Optimizing Compressed Air Systems

Although it is often viewed as an essentially free resource, compressed air (CA) is anything but free. In fact, in many industrial plants, air compressors consume more energy than any other single end use. And once the air is compressed to the desired pressure, it often has to be dried and cooled before it is sent through the distribution system to the end use, requiring even more energy (Figure 1). According to the U.S. Department of Energy (DOE), CA accounts for 10 percent of industrial electricity consumption.

Figure 1: Compressed air system diagram
This shows a typical compressed air system with compression, cooling, storage, and distribution equipment.

Fortunately, most industrial facilities have many opportunities to improve CA-system efficiency through measures with rapid paybacks. A DOE study found that, in small to midsize industrial facilities, about 15 percent of CA-system energy use can be saved through actions that pay for themselves in less than two years. In larger facilities, payback periods can be even shorter, with savings that can range from 30 to 60 percent of existing system usage. Although a comprehensive optimization of your CA system usually requires the services of a trained professional, there are a number of very cost-effective steps you can take today, without the aid of an expert, to make your system more efficient. These steps include reducing system pressure to the minimum necessary to get the job done, identifying and fixing leaks, eliminating inappropriate uses of CA, improving system control, and implementing a regular maintenance plan.

The concepts presented briefly here (and many more) are discussed in greater detail in Improving Compressed Air System Performance: A Sourcebook for Industry, published by the DOE.

Reduce System Pressure
Find and Eliminate Leaks
Identify and Eliminate Inappropriate Uses of Compressed Air
Improve System Control
Perform Regular Maintenance
Resources for Further Information