Get the most out of your compressed air system
While we only work about 40 hours a week, a compressed air system is, in most instances, much more dependable and loyal, taking breaks only for routine scheduled maintenance.
There is no shortage of stories. Through either anecdotes or instances our engineers have personally witnessed while conducting plant tours or compressed air system assessments, we see and hear all about inappropriate uses of compressed air. Some of them are rather comical, some may be urban myths, and some simply make an engineer’s blood boil. But they are all an unnecessary waste of energy and resources that can have a dramatic impact on productivity—and your bottom line.
Compressed air systems are a critical function in many manufacturing facilities. Consider that there are 168 hours in a week. While we only work about 40 (if we’re lucky), a compressed air system is, in most instances, much more dependable and loyal, taking breaks only for routine scheduled maintenance. It’s not uncommon for systems to be active in excess of 120 hours a week. Follow these simple tips and you’ll find there are a number ways to help save energy (and money) while increasing the efficiency of the compressed air system at your facility.
Fix existing leaks
About 80% of air leaks detected in a compressed air system are not audible. To help minimize these problems and maximize efficiency, a third-party auditor is likely needed to help detect leaks that even the most observant workers can’t detect. Even the smallest of leaks can prove to be a big drain on resources. A single quarter-inch air leak at 100 psi will cost more than $2,500 a year.
Depending on pressure requirements and energy costs, by some accounts, this can cost as much as $8,000 a year per leak. Piping systems more than five years old have been shown to exhibit leaks of up to 25%. Some simple math shows that these leaks, when left to compound upon each other, add up quickly.
In addition to fixing leaks, preventing new ones is a proactive way to ensure that a compressed air system is running at maximum efficiency. A clean, dry pipe is a good illustration that the system is producing a clean, quality airflow with no potential corrosion issues. Issues such as improperly filtered air, dust and corrosion-inducing moisture, and sludge in the pipes are a fast track to leaks and can compromise a system’s efficiency and the goods it helps produce.
Identify and eliminate inappropriate compressed air usage
We define inappropriate compressed air usage as any application that could otherwise be conducted more efficiently or effectively by a method other than compressed air. Sure, there are instances where jury-rigging tools or “creative solutions” may get the job done and even draw chuckles and quiet admiration from coworkers, but the fact is they just waste money.
At one manufacturing facility, employees used air from the motion-activated, above-door fan—powered by a 200 hp compressor—to dry door frames and rid them of dust when they were moved from outside storage to inside the manufacturing facility. Switching to a low-pressure blower achieved the same results while saving enormous amounts of energy.
Other common examples of compressed air misuse include open hose nozzles, using expensive compressed air for personal cooling (this can potentially be very dangerous, and a fan is far more efficient), and a number of improvised tools that are used to remove dust and debris. We all applaud ingenuity and innovation, but some of the best intentions often fail to exhibit a smart use of resources. There are likely more energy-efficient solutions that can be incorporated that achieve the same results.
One facility manager took it upon himself to lower energy costs but wanted to avoid the ire of workers who complained about pressure drops. To combat this, he embarked on his own artificial demand experiment and lowered his facility’s compressor output by 1 psi each day until he received a complaint about low system pressure; even then, he’d simply raise the pressure back up 1 more psi.
Care to guess what happened? Beginning at about 110 psi, the manager dropped his system’s output by more than 10%—dropping it to 99 psi—before fielding a single complaint. That simple, single step helped save the facility tens, if not hundreds of thousands of dollars. By some estimates, as much as 25% of compressor output is wasted through artificial demand.
According to a recent study conducted by the U.S. Dept. of Energy, compressed air accounts for 10% of all electricity use in U.S. manufacturing. By most assessments, even the most efficient compressed air system ultimately delivers 10% to 15% of all energy input as compressed air. When combined with leaks, inefficient design, incorrect uses, and poor maintenance it totals more than $3.2 billion annually in wasted energy use in the United States.
Taking individual steps to help reduce this energy draw has a significant impact collectively, which saves money, energy, and resources. Schedule an air assessment to see how much you stand to save.
For a free copy of Atlas Copco's 136-page Compressed Air Manual, 7th Edition, please send an e-mail to paul.humphreys(at)us.atlascopco.com. Put “Manual—Plant Engineering” in the subject line and provide your delivery address in the body of the e-mail.