Determining Leakage Rate and Cost of Compressed Air Leaks

The electricity costs associated with the generation of compressed air make it the most expensive utility within an industrial environment. In a   poorly maintained compressor system, up to 30% of the total operational costs can be attributed simply to compressed air leaks. While this wasted energy is much like throwing money into the air, it can also cause your compressed air system to lose pressure. This can reduce the ability of the end use products to function properly, negatively impacting production rates and overall quality. Luckily, it’s quite easy to estimate the leakage rate and is something that you should be including in your regular PM schedule.

According to the Compressed Air Challenge, a well-maintained system should have a leakage rate of less than 5-10% of the average system demand. To estimate what your leakage rate is across the facility, first start by shutting off all of the point of use compressed air products so that there’s no demand on the system. Then, start the compressor and record the average time it takes for the compressor to cycle on/off. The compressor will load and unload as the air leaks cause a pressure drop from air escaping. The percentage of total leakage can be calculated using the following formula:

Leakage % = [(T x 100) / (T + t)]


T = loaded time (seconds)

T = unloaded time (seconds)

The leakage rate will be given in a percentage of total compressor capacity lost. This value should be less than 10% for a well-maintained system. It is not uncommon within a poorly maintained system to experience losses as high as 20-40% of the total capacity and power.

A leak that is equivalent to the size of a 1/16” diameter hole will consume roughly 3.8 SCFM at a line pressure of 80 PSIG. If you don’t know your company’s air cost, a reasonable average is $0.25 per 1,000 SCF. Let’s calculate what the cost would be for a plant operating 24hrs a day, 7 days a week.

3.8 SCFM x 60 minutes x $0.25/1,000 SCFM =


$0.06 x 24 hours =

$1.44/ day

$1.44 x 7 days x 52 weeks =

$524.16 per year

A small leak of just 3.8 SCFM would end up costing $524.16. This is just ONE small leak! Odds are there’s several throughout the facility, quickly escalating your operating costs. If you can hear a leak, it’s a pretty severe one. Most leaks aren’t detectable by the human ear and require a special instrument to convert the ultrasonic sound created into something that we can pick up. For that, EXAIR has our Model 9061 Ultrasonic Leak Detector.

Model 9061 ULD w/ parabola attachment checking for compressed air leaks

Implementing a regular procedure to determine your leakage rate in the facility as well as a compressed air audit to locate, tag, and fix any known leaks should be a priority. The savings that you can experience can be quite dramatic, especially if it’s not something that has ever been done before!

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD

EXAIR Digital Flow Meters

A topic that we’ve talked about here on the EXAIR blog discusses the costs of compressed air and how to use it more efficiently. How can you determine the costs of your compressed air? The first step you’ll need to take is to put a number to how much compressed air you are currently using. In order to do that you’ll need a measurement tool such as the EXAIR Digital Flowmeter.

EXAIR Digital Flow Meters

The Digital Flowmeter is available from stock for use on Schedule 40 pipe with sizes ranging from ½”-4” I.D. Sizes up to 8” for Schedule 40 and ¾”-4” for copper pipe are also available. Metric sizes are also available for 25mm, 40mm, 50mm, 63mm, 76mm, and 101mm. With a digital readout display, it’s easy to accurately monitor your compressed air usage throughout the facility. Creating a baseline of your usage will allow you to understand your compressed air demand, identify costly leaks, and replace inefficient air products.

The Digital Flowmeter installs in minutes with help from a drill guide and locating fixture to assist in mounting the Digital Flowmeter to the pipe. Two flow sensing probes are inserted into the drilled holes in the pipe. The meter then seals to the pipe once tightened. There is no need to cut, weld, or do any calibration once it is installed. With blocking rings also available, installation can be permanent or temporary. Below is a easy to follow video on how to install EXAIR’s Digital Flow Meter!

The newest addition to this product line is the Digital Flowmeter with wireless capability. Using a ZigBee® mesh network protocol, data is transmitted to an Ethernet connected gateway. This allows you to mount the Digital Flowmeter in areas that you may not be able to easily access and wirelessly monitor and graph the usage with the EXAIR Logger software. Take a peek at this video blog for a demonstration of the use of a wireless Digital Flowmeter software to compare an open pipe to an engineered Air Nozzle.

Wireless output gives you the freedom to track air usage data from any computer!

In addition to communicating wirelessly with the gateway, the Digital Flowmeters can “piggyback” off of each other to extend their range. Each meter has a range of 100’. Using multiple Digital Flowmeters within the same ZigBee® mesh network, data can be passed from meter to meter to extend the distance over which the meters can operate. These can be installed on each major leg of your compressed air system to continuously monitor usage throughout the facility.

If you’d rather go with a hard-wired data collection method, the Digital Flowmeter is also available with a USB Data Logger. Simply remove the Data Logger from the Digital Flowmeter and connect it to the USB port of your computer. The data can then be viewed directly in the accompanying software or exported into Microsoft Excel.

Add a Data Logger for easy Value Tracking

Two special flow meter options we now offer are the Pressure Sensing Digital Flowmeters, and the Hot Tap Digital Flowmeters!

Pressure Sensing Digital Flowmeters help by generating a pressure and consumption profile of a system can help to pinpoint energy wasters such as timer-based drains that are dumping every hour versus level based drains that only open when needed. Hot Tap Digital Flowmeters offer a way to install a flow meter on a pipe that is currently under pressure. It uses a series of valves and mufflers to maintain a safe working environment for the installer.

If you’d like to get a clear view of your compressed air usage, give us a call. An Application Engineer will be happy to work with you and get the proper Digital Flowmeters installed in your facility!

Jordan Shouse
Application Engineer

Send me an Email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS

Know How Much Money You Can Save with EXAIR’s Efficiency Lab

Free testing. Verifiable data. EXAIR Efficiency Lab.

When it comes to buying new gear for any kind of outdoor hobby the research almost becomes a full-time job to decided what to get. When I’m hanging 200 ft. in the air off of a single rope, I want to make sure that my harness, rope, and all my other gear is top notch and not going to fail me as my literal life is hanging on the line. Sometimes it would be nice to have a professional climber standing there telling you all of the pros and cons, what they like and dislike about it, and weather it’s worth the buy. Outdoor gear is expensive and climbing equipment is no exception, in an ever-changing world of innovation new things are coming out every week and is just to hard for one person to keep up with.

Similarly, EXAIR has multiple product lines, many new products, and countless applications for our products. That is where our Application Engineers come in; as experts on our products and their applications we can provide in-depth knowledge on the various uses and expected outcomes. 

EXAIR’s Products in action

EXAIR has been making compressed air products since 1983, and have since created a culture of making high quality, safe, and efficient compressed air products. With this in mind we started the Efficiency Lab program for people to take advantage to test your current pneumatic blow-off device and compare it to an EXAIR Intelligent Compressed Air product. We will generate a detailed report on our findings and send it to you for your review. This free service provided to U.S. and Canadian companies allows people to test and look into possible upgrades and cost savings.

During my time as a project and process engineer at Valeo and Tyson I wish I had known about this service.  The Efficiency Lab allows you to look at what your current process is, whether it is an open-ended pipe or some other nozzle and have EXAIR compare it to an EXAIR product for free. Its like getting a free inspection of all your gear and having an expert help you find the best replacement if needed.

You may be wondering why we offer this service; it’s simple, compressed air can be expensive and we want to save you money. Not only are open ended pipes unsafe and can violate OSHA Standards on both dead-end pressure and noise level, but they also use a lot of compressed air. To operate an 1/8” open pipe you are looking at over $2000 a year for just one pipe; there isn’t a single plant that is just going to use one pipe. That is a lot of money that can add up over time, which could easily be saved by changing out what you are using.

The Efficiency Lab is quite simple to use. The simplest way is to contact us (my info below) and we can exchange the information needed to get your product into EXAIR. Once received, we will proceed. We will then calibrate the equipment and standardized procedures to test for noise level, air consumption, and force generated. Based off of this information we will recommend a similar product. Don’t be afraid, let us take care of the hard part of choosing which product is best for your application. If you cannot send any product in, use our  Product Efficiency Survey to provide as many details as possible. 

If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook

Exploring Optimization: Standards And Certifications For Compressed Air Audits

EXAIR Corporation has devoted almost 37 years to manufacturing engineered products aimed at the most efficient, quietest, and safest use of compressed air.  Sometimes, a caller has recognized that an open pipe blow off, for example, is loud, wasteful, and unsafe, and just wants to install an engineered product that they know will be an improvement.  They may not be interested in precisely quantifying the savings…they’ll just notice that their lone air compressor runs less, and their electric bill isn’t as high anymore.

Others, however, may have a compressed air system that comprises multiple compressors, with advanced controls, and they may have specific operational goals in regard to how the individual compressors are loaded and controlled, or maybe even eliminating the need to run particular compressors all the time…or at all.

The skills & knowledge necessary to handle such a task are within the confines of discipline of mechanical engineering, but oftentimes, specialized training is needed to effectively conduct an audit in order to formulate an execute such an optimization plan.  If you’re interested in pursuing this training, or working with trained personnel, here’s a brief description of the training that’s available, and how you can find people that have been through it:

  • The American Society of Mechanical Engineers (ASME) publication “Guidance for ASME EA-4, Energy Assessment for Compressed Air Systems” details the requirements for performing an audit.  Since there are so many configurations of compressed air systems, it’s not a “step by step” procedure, but it IS handy for developing one, if you know how.  Speaking of which…
  • The Compressed Air & Gas Institute (CAGI) offers training & certification in two categories:
    • Certified Compressed Air System Specialists (CCASS) – these are qualified experts who have demonstrated competence (by means of a comprehensive examination) in skills and abilities relating to the design, service, sales, and installation of compressed air systems & equipment.
    • Certified Compressed Air System Assessors (CCASA) – in addition to CCASS certification, these individuals has passed another comprehensive examination, verifying their knowledge and skills as practitioners performing assessments (audits) of compressed air systems.

Both of these certifications comply with the ISO 17024 Conformity Assessment standard, which governs General Requirements for Bodies Operating Certification of Persons in any field of endeavor.  This means that, not only have certified personnel all passed the same tests regardless of where they are, but the tests they’ve passed meet stringent standards for examining knowledge level and competence in these fields.

Bottom line: if you want an in-depth, accurate evaluation of the efficiency of your compressed air system, experts are available.  The Compressed Air & Gas Institute even publishes directories so you can find them in your area.

Russ Bowman
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook