Simple Adjustments Can Boost the Efficiency of Your Air System
As a proven way to drive tools, equipment and processes, industrial air systems are widely used throughout the manufacturing industry. The downside to these powerful air systems is that they are notoriously inefficient and can be expensive to operate. Fortunately, efficiency and control improvements are available to correct many of the issues that lead to system inefficiency and can significantly reduce the costs associated with running your air system, while also improving its performance.
What Makes Air Systems Inefficient?
While leaks are often the biggest culprit in the inefficiency of air systems, they are certainly not the only issue. Poor intake air quality, pressure drops, inconsistent maintenance, or inadequate controls can all contribute to higher electric bills and poor system performance. For this reason, it’s essential to take a holistic view of the air system, including the air compressor, supply lines and auxiliary equipment, to determine the root cause of inefficiencies that may be plaguing your air system and costing you money. Below we’ll discuss common issues and suggest simple adjustments that will help boost system efficiency
Leaks are a significant source of wasted energy in a facility’s air system, potentially squandering as much as 20% to 30% of the compressor’s output, according to the U.S. Department of Energy (DOE). In addition to wasting energy, leaks are associated with operational issues such as fluctuating system pressure and decreased service life. Couplings, hoses, tubes, fittings, pipe joints, quick disconnects, filter, regulator and lubricators (FRLs), actuators, condensate traps, valves, flanges, packings, thread sealants and point-of-use devices are common areas of leakage.
The good news is that finding and fixing leaks can reduce energy loss to less than 10% of the compressor output and the best way to do so, according to the DOE, is using an ultrasonic acoustic leak detector, which recognizes the hissing sounds associated with air leaks. Once you locate a leak, simple fixes might include tightening connections or replacing couplings, hoses, joints, traps and drains and fitting them using proper thread sealant.
Improve Intake Air Quality
An air compressor’s efficiency can be negatively impacted if the incoming air is too hot, contains impurities or has high humidity. Reducing the temperature of the intake air will go a long way toward lowering the electric bill. Some ways to do this might include moving the compressor intake to a shady outdoor area, or improving the compressor room ventilation. Dirty air is another no-no when it comes to system efficiency. Clean intake air moves smoothly throughout the system; however, dirt, dust and impurities trapped in the air filter will restrict airflow, reducing compressor efficiency. Inspecting and replacing inlet filters on a regular basis will ensure filters are free of dirt that will restrict airflow.
High levels of humidity and chemical gasses at the compressor intake should also be avoided. They can lead to contamination and corrosion inside the compressor leading to unnecessary wear and tear and increased maintenance costs.
Pressure drops are a major contributor to system inefficiency. They are often the result of unnecessarily complex or undersized compressed air distribution piping. For example, if the air must flow through complicated, long or zig-zagging runs of pipe or if the pipe diameter is too small, the resulting friction between the air and pipe will restrict airflow and create pressure loss. Simplifying the piping route or replacing too-small piping with the appropriate size will allow air to run smoothly and with less pressure loss. Using automated filtration systems and smart sensors that monitor for pressure drops is also helpful. In addition, switching from timer drains to zero-loss drains will help ensure that pressure is not lost when draining moisture out of the system.
A storage tank or receiver can also be added in an effort to reduce pressure drop because it will offset short-term demand cycling and reduce on/off cycling, while also preventing system pressure from dropping below minimum pressure requirements when demand is high.
In addition to inspecting pipes for blockages and changing filters regularly, aftercoolers and dryers also need attention because they are critical to controlling dew point and preventing corrosion and contamination within the air system. Preventative maintenance schedules and regular system checkups that include cleaning the aftercoolers, dryer condenser coils and drains, compressor oil testing, filter replacement, and leak detection will help ensure efficiency and reliable operation of the air compressor and the overall air system.
Embrace Control Technologies
Compressed air systems rely on controls to keep the compressor running at minimum pressure while still keeping up with system demands. In other words, controls will reduce compressor output when the demand pressure reaches a pre-set level and will increase output when demand pressure drops below a pre-set level. To meet compressed air system demand, start and stop controls will turn the compressor on or off, load/no load controls will load and unload the compressor, and modulating controls will manage the output flow by adjusting the compressor inlet valve. In many cases, variable displacement or modern variable speed drive controls will allow the compressor to operate more efficiently at varying loads. Air systems with multiple compressors may benefit from master or networked compressor controls, sometimes including a plant demand flow control. These items can coordinate all necessary functions to keep compressed air running efficiently according to demand while reducing the likelihood of demand-related pressure drops and fluctuations.
Recycle Wasted Heat
During daily, standard operations, air compressors generate a lot of heat, which usually goes to waste. However, technologies are available to capture that heat and use it elsewhere in the facility to heat open warehouse spaces or water for bathrooms or processes in an effort to improve the facility’s overall efficiency and offset some of the costs associated with running the compressor and air system.
Performing one, a few or all of these adjustments will go a long way toward boosting the efficiency of your air system, while saving money on the electric bill and improving overall operation. To learn about these or other air system efficiency improvements, please contact a representative at JHFOSTER.