Leaks can be discussed quite frequently around industrial environments. These can be refrigerant leaks, water leaks, gas leaks, even information leaks. All of these leaks have one thing in common, they all cost the company money in the end. I often think about several classic cartoons when I hear about leaks being fixed as they are found. They can become a little overwhelming like the “Squirrel” from the movie Ice Age 2.
When it comes down to it, not many leaks create good results, that is why I want to take a second and educate on the costs your facility may be seeing from compressed air leaks. The leaks within an industrial environment can often account for up to 30% of the total compressed air generated.
So let’s take a look at that, the cost of compressed air is derived from the kWh cost the facility pays to the utility company. Here in the Midwest the average cost is around $0.08 / kWh. The equation to convert this to cost per cubic foot of compressed air is shown below. This formula assumes that the compressor generates four standard cubic feet of compressed air per horsepower of compressor. Again this is an industry acceptable assumption.
The size of a leak will determine how much compressed air is wasted, most of these leaks are not even to the audible range for the human ear which leads them to be undetected for long periods of time. A leak that is equivalent to a 1/16″ diameter orifice can result in an annual loss of more than $836.50 USD. While the scale of this number when compared to the annual revenue of a company may be small, the fact remains that this single leak would more than likely not be the only one. This isn’t the only way leaks will cost money though.
Leaks can also generate false demand which can result in pressure drops on a system. When the pressure on a production line drops this could result in unscheduled shutdowns. Often, when a pressure drop is observed the quick answer is to increase the header pressure which causes even more energy to be utilized and even more compressed air will be pushed out of these leaks. That increase in system pressure comes at a price as well. When increasing a system pressure by 2 psi the compressor will consume an additional percent of total input power. This again will hit the bottom line and result in lower efficiency of operation for the facility.
If you hear that distinct hiss of compressed air leaks when you are walking through your facility, or even if you don’t hear the his and you know that a leak detection action plan is not being practiced and want to find out the best ways to get one in place, contact us. We are always willing to help you determine how to lower the leaks in your facility as well as reduce the system pressure required to keep your lines up and running by implementing engineered solutions at the point of use.
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 EXAIRModel 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.
Leaks are a hidden nuisance in a compressed air system that can cause thousands of dollars in electricity per year. These leaks on average can account for up to 30% of the operation cost of a compressed air system. A leak will usually occur at connection joints, unions, valves, and fittings. This not only is a huge waste of energy but it can also cause a system to lose pressure along with lowering the life span of the compressor since it will have to run more often to make up for the loss of air from the leak.
There are two common ways to calculate how much compressed air a system is losing due to leaks. The first way is to turn off all of the point of use compressed air devices; once this has been complete turn on the air compressor and record the average time that it takes the compressor to cycle on and off. With the average cycle time you can calculate out the total percentage of leakage using the following formula.
The second method is to calculate out the percentage lost using a pressure gauge downstream from a receiver tank. This method requires one to know the total volume in the system to accurately estimate the leakage from the system. Once the compressor turns on wait until the system reaches the normal operating pressure for the process and record how long it takes to drop to a lower operating pressure of your choosing. Once this has been completed you can use the following formula to calculate out the total percentage of leakage.
The total percentage of the compressor that is lost should be under 10% if the system is properly maintained.
Once the total percentage of leakage has been calculated you can start to look at the cost of a single leak assuming that the leak is equivalent to a 1/16” diameter hole. This means that at 80 psig the leak is going to expel 3.8 SCFM. The average industrial air compressor can produce 4 SCFM using 1 horsepower of energy. Adding in the average energy cost of $0.25 per 1000 SCF generated one can calculate out the price per hour the leak is costing using the following calculation.
If you base the cost per year for a typical 8000 hr. of operating time per year you are looking at $480 per year for one 1/16” hole leak. As you can see the more leaks in the system the more costly it gets. If you know how much SCFM your system is consuming in leaks then that value can be plugged into the equitation instead of the assumed 3.8 SCFM.
If you’d like to discuss how EXAIR products can help identify and locate costly leaks in your compressed air system, please contact one of our application engineers at 800-903-9247.
Cody Biehle Application Engineer EXAIR Corporation Visit us on the Web Follow me on Twitter Like us on Facebook
If you’re a regular reader of the EXAIR blog, you’re likely familiar with our:
This guideline is as comprehensive as you want it to be. It’s been applied, in small & large facilities, as the framework for a formal set of procedures, followed in order, with the goal of large scale reductions in the costs associated with the operation of compressed air systems…and it works like a charm. Others have “stepped” in and out, knowing already where some of their larger problems were – if you can actually hear or see evidence of leaks, your first step doesn’t necessarily have to be the installation of a Digital Flowmeter.
Here are some ways you may be able to “step” in and out to realize opportunities for savings on your use of compressed air:
Power: I’m not saying you need to run out & buy a new compressor, but if yours is
aging, requires more frequent maintenance, doesn’t have any particular energy efficiency ratings, etc…you might need to run out & buy a new compressor. Or at least consult with a reputable air compressor dealer about power consumption. You might not need to replace the whole compressor system if it can be retrofitted with more efficient controls.
Pressure: Not every use of your compressed air requires full header pressure. In fact, sometimes it’s downright detrimental for the pressure to be too high. Depending on the layout of your compressed air supply lines, your header pressure may be set a little higher than the load with the highest required pressure, and that’s OK. If it’s significantly higher, intermediate storage (like EXAIR’s Model 9500-60 Receiver Tank, shown on the right) may be worth looking into. Keep in mind, every 2psi increase in your header pressure means a 1% increase (approximately) in electric cost for your compressor operation. Higher than needed pressures also increase wear and tear on pneumatic tools, and increase the chances of leaks developing.
Consumption: Much like newer technologies in compressor design contribute to higher efficiency & lower electric power consumption, engineered compressed air products will use much less air than other methods. A 1/4″ copper tube is more than capable of blowing chips & debris away from a machine tool chuck, but it’s going to use as much as 33 SCFM. A Model 1100 Super Air Nozzle (shown on the right) can do the same job and use only 14 SCFM. This one was installed directly on to the end of the copper tube, quickly and easily, with a compression fitting.
Leaks: These are part of your consumption, whether you like it or not. And you shouldn’t like it, because they’re not doing anything for you, AND they’re costing you money. Fix all the leaks you can…and you can fix them all. Our Model 9061 Ultrasonic Leak Detector (right) can be critical to your efforts in finding these leaks, wherever they may be.
Pressure, part 2: Not every use of your compressed air requires full header pressure (seems I’ve heard that before?) Controlling the pressure required for individual applications, at the point of use, keeps your header pressure where it needs to be. All EXAIR Intelligent Compressed Air Product Kits come with a Pressure Regulator (like the one shown on the right) for this exact purpose.