a loss or gain scenario
• A positive ROI is a beneficial result, and the larger the value the greater the gain

Example – installing a Super Air Nozzles (14 SCFM compressed air consumption) in place of 1/4″ open pipe (33 SCFM of air consumption consumption) .  Using the Cost Savings Calculator on the EXAIR website, model 1100 nozzle will save \$1,710 in energy costs. The model 1100 nozzle costs \$42, assuming a \$5 compression fitting and \$45 in labor to install, the result is a Cost of Investment of \$92.00. The ROI calculation for Year one is-

ROI = 1,759% – a very large and positive value.  Payback time is only 13 working days!

If you have questions regarding ROI and need help in determining the gain and cost from invest values for a project that includes an EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer

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## Why Start a Leak Prevention Program?

All compressed air systems will have some amount of leakage. It is a good idea to set up a Leak Prevention Program.  Keeping the leakage losses to a minimum will save on compressed air generation costs, and reduce compressor operation time which can extend its life and lower maintenance costs.

The Compressed Air Challenge estimates an individual compressed air leak can cost thousands of dollars per year when using \$0.07/kWh.

• 1/16″ diameter hole in excess of \$700/year
• 1/8″ hole in excess of \$2900/year
• 1/4″ hole in excess of \$11,735 per year

There are generally two types of leak prevention programs:

• Leak Tag type programs
• Seek-and-Repair type programs

Of the two types, the easiest would be the Seek-and-Repair method.  It involves finding leaks and then repairing them immediately. For the Leak Tag method, a leak is identified, tagged, and then logged for repair at the next opportune time.

A successful Leak Prevention Program consists of several important components:

• Document your Starting Compressed Air Use – knowing the initial compressed air usage will allow for comparison after the program has been followed for measured improvement.
• Establishment of initial leak loss – See this blog for more details.
• Determine the cost of air leaks – One of the most important components of the program. The cost of leaks can be used to track the savings as well as promote the importance of the program. Also a tool to obtain the needed resources to perform the program.
• Find the leaks – Leaks can be found using many methods.  Most common is the use of an Ultrasonic Leak Detector, like the EXAIR Model 9061.  See this blog for more details. An inexpensive handheld meter will locate a leak and indicate the size of the leak.

• Record the leaks – Note the location and type, its size, and estimated cost. Leak tags can be used, but a master leak list is best.  Under Seek-and-Repair type, leaks should still be noted in order to track the number and effectiveness of the program.
• Plan to repairs leaks – Make this a priority and prioritize the leaks. Typically fix the biggest leaks first, unless operations prevent access to these leaks until a suitable time.
• Record the repairs – By putting a cost with each leak and keeping track of the total savings, it is possible to provide proof of the program effectiveness and garner additional support for keeping the program going. Also, it is possible to find trends and recurring problems that will need a more permanent solution.
• Compare and publish results – Comparing the original baseline to the current system results will provide a measure of the effectiveness of the program and the calculate a cost savings. The results are to be shared with management to validate the program and ensure the program will continue.
• Repeat As Needed – If the results are not satisfactory, perform the process again. Also, new leaks can develop, so a periodic review should be performed to achieve and maintain maximum system efficiency.

An effective compressed air system leak prevention and repair program is critical in sustaining the efficiency, reliability, and cost effectiveness of an compressed air system.

If you have questions about a Leak Prevention Program or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer
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## Business Benefits From Compressed Air Efficiency

Use of compressed air, or “the fourth utility” as it’s called, is widespread in many industries.  How you use it in your business is important, for a couple of key considerations:

Monetary cost

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

If you want to go jot down some numbers from your compressor’s nameplate and your last electric bill, you can accurately calculate your actual cost.  Here’s the formula:

Taking our same 100HP compressor (105 bhp required,) fully loaded 85% of the time, and assuming the motor’s good (95% efficient):

(105 bhp X 0.746 X 4,160 hours X \$0.08/kWh X 0.85 X 1.0)÷ 0.95 =

\$23,324.20 actual annual compressed air cost

So, our estimate was within 4% of our actual…but the point is, \$22,000 to \$23,000 is a significant amount of money, which deserves to be spent as wisely as possible, and that means using your compressed air efficiently.  Engineered solutions like EXAIR Intelligent Compressed Air Products can be a major part of this – look through our Case Studies; implementing our products have saved companies as much as 60% on their compressed air costs.

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.

Russ Bowman
Application Engineer
EXAIR Corporation
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## Six Steps to Optimization, Step 4 – Turn Off Your Compressed Air When Not in Use

Step 4 of the Six Steps To Optimizing Your Compressed Air System is ‘Turn off the compressed air when it isn’t in use.’  Click on the link above for a good summary of the all the steps.

Two basic methods to set up a compressed air operation for turning off is the ball valve and the solenoid valve. Of the two, the simplest is the ball valve. It is a quarter turn, manually operated valve that stops the flow of the compressed air when the handle is rotated 90°. It is best for operations where the compressed air is needed for a long duration, and shut off is infrequent, such as at the end of the shift.

The solenoid valve offers more flexibility. A solenoid valve is an electro-mechanical valve that uses electric current to produce a magnetic field which moves a mechanism to control the flow of air. A solenoid can be wired to simple push button station, for turning the air flow on and off – similar to the manual valve in that relies on a person to remember to turn the air off when not needed.

Another way to use a solenoid valve is to wire it in conjunction with a PLC or machine control system. Through simple programming, the solenoid can be set to turn on/off whenever certain parameters are met. An example would be to energize the solenoid to supply an air knife when a conveyor is running to blow off parts when they pass under. When the conveyor is stopped, the solenoid would close and the air would stop blowing.

The EXAIR EFC (Electronic Flow Control) is a stand alone solenoid control system. The EFC combines a photoelectric sensor with a timer control that turns the air on and off based on the presence (or lack of presence) of an object in front of the sensor. There are 8 programmable on/off modes for different process requirements. The use of the EFC provides the highest level of compressed air usage control. The air is turned on only when an object is present and turned off when the object has passed by.

By turning off the air when not needed, whether by a manual ball valve, a solenoid valve integrated into the PLC machine control or the EXAIR EFC, compressed air usage will be minimized and operation costs reduced.

If you have questions about the EFC, solenoid valves, ball valves or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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## Cabinet Cooling with Thermostat Control and ETC

An EXAIR Cabinet Cooler® System with either the Thermostat Control or the Electronic Temperature Control (ETC) option includes a temperature measuring device that is used to control the operation of the Cabinet Cooler System to maintain the set-point temperature.

For most industrial enclosure cooling applications, a temperature of 95°F (35°C) is sufficient to be below the rated maximum operating temperature of the electrical components inside the cabinet. EXAIR Thermostats are preset to 95°F (35°C) and are adjustable. Maintaining the cabinet at 95°F (35°C) will keep the electronics cool and provide long life and reduced failures due to excessive heat. But if 95°F (35°C) is good, why not cool the cabinet to 70°F (21.1°C)?

When cooling an enclosure to a lower temperature, two things come into play that need to be considered. First, the amount of external heat load (the heat load caused by the environment) is increased. Using the table below, we can see the effect of cooling a cabinet to the lower temperature. For a 48″ x 36″ x 18″ cabinet, the surface area is 45 ft² (4.18 m²). If the ambient temperature is 105°F (40.55°C), we can find from the table the factors of 3.3 BTU/hr/ft² and 13.8 BTU/hr/ft² for the Temperature Differentials of 10°F (5.55°C) and 35°F (19.45°C). The factor is multiplied by the cabinet surface area to get the external heat load. The heat load values calculate to be 148.5 BTU/hr and 621 BTU/hr, a difference of 472.5 BTU/hr (119.1 kcal/hr)

The extra external heat load of 472.5 BTU/hr (119.1 kcal/hr) will require the Cabinet Cooler System to run more often and for a longer duration to effectively remove the additional heat. This will increase, unnecessarily, the operating costs of the cooling operation.

The other factor that must be considered when cooling an enclosure to a lower temperature is that the Cabinet Cooler cooling capacity rating is effected. I won’t go into the detail in this blog, but note that a 1,000 BTU/hr Cabinet Cooler (rated for 95°F (35°C cooling) working to cool a cabinet down to 70°F (21.1°C) instead of 95°, has a reduced cooling capacity of 695 BTU/hr (174 kcal/hr).  The reduction is due to the cold air being able to absorb less heat as the air rises in temperature to 70°F instead of 95°F.

In summary – operating a Cabinet Cooler System at 95°F (35°C) provides a level cooling that will keep sensitive electronics cool and trouble-free, while using the least amount of compressed air possible.  Cooling to below this level will result in higher operation costs.

If you have questions about Cabinet Cooler Systems or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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## Compressed Air Use in the Aerospace Industry

EXAIR’s products have been used for a very large selection of applications in almost every industry.  Today I want to highlight a few that pertain to the Aerospace Industry.

First – a quick lesson on how to access the Applications database– Be sure to Register and then Log In

From the main page, hover the mouse pointer over ‘KNOWLEDGE BASE‘ and the pop-up menu will appear as seen below.  Select ‘APPLICATIONS’

On the left hand side of the screen you will see a gray navigation pane that shows Application with a list underneath.  Scroll down the main page and you will see a second heading in the navigation pane labeled “Industry”.  You can select your industry from the list provided.  For today’s example we will select Aerospace.

Once the industry is selected there will be a new list of applications that are displayed in the center of the page.   Simply select the application you would like more information on and the details will display.

Below, we showcase the application from a machine manufacturer for the Aerospace industry.   This customer manufactured the production equipment of a flexible, porous material that is continuously passed through a wash tank prior to cutting to length.  They were interested in speeding the drying process of this strand, and considered blowing hot air onto it.  It was not feasible to install an electrically powered hot air blower or gun.  They needed an air flow of approximately 15 SCFM at 200°F, and had 70 psig air supply with a large volume available.  They utilized a Vortex Tube installed over the strand after it exited the dip tank.   The Vortex Tube was oriented with the hot air exhaust blowing on to the strand to dry the strand.  The customer stated that they not only met their expectations but exceeded the original hopes and were able to dry the product quicker and safer than expected.

This is just one of many applications that are showcased in the Application Database for the Aerospace industry.   Those are just a small sampling of the thousands of applications that can be researched through the database.  If you would like to share your application to the database, feel free to contact an Application Engineer.

If you have questions about any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
Find us on the Web