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)]

Where:

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/hour

$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.

ULD_Pr
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
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

EXAIR Supports your ROI Efforts

EXAIR not only has products that will reduce your air consumption, cost and noise levels but also has the tools to help you calculate the annual savings and Return on Investment (ROI). Sometimes you have the materials in house to make your own pneumatic tools so you get that piece of pipe in the maintenance crib, drill several holes and connect your compressed air. It works, your team is proud of the solution and everyone moves on to the next fire, right?

Several projects later you notice that your compressed air usage seems very high so a team is assembled and challenged with a cost savings program geared towards compressed air savings. EXAIR is the company that can help. We have Intelligent Compressed Air Products, Free Expert Technical Help and savings calculators that can be used to show the savings in your reports and presentations. EXAIR’s cost savings calculator will simplify the savings for each process you study and help your efforts in purchase justifications.

We have several examples of helping our customers save money such as this blog by one of our talented Application Engineers. You will realize more than cost savings as you should also see significant sound reductions and safety improvements as all of our products meet or exceed OSHA standard 29 CFR 1910.95 (a) which outlines allowable noise exposure for personnel and OSHA standard 29 CFR1910.242 (b) Dead End Pressure requirements.

When you begin compressed air cost savings program and have questions as to where to start, how to calculate and how to prepare your justifications please give EXAIR a call and talk with one of our many talented Application Engineers. EXAIR’s Intelligent Compressed Air products and Application Engineers will support all your efforts to decrease compressed air usage, reduce sound levels and increase the safety of your environment.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

6 Steps to Air Savings: Step 1 – Measure!

Six Steps to Optimizing Your Compressed Air System

If you’re a follower of the EXAIR Blog, you’re probably well aware that compressed air is the most expensive utility in an industrial environment. The average cost to generate 1000 Standard Cubic Feet of compressed air is $0.25. If you’re familiar with how much air you use on a daily basis, you’ll understand just how quickly that adds up. To make matters worse, many compressed air systems waste significant amounts of compressed air just through leaks. According to the Compressed Air Challenge, a typical plant that has not been well maintained will likely have a leak rate of approximately 20%!! Good luck explaining to your finance department that you’re carelessly wasting 20% of the most expensive utility. Step 1 of the 6 steps to optimizing your compressed air system is to measure the air consumption to find sources that consume a lot of air.

In order to have an understanding of your compressed air usage across various processes and in your entire facility, you have to measure. Without a measurement of usage, there’s no way to determine your actual costs or evaluate opportunities for savings. To do so, EXAIR offers a range of Digital Flowmeters in sizes from as small as ½” Schedule 40 iron pipe and up to 4” Schedule 40 pipe from stock. Larger sizes and pipes calibrated for use on copper or metric pipe are also available.

The Digital Flowmeter provides a digital readout of the exact amount of compressed air being used. Many companies will install the DFM on each major leg of their air distribution system to allow for constant monitoring and provide a benchmark of compressed air usage.

Each meter has a built in LED display that provides the volume of air moving through the pipe in SCFM, m3/hr, or m3/min. Two small probes are inserted into holes in the pipe (drill guide kit w/ drill bit included) to detect the airflow. The unit seals to the pipe once the clamps are tightened. (If the DFM ever needs to be removed, EXAIR also offers blocking rings to seal off the holes) No cutting, welding, adjustments or calibrations are ever required.

In addition to the standard Digital Flowmeter itself, it’s also offered with wireless capability to transmit the data back to your PC, or via USB Data Logger. Both of these options will allow you to track usage over time and upload that data into an Excel spreadsheet.

EXAIR’s Digital Flowmeter w/ USB Data Logger

If you’re “flying blind” when it comes to understanding your costs of compressed air in your facility, this is the first step. Contact an EXAIR Application Engineer today to get started. We’ll be happy to help you identify areas where you could take advantage of simple savings.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

Turn It Off: Saving Compressed Air The Easy Way

A major benefit to utilizing compressed air is the speed at which it can be shut off and re-energized for use – in fact, this can be done instantaneously. Shutting down the supply of compressed air to an application while it is not needed can drastically reduce the compressed air consumption of the process. This is an easy remedy that can produce significant savings.

Think about a place where you have a compressed air blow off with spaces between the parts or dwell times in conveyor travel. What about break times, do operators continue to keep the air on when they leave for a break or even worse, for the day?

Step number four in EXAIR’s Six Steps to Optimization is:

A simple manual ball valve and a responsible operator can provide savings at every opportunity to shut down the airflow. But an automated solution is a no-brainer and can provide significant savings.

Quarter Turn Ball Valves are low-maintenance and easy to install/use.

For a more automated approach, you can add a solenoid valve that would tie into your existing PLC or e-stop circuit, into your compressed air supply lines to aid in turning the compressed air on and off.

For an automated on/off solution can be found by using the EXAIR EFC (Electronic Flow Control). The EFC is made to accept 110V or 220V AC, and convert it to 24V DC to operate a sensor, timer, and solenoid valve. Its multiple operating modes allow you delay on, delay-off, and delay on/off among others. The operating mode can then be set to the specific time necessary for a successful application.

The spaces between parts can be turned into money saved. Every time you reach the end of a batch run, the EFC can turn the air off. You can also add solenoid valves and run them from your machine controls. If the machine is off, or the conveyor has stopped – close the solenoid valve and save the air. The modes are all defined in the video below.

So, take a look, or even better a listen, around the plant and see what you can find that could benefit from turning the air off; even if it is just for a moment it will help put money back into your bottom line.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF