Don’t blow money on compressed air leaks. According to the U.S. Department of Energy, approximately 30% of compressed air produced is lost to leaks—an annual estimated cost of $3.2 billion in wasted energy.
A large manufacturing facility, for instance, can save nearly $200,000 per year simply by implementing a regular air leak check and repair program. This seems like a sensible best practice in theory, however, it’s an opportunity that is quite often overlooked.
Compressed Air Primer
Commonly referred to as the “fourth utility,” compressed air is vital to many industries, like manufacturing and research and development (R&D). The Compressed Air & Gas Institute notes many benefits of using compressed air, including its easy, versatile application. It’s cost effective and can be generated on-site. Compressed air is safe—crucial in combustible, explosive, or wet environments where electric motors pose a hazard—and air tools are typically lighter, safer, and easier to operate than electric motors in these environments.
Compressed air does require significant energy to be produced—only 5-10% of the energy input to a compressor goes toward the productive use of compressed air, while the remaining 90% of is wasted energy due to heat generated by the compression cycle in the compressor.
Neglecting air leaks can have significant negative impacts on both costs and energy conservation efforts.
Bad News: The Negative Ripple Effect of a Leak
The annual cost of air leaks in America alone is staggering. If an air leak is audible, then it’s likely costing at least $500 per year. A quarter-inch in diameter leak can cost well over $1,600 annually. But money is not the only issue.
Air leaks affect:
Comfort: Air leaks increase humidity, and audible leaks produce hisses and whines that can be a persistent nuisance to occupants. Some leaks have been so bad that the resulting noise required a site to reclassify a space as a noise hazard, requiring workers to wear safety earmuffs. Wouldn’t fixing the leak have made more sense?
Air Quality: When there are leaks, oil particles from the compressor’s oil lubrication system are released into the air.
The Environment: Oil-based compressed air systems create large quantities of oil-infused condensate, which can contaminate waterways.
Efficiency: Air motors are eight times more expensive than electric motors, and leaks affect air pressure, requiring the system to work harder to maintain pressure. Lost pressure means less efficient air tools, which impacts production.
Efficiency is also tied to the building’s costs and environmental impacts.
System Lifespan: Leaks force equipment to cycle more frequently, reducing life span and requiring additional maintenance and unscheduled downtime.
Most often, leaks develop at the fittings or as rubber hoses degrade. However, it’s not unheard of for workers to contribute to the problem by creating holes in the system to create a personal cooling system. This practice can contribute to thousands of dollars a year in energy waste, in addition to the above-mentioned factors, so it’s important everyone in the facility understands how important it is to help identify and stop air leaks.
Good News: Savings Opportunities
A regular air leak detection and repair program should be part of a facility’s routine preventative maintenance. The program should consist of an air leak survey to identify and tag air leaks followed by systematically repairing the leaks, prioritizing the most severe. As leaks are inevitable, the process should repeat with a survey every six months.
Toolkit
Equipment for identifying leaks can be acquired for a modest cost—no more than a few hundred dollars for any item. Tools include:
- An ultrasonic leak detector, which can detect leaks from up to 30 feet away with precision, using ultrasound technology to hear even the tiniest of leaks.
- A noise level meter, which measures the severity of the leak in decibels.
- And a manometer, which measures drops in air pressure across compressor air filters.
Survey
- Detect: Conducting a survey should start from the compressor room and cover the entire facility, starting with using the ultrasonic leak detector to locate leaks. Scan pipes, hoses, fittings, pneumatic controls, regulators, etc.
- Measure: Once a leak is identified, use a noise level meter to measure the leak. Tip: Do not hold the meter right up to the leak to avoid inaccurate readings. The device should measure from approximately 6 inches away from the source of the leak.
While ultrasonic leak detectors operate at distance, noise level meters include telescoping attachments so they can get up close to the leak, even at heights.
- Tag: Tag the leak with an air leak tag—these tags are typically brightly colored, so they are easy to find and serve as a reminder to fix the leak.
- Calculate: The U.S. Department of Energy offers free resources to calculate the savings of fixing a leak, in both dollars and reduced carbon dioxide (CO2) emissions. Using MEASUR, one can input some information, such as annual operating hours, types of controls, and electricity costs, and the system will run the calculation. This resource is scientifically backed and updated regularly.
- Fix: Think of it this way: every day that goes by without fixing an air leak equals wasted money. Once leaks are identified and tagged, prioritize the largest leaks and work down from there.
- Repeat the process every six months.
Additional Savings
Ensuring filters are clean helps improve air flow so that the compressors do not have to work as hard to maintain the air pressure in pounds per square inch (PSI). Using a manometer to scan compressor filters can help identify pressure issues.
Installing variable frequency drives on compressor motors can help manage load, improve efficiency and ultimately save up to 60% of the energy output.
Energy from heat of compression can be recovered to heat air or water utilized elsewhere in the building systems, such as HVAC.
It’s important to reiterate how vital it is to fix the leaks after they are identified. The larger the leak, the more energy is being wasted every day!
As these practices are enacted, the compressor PSI settings can be reduced. Since less energy is being wasted, the compressor does not have to work as hard to maintain desired pressure. Reducing PSI demands not only saves energy but also extends the life of the compressor with less downtime and repair/maintenance costs.
Breaking News: Don’t Wait
The opportunity is there. Unfortunately, a lot of facilities don’t take the time to identify and repair leaks. Even modest adjustments can have major impacts. A facility in Illinois produced $175,000 in cost savings after reducing compressed air waste by 7%. And there’s still room for improvement—even new facilities experience about 25% leakage. By continually detecting and correcting leaks, facilities can manage energy waste and save tens of thousands of dollars annually.
The tools are attainable and simple to use. The resources are there to calculate and prove the impact. Savings are there for anyone willing to do the work.
