Understanding Air Compressor Intercooler Maintenance

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Functions of Intercoolers

The air compressor intercooler’s main function is to cool air before it enters the next stage of compression. The higher density of cool air makes it easier to compress than hot air. Ideally, the air should be as close to the ambient air temperature as possible. Typically, the intercooler is able to cool the compressed air within 20-30 degrees of the ambient air temperature.

The cooling process begins by passing cool water into the intercooler and manifold through tubes. Fins attached to the tubes add stability and aid in increasing the cooling surface area. Using 3/8” tubing in place of 5/8” tubing allows for a larger quantity of tubes to be included in the bundle, which is another way to increase the surface area.

Moisture from the lower velocity air condensates and separates from the air as it passes through the intercooler. The moisture drains from the compressor through a valve located at the bottom of the intercooler enclosure. This method of removal prevents the loss of valuable compressed air, increasing the overall efficiency of the compressor by not having to compress the entrained water removed during the intercooling process. This water particle removal process also reduces impeller erosion resulting in maintain long-term compressor performance. The cooled air, with reduced moisture, then passes through the next stage of compression, where the intercooling process is repeated.

Intercooler Maintenance

Keeping intercoolers clean is a vital component of scheduled preventative maintenance for your multi-stage compressor. Our intercooler bundles are easy to inspect and clean, as the entire shell is removable from the unit. Regular inspection of these components can reduce the amount of fouling in the compressor. Fouling, or the buildup of foreign materials within the intercooler, can cause corrosion and varnish of the compressor parts.

Operating with dirty intercoolers increases the risk of higher air temperatures and reduces air density during compression. This can result in reduced turndown and cause pressure to rise to surge— negatively affecting both efficiency and capacity.

FS-Elliott offers four different materials for intercooler tubing. Each material offers different levels of resiliency, heat transferability, and cost-effectiveness as shown in Table 1. Additionally, more important maintenance information is detailed on our Aftermarket Solutions- Intercooler Maintenance handout.

Table 1: Intercooler Tubing Materials
Intercooler Tubing Material	Material Properties
Copper	Best heat transfer Least resilient
Cu-Ni	More resilient Good heat transfer More expensive
Admiralty	Very resilient Very expensive Good heat transfer
Stainless Steel	Very resilient Relatively inexpensive Reduced heat transfer