Several factors influence the choice between one centralized installation versus several smaller decentralized compressors. Factors to consider include:
Costs of a production shutdown
Reliable availability of electrical power
Compressed air system costs
Available floor space
Size of plant and distance between compressed air points of use
In a centralized installation, compressed air is distributed from a central compressor installation to areas of the plant requiring compressed air. The centralized compressor installation normally uses fewer large-sized compressors and dryers versus a distributed system, but there are advantages and disadvantages to both installations. A centralized compressor installation is often the preferred solution because:
Installation of equipment tends to be less expensive because all compressed air equipment is set up in one area and piping only needs to run to the points of use
A central installation involves lower monitoring and maintenance costs because the networking cable needs to run only to one area
Having all the equipment in one area allows for better opportunities for recovering energy
Filters, coolers and other auxiliary equipment, along with common air intake, can be optimally dimensioned
The compressor area is more easily outfitted with noise reduction measures
A system with several decentralized compressors can also be the preferred choice for certain applications that require the air supply to be nearby. Decentralized solutions involve a smaller, simpler compressed air distribution system. They can be used to maintain pressure in a system that experiences a large pressure drop when intermediate processes draw too much air. In situations with extremely short peaks of air consumption, it helps to position buffers and air receivers to mitigate any issues. Decentralized systems are particularly useful if a customer has varying demands of air quality. For example, in an auto body shop, they may need dry, oil-free air for a paint booth or breathing air application; however, they may also use compressed air for air tools or filling tires. It would be more expensive over time to generate the premium oil-free air used in the tools than it would to have a separate oil-injected system.
Locating smaller compressors next to their points of use also reduces the risk of leaks in the air system and minimizes wasted money. Large plants with equipment spread further apart require long pipe runs, which are more susceptible to developing leaks versus shorter pipe runs.
Although decentralized installations can benefit certain applications, they sometimes have difficulty inter-regulating the compressed air supply and maintaining a reserve capacity. Fortunately, with today’s advanced technology, there are modern compressors with fully-integrated compressed air conditioning equipment and high-performance silencing measures. These compressors can be installed to reduce compressed air distribution costs and eliminate the need for a separate building or an extension to the separate compressor room.