How to Estimate Leaks and the Impact upon a Compressed Air System

In today’s age where compressed air is often referred to as the 4th utility in an industrial manufacturing facility, leaks throughout the system can add up to serious financial losses. It has been estimated that leaks can waste as much as 20-30 percent of an air compressor output.


Not only are leaks a source of wasted energy, they can also contribute to other losses such as:

  • Causing a drop in system pressure, resulting in air tools to function less efficiently
  • Increasing the air compressor on/off cycles which shortens the life of it and other components in the system
  • Increased maintenance costs and more planned downtime for the maintenance to be performed
  • A need to install of additional compressors to make up for the inefficiencies caused by leaks

For compressors that have start/stop controls – the below formula can be used to estimate the leakage rate in the system-

Leakage Equation 1

To use the above formula, the compressor is started when there is no demand on the system –  all air operated equipment and devices are turned off.  As the air escapes the system through the leaks, the system pressure will drop and the compressor will turn on and cycle to bring the pressure back up to the operating level. Measurement of the average time (T) of compressor run duration, and time (t) of the system pressure to drop to the set-point can be plugged into the formula and a Leakage Percentage established.

Another method to estimate the leakage rate is shown below-

Leakage Equation 2

The above method requires knowledge of the total system volume, which includes downstream air receivers, air mains, and all piping.  To perform the check, bring the system pressure up the normal operating pressure (P1) and then measure the time (T) it takes for the system to drop to pressure (P2) which is generally around half the operating pressure.  The 1.25 is a correction factor to normal system pressure, since the leakage rate will be less as the system pressure is lowered.

A leakage rate greater than 10% typically shows that there are areas of improvement (leaks that can be identified and repaired)

Any leakage testing and estimating should be preformed regularly, at least each quarter, so as to minimize the effect of any new system leaks. The tests are only one part of a leak detection and repair program. The best way to detect leaks is the use of ultrasonic leak detector (shown below.)  To learn more about the EXAIR model 9061 Ultrasonic Leak Detector, check out this blog that was previously published.


If you have questions about compressed air systems, or would like to talk about any of the EXAIR Intelligent Compressed Air® Products, 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 
Like us on Facebook
Twitter: @EXAIR_BB

The Value Of A Pressure Regulator At Every Point Of Use

EXAIR Pressure Regulator

To understand the value of a having a Pressure Regulator at every point of use we should start with identifying the two types of Pressure Regulators, Direct Acting & Pilot Operated.  Direct Acting are the least expensive and most common (as shown above), however they may provide less control over the outlet pressure, especially if they are not sized properly.  However when sized properly they do an outstanding job.  Pilot Operated Regulators incorporate a smaller auxiliary regulator to supply the required system pressure to a large diaphragm located on the main valve that in turn regulates the pressure.  The Pilot Operated Regulators are more accurate and more expensive making them less attractive to purchase.  The focus of this Blog will be on the Direct Acting Pressure Regulator.

The Direct Acting Pressure Regulator is designed to maintain a constant and steady air pressure downstream to ensure whatever device is attached to it is operated at the minimum pressure required to achieve efficient operation.  If the end use is operated without a regulator or at a higher pressure than required, it result’s in increased air demand and energy use. To clarify this point, if you operate your compressed air system at 102 PSI it will cost you 1% more in electric costs than if the system was set to run at 100 PSI! Also noteworthy is that unregulated air demands consume about 1% more flow for every PSI of additional pressure.  Higher pressure levels can also increase equipment wear which results in higher maintenance costs and shorter equipment life.

Sizing of the Air Regulator is crucial, if it is too small to deliver the air volume required by the point of use it can cause a pressure drop in that line which is called “droop”.  Droop is defined as “the drop in pressure at the outlet of a pressure regulator, when a demand for compressed air occurs”.  One commonly used practice is to slightly oversize the pressure regulator to minimize droop.  Fortunately we at EXAIR specify the correct sized Air Regulator required to operate our devices so you will not experience the dreaded “droop”!

Standard Air Knife Kit
EXAIR Standard Air Knife Kit Which Incudes Shims, Properly Sized Pressure Regulator & Filter Separator

Another advantage to having a Pressure Regulator at every point of use is the flexibilty of making pressure adjustments to quickly change to varying production requirements.  Not every application will require a strong blast sometimes a gentle breeze will accomplish the task.  As an example one user of the EXAIR Super Air Knife employs it as an air curtain to prevent product contamination (strong blast) and another to dry different size parts (gentle breeze) coming down their conveyor.

EXAIR products are highly engineered and are so efficient that they can be operated at lower pressures and still provide exceptional performance!  This save’s you money considering compressed air on the average cost’s .25 cents per 1000 SCFM.

Super Air Knife Performance
EXAIR Super Air Knife Performance Specifications At 5 Different Pressures.

If you would like to discuss Air Regulators or quiet and efficient compressed air devices, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook


ROI – Is it Worth the Investment?

Any time you’re planning to purchase something, the return on investment (ROI) is an important thing to consider. Whether you’re considering buying new windows to improve on your heating and cooling costs, looking at replacing outdated appliances with newer and more efficient models, or purchasing an Intelligent Compressed Air Product, how quickly that product will pay for itself can help you to make the right decision.


Last year, my wife and I purchased our first home. In the backyard, was a nice, big in-ground pool. While it was something we did look for, it requires a bit of maintenance during the summer months to keep the water clear and things running smoothly. Who wants to swim in a pool ridden with dirt, leaves, bugs, and debris floating around? Certainly not me, which meant I needed to spend some time brushing the sides of the pool and vacuuming to keep everything clean. For our first season, we elected to tackle this task manually. Not only was this time consuming, but it was also not very effective. To brush the sides and steps, skim, and vacuum took about 2 hours each time. I was doing this 2x per week to keep everything looking good. Over the course of a 15-week pool season here in Southwest Ohio, I spent approximately 60 hours just keeping the pool clean.

We were interested in the robotic pool vacuums available at our local pool supply store, but we balked at the initial price of them. After spending all this time doing it myself, I began to think that it would pay for itself relatively quickly (depending on how much I valued my own labor 😊). Allocating the cost of the robotic vacuum over the six-year life expectancy, as well as taking into consideration how much time I had spent cleaning the previous year, made this decision much more palatable. We went ahead, bit the bullet, and purchased one for this season. I must say, just two weeks in and my pool is cleaner than it ever was last year. We’ve only run it twice!! It only takes 5 minutes to connect and drop in. I reduced my time spent from 4 hours per week to 10 minutes per week. Consider me a happy consumer.

If you follow the EXAIR Blog, you’ll know that one of our primary focuses is saving customers money by reducing their compressed air operating cost. Recently, I wrote a blog post about a customer that replaced an inefficient solution with some EXAIR Super Air Knives. Let’s take a look and see how quick these knives were able to pay for themselves:

The previous solution consisted of (3) nozzles operated at 50 psig, consuming a total of 51 SCFM. This line was run continuously for (1) 8-hour shift, (5) days per week. The average cost for compressed air is $0.25 per 1,000 SCF (based on $0.08/kWh).

51 SCFM x 60 mins x 8-hours x $0.25/1000 = $6.12 per day

Replacing the inefficient nozzles with (3) Model 110003 Super Air Knives reduced the overall consumption to 17.1 SCFM when operated at 50 psig.

17.1 SCFM x 60 mins x 8-hours x $0.25/1000 = $2.05 per day

This led to a total savings of $4.07 per day, just by swapping out the inefficient product with the EXAIR Super Air Knives. So how quickly will they pay for themselves? Each Model 110003 Super Air Knife carries a list price of $199.00. Since we were using (3) on each line, their total investment per line was $597.00 USD.

$597.00/4.07 = 146.68 (147 days)

Inefficient blowoff

On the 147th day (less than 30 weeks, based on a 5-day workweek), the Super Air Knives have paid for themselves. Afterward, that $4.07/day/line goes straight to the bottom line. You’ll be hard pressed to find many products that will pay for themselves in less than one year, but at EXAIR we see this day in and day out. Stop throwing your money out the window with inefficient compressed air solutions. Reach out to an EXAIR Application Engineer and see how quickly your blowoffs can start paying YOU.

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD

Little things add up image courtesy of Nic McPhee via creative commons license

EXAIR’s Industry Leading Super Air Knife Saves You Money

One common application that we get calls for each and every day centers around maximizing compressed air efficiency. I recently got to work with a customer who was using an inefficient blowoff method and was looking to replace it with an engineered compressed air solution. They had a total of (8) extrusion lines, each with (3) modular-hose style flat nozzles installed. Before a cooling bath they had one nozzle remove some of the heat, then as the extruded material exits the water bath another (2) nozzles blowoff any residual water. They were maxing out their compressor’s peak operating capacity and pressure drops across the system were causing problems elsewhere in other processes.


They were operating each of the flat nozzles at 50 psi using a total of 17 SCFM per nozzle. We first calculated how much air the current method was using. The extrusion lines were run for one full 8-hr shift per day:

17 SCFM/nozzle x 3 nozzles/line = 51 SCFM per extrusion line

51 SCFM x 60 mins x 8hrs x 5 days x 50 weeks = 6,126,000 SCF

The extrusion lines accommodated product that ranged from 1”-2.5” wide. They wanted one single solution to use across all different products. We settled on (3) of our 110003 3” Super Air Knives. Let’s take a look at the compressed air requirement for (3) 110003 Super Air Knives, also operated at 50 psig.

A Super Air Knife will consume 1.9 SCFM/inch when operated at 50 psig:

1.9 SCFM/inch x 3 inches (per knife) = 5.7 SCFM/knife

5.7 SCFM x (3) total knives = 17.1 SCFM

17.1 SCFM x 60 mins x 8hrs x 5 days x 50 weeks = 2,052,000 SCF

Total savings per extrusion line – 6,126,000 SCF – 2,052,000 SCF = 4,074,000 SCF

4,074,000 SCF x 8 extrusion lines = 32,592,000 SCF

By replacing the (3) inefficient nozzles with EXAIR’s Super Air Knives, a whopping 4,074,000 SCF of compressed air is saved each year. With (8) total lines, this equates to a total of 32,592,000 SCF of compressed air. Most companies will know the cost of their compressed air usage per CFM, but a cost of ($0.25/1000 standard cubic feet) is a good baseline to use.

($.25/1000 SCF) x 32,592,000 SCF = $8,148.00 USD

By replacing (3) inefficient nozzles across all (8) extrusion lines with EXAIR’s industry leading Super Air Knife, they were able to save a total of $8,148.00 per year. In as little as (6) months, the Super Air Knives will have already paid for themselves!!

If you’ve been maxing out your compressed air system, don’t necessarily assume you need to increase your overall capacity. Put in a call to an EXAIR Application Engineer and we can take a closer look at the ways your using your compressed air throughout the facility. By replacing some inefficient methods with an engineered solution, we can help you save air and money!

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD

Compressor Control – A Way to Match Supply to Demand

Rarely does the compressed air demand match the supply of the compressor system. To keep the generation costs down and the system efficiency as high as possible Compressor Controls are utilized to maximize the system performance, taking into account system dynamics and storage. I will touch on several methods briefly, and leave the reader to delve deeper into any type of interest.

air compressor

  • Start/Stop – Most basic control –  to turn the compressor motor on and off, in response to a pressure signal (for reciprocating and rotary type compressors)
  • Load/Unload – Keeps the motor turning continuously, but unloads the compressor when a pressure level is achieved.  When the pressure drops to a set level, the compressor reloads (for reciprocating, rotary screw, and centrifugal type)
  • Modulating – Restricts the air coming into the compressor, as a way to reduce the compressor output to a specified minimum, at which point the compressor is unloaded (for lubricant-injected rotary screw and centrifugal)
  • Dual/Auto Dual – Dual Control has the ability to select between Start/Stop and Load /Unload control modes.  Automatic Dual Control adds the feature of an over-run timer, so that the motor is stopped after a certain period of time without a demand.
  • Variable Displacement (Slide Valve, Spiral Valve or Turn Valve) – Allows for gradual reduction of the compressor displacement while keeping the inlet pressure constant (for rotary screw)
  • Variable Displacement (Step Control Valves or Poppet Valves) – Similar effect as above, but instead of a gradual reduction, the change is step like (for lubricant injected rotary types)
  • Variable Speed – Use of a variable frequency AC drive or by switched reluctance DC drive to vary the speed of the motor turning the compressor. The speed at which the motor turns effects the output of the system.

In summary – the primary functions of the Compressor Controls are to match supply to demand, save energy, and protect the compressor (from overheating, over-pressure situations, and excessive amperage draw.) Other functions include safety (protecting the plant and personnel), and provide diagnostic information, related to maintenance and operation warnings.

If you would like to talk about compressed air or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_BB

Replacing a 1/4″ Open Copper Tube With a 2″ Flat Super Air Nozzle Leads To Quick ROI

The generation of compressed air accounts for approximately 1/3 of all energy costs in an industrial facility and up to 30% of that compressed air is wasted through inefficient operation. Open pipes or homemade blowoffs waste a ton of compressed air, resulting in high operating costs. By replacing these devices with an energy efficient, engineered solution, you can reduce this waste and dramatically cut energy costs.

For example, let’s look at the average operating costs for a single 1/4″ open copper tube. (If you don’t know you current energy costs, a reasonable average to use is $ 0.25 per every 1,000 SCF used, based on $ 0.08/kWh.

1/4″ Copper tube

A single 1/4″ open copper tube consumes 33 SCFM @ 80 PSIG and costs roughly $ 0.50 per hour to operate. (33 SCF x 60 minutes x $ 0.25 / 1,000 = $ 0.50). For an 8 hour shift, the total cost would be $ 4.00 ($ 0.50 x 8 hours = $ 4.00).

If we were to replace the 1/4″ open copper tube with our Model # 1122 2″ Flat Super Air Nozzle with 1/4″ FNPT inlet, the air consumption would be reduced to 21.8 SCFM @ 80 PSIG. This may not seem like much of an air usage reduction, but when you look at the monetary, total cost of ownership for purchasing and operating the nozzle, the savings can quickly add up.

2″ Flat Super Air Nozzle

The operating cost for a 2″ Flat Super Air Nozzle with 1/4″ FNPT inlet is $ 0.33 per hour (21.8 SCF x 60 minutes x $ 0.25 / 1,000 = $ .033) or $ 2.64 per 8 hour shift ($ 0.33 x 8 hours = $ 2.64).

We can now compare the operational cost between the 2 devices:

1/4″ open copper tube operating costs:
$ 0.50 per hour
$ 4.00 per day (8 hours)

2″ Flat Super Air Nozzle operating costs:
$ 0.33 per hour
$ 2.64 per day (8 hours)

Cost Savings:
$ 4.00 / day (open copper tube) –  $ 2.64 / day (2″ Flat Super Air Nozzle) = $ 1.36 savings per day

The Model # 1122 2″ Flat Super Air Nozzle has a list price $ 67.00 USD.

ROI or Return On Investment calculation:
$ 67.00 (Cost) / $ 1.36 (savings per day) = 49.26 days.

The 2″ Flat Super Air Nozzle would pay for itself in just over 49 days in operation. This is the savings for replacing just ONE 1/4″ open copper tube with an engineered solution! In most industrial plants, there could be several of these which presents even more opportunities to reduce the overall operational costs.

Our focus here at EXAIR is to improve the overall efficiency of industrial compressed air operating processes and point of use compressed air operated products. If you are looking to reduce compressed air usage in your facility, contact an application engineer and let us help you optimize your current system.

Justin Nicholl
Application Engineer

EXAIR’s EFC is THE Way to Save Compressed Air


Compressed air is the most expensive utility for most industrial facilities. The energy costs associated with the generation of compressed air can be very high. Because of this, EXAIR manufactures a wide range of products geared towards reducing your overall compressed air consumption.

The best way to save compressed air is to simply turn it off when it’s not being used. This might seem pretty simple, but there may be processes in your facility where this couldn’t be achieved by just turning a valve. In applications where product is traveling along a conveyor, and must be dried, cooled, or blown off, there is likely some spacing in between the parts. It isn’t necessary to keep the blowoff running constantly if there’s periods of intermittent spacing. To help reduce the overall load on the air compressor, implementing a solution to shut the air off in between each part can have a dramatic impact. EXAIR’s Electronic Flow Control, or EFC, is designed to improve efficiency by reducing overall compressed air usage. It utilizes a photoelectric sensor that detects when the part is present. When it’s not, it triggers a solenoid valve to close and shut off the compressed air supply.



Let’s take a look at an example that shows just how much air (and $$) an EFC can save. We had a manufacturer of car bumpers that was using a Model 112060 60” Super Ion Air Knife supplied at 40 PSIG to remove dust prior to a painting operation. The bumpers were moving at about 10’/minute and had 1’ of spacing in between each part. The bumpers are only under the blowoff for 10 seconds, while 6 seconds passed with no part present. With a (3) shift operation, this translates to 1,440 minutes of nonstop compressed air usage per day.

A 60” Super Ion Air Knife will consume 102 scfm at 40 PSIG. Their current method was using a total of 146,880 SCFM.

102 SCFM x 1,440 minutes = 146,880 SCF

With the EFC installed, the air was shut off for 6 seconds reducing the airflow by 37.5%. With the EFC installed, the compressed air consumption per day was reduced to 91,800 SCF.

146,880 SCF x .625 = 91,800 SCF

As a general rule of thumb, compressed air costs $0.25/1,000 SCF. By saving 55,080 SCF per day, this manufacturer was able to save $13.77 per day. Since this was a 24 hour/day shift running 7 day/week, total savings for the year came in at $5,012.28. This easily recoups the costs of the EFC and then begins to pay you in less than 6 months.

55,080 SCF x ($0.25/1,000 SCF) = $13.77

$13.77 x 7 days/week x 52 weeks/year = $5,012.28

The EFC models available from stock can accommodate flows up to 350 SCFM. For applications requiring more compressed air, EFCs with dual solenoids are also available. If you have an application in one or more of your processes where intermittent compressed air use could help save you money, give us a call. We’d be happy to take a look at the application and help determine just how quickly the EFC could start paying YOU!

Tyler Daniel
Application Engineer
E-mal :
Twitter: @EXAIR_TD