Optimizing Your Air Compression System Reduces Costs
Operating an air compression system consumes a significant amount of energy, so any improvements in efficiency will result in a better bottom line. For this reason, it is beneficial to evaluate and maintain your air system on a regular basis. In addition to ensuring that your air compression system uses less energy, regular evaluations and maintenance activities can optimize performance, prevent costly repairs and downtime, extend the service life of your air compressor and its components and increase productivity, all of which save money and boost earnings.
When trying to reduce the operating expenses associated with air compression systems, three areas of focus yield significant improvements: improving efficiency, re-thinking system design and prioritizing monitoring and maintenance activities.
Statistics show that only about half of a facility’s compressed air generation is used for its intended purpose, with the other half being wasted by leaks, inappropriate usage and artificial demand. Finding ways to curb inefficiencies is the fastest route to cutting costs. When looking to make efficiency improvements, key areas include minimizing waste and optimizing pressure.
- Minimizing waste: Since leaks are a major source of wasted air and energy (some estimates suggest that leaks account for 20% to 30% of a system’s air consumption), finding and fixing them should be a priority. While larger leaks can be found during a system walk through, ultrasonic leak detectors can help find smaller leaks or leaks in noisy areas. Ongoing inspections for leaks along with swift repair is the most effective way to prevent this considerable source of energy loss.
In addition to system leaks, air loss through condensate drains is another major source of waste that is often overlooked. While they are necessary for the removal of condensation generated by air compressors, if stuck in the open position both manual and timer drains will release air along with water. Instead, zero-loss or no-loss drains should be considered as they sense the presence of condensate, drain it only when needed and do so without the loss of air.
Inappropriate usage of compressed air is not uncommon, but it is expensive. Open blowing, personnel cooling and cabinet cooling are all common, but inappropriate uses for compressed air. These and other functions can most likely be served more cost effectively with a fan or blower.
Artificial demand refers to excess pressurized air that is in the system but is not being used, which means the system is constantly running in an effort to provide pressurized air, even when there is no demand. Using pressure regulators can help eliminate costly artificial demand. Along these lines, consider turning off the air compressor when it is not in use and/or during off hours. If you only use the air compressor 8 to 12 hours a day, five days a week, why leave it running 24/7? Making this change can cut energy consumption significantly.
- Optimize air pressure: It is not uncommon for pressure levels to be set to maximum thresholds to accommodate the needs of the highest-pressure applications, which may only account for a fraction of end uses. If high-pressure tools are only used some of the time, it is less costly to set the pressure level to that required by the majority of the end usage applications and increase pressure as needed. Another option, if the facility has multiple compressors, is to designate each compressor for different pressure levels to accommodate the various requirements.
Re-Examine System Design
Along with improving efficiency, evaluating the design of your air compression system can yield positive benefits. Although it may necessitate a small investment in labor or equipment, the achieved cost savings will often offset these expenses in the long run. Areas of consideration include air dryers, intake air, piping systems and waste heat.
- Dryers: Typically dryers are either refrigerated or desiccant. The best choice for a compressed air system is the one that achieves the required level of drying in the most efficient way. Often the most efficient option is to first use a refrigerant dryer and only apply further desiccant drying for parts of the system that must achieve lower dew point levels. This will also ensure that you aren’t over-drying pressurized air.
- Cooler intake air: Because cooler air requires less energy to compress, moving the intake to a cooler area can improve the system’s overall performance and save money on energy costs. A 20-degree drop in the temperature of intake air can reduce energy costs by nearly 4%.
- Piping systems: Examine piping systems to see if it is properly sized, there are unnecessary bends, kinks or very long runs. Reducing the distance air must travel and removing obstacles such as bends will permit easier airflow throughout the system and help eliminate pressure drops, while also reducing energy usage.
- Waste heat: All air compressors generate heat, but you can equip your system with attachments designed to convert the heat for other purposes. An air-cooled unit can provide warm air for ambient heating in a building, while a water-cooled unit can produce hot water for plant use. Since about 90% of generated heat can be captured and used elsewhere in the facility, recovering heat can provide impressive cost benefits.
Maintaining and Monitoring
By completing required maintenance on a regular basis and monitoring the system, energy and repair costs can be reduced. Checking filters and performing preventive maintenance should be a priority, as should updating the system’s monitoring technology.
- Clean and replace filters: Filters can easily become clogged, which, along with leaks, is one of the biggest energy wasters in compressed air systems. Dirty filters significantly reduce system efficiency and force it to work harder to move air through the system (also increasing the risk for contaminating the air and/or finished products). To avoid potential contamination issues and energy inefficiencies, filters should be inspected and cleaned on a regular basis. If they appear worn or are soiled with residue, it is time to replace them so that system efficiency can return to its highest level.
- Preventive maintenance: Along with regular filter cleanings, scheduling and performing preventive maintenance can help reduce energy costs and extend the life of the air compressor and its components. To maximize the functions of the air compression system, the unit itself, as well as its piping, motor fans, drip tray, belt and lubrication levels should be inspected periodically and tended to on a regular basis. Ensuring that all components are in working order will boost system reliability, lengthen the life of your equipment and prevent costly downtime and expensive repairs down the road.
- Monitoring: Analog gauges that provided simple measurements and required a technician to go into the field to read them are being replaced by digital tools that were developed to help diagnose, measure and monitor the condition of the air compression system. These tools collect valuable information about the performance and health of the system. The data can be used to optimize system performance, trend energy usage and repairs and spot early indicators of potential breakdowns, allowing users to plan and schedule maintenance activities prior to failure and increase system reliability.
By finding and fixing obvious sources of inefficiency, re-evaluating system design to ensure optimized performance, performing required maintenance, and digitally monitoring air compressor health and usage, it is possible to reduce the energy and repair costs associated with compressed air systems, improve reliability and increase uptime, all of which go a long way toward reducing operating expenses and increasing profits.
For more information on optimizing your air compression system to achieve cost savings, please contact John Henry Foster.