Air Compressor Coolers : Intercoolers, Aftercoolers and oil coolers

Compressor air cooler
  • Cools compressor discharge air or inter-stage temperature in a multi stage compressor helping in higher compression ratio.
  • Air compressor after cooler reduce the moisture content of compressed air systems.
  • Compressed air aftercooler make sure downstream equipment is protected from excessive heat and moisture providing clean dry air. 
  • Air compressor oil cooler keeps the compressor oil cool.
  • Intercooler Reduces scheduled maintenance for compressor and compressed air after cooler ensures the same for downstream air tools connected to compressed air system by ensuring optimum operating conditions.
  • Reduces air lines, fittings corrosion in reciprocating compressors, rotary screw air compressors, Centrifugal air compressor and compressed air piping.
  • It reduces the load on downstream equipment’s like air dryer
  • Oil-Injected Rotary Screw    180-220°F 
  • Oil-Free Rotary Screw       300-350°F 
  • 2-Stage Reciprocating       250-300°F 
  • Centrifugal compressor     180-235°F 

Compressed air cooler

Air that is too hot is usually not appropriate for use in air-operated equipment because it degrades lubrication and seal materials. Moisture vapor contained in hot air can also cause rust, scale build-up, the loss of lubricant, and freezing issues, when it condenses. Atmospheric air contains water vapor, which becomes more concentrated when the air is drawn into a compressor and pressurized. Since the air after compression is extremely hot, the moisture remains in a vapor state, above the dew point temperature. Dewpoint is the temperature at which air becomes saturated when it is capable of holding 100 percent of its capacity to hold water vapor. In general, the air can hold twice as much moisture in a vapor state as it can below the dewpoint for every 20°F rise in temperature. With cooling, the dew point drops and water vapor condenses. The water vapor in the air will become droplets if the amount of moisture in the air exceeds the dewpoint. Without an aftercooler, a 200 CFM air compressor operating at 100 PSI may result in up to 45 gallons of water every day in the compressed air cooling system.


Air Cooled compressed air coolers

The hot compressed air is cooled by ambient inlet air in air cooled compressed air coolers. A motor-driven fan forces ambient air over the cooler as compressed air travels through an air-cooled cooler. It is designed with a spiral-finned tube coil or with a plate-finned coil design. Compressed air is cooled by ambient air. An air-cooled aftercooler is usually sized to bring compressed air to within 15°F to 20°F of ambient cooling air temperature, also called approach temperature. When compressed air cools, up to 75% of the water vapor condenses into a liquid, which needs to be drained. The liquid moisture and solids in compressed air are removed mechanically from the air using a moisture separator installed at the discharge of the aftercooler. Moisture and solids are collected at the bottom of the moisture separator using centrifuges and baffle plates, in some cases. Moisture should then be removed through an automatic drain.  

Water-Cooled Air Compressor Cooler

Unlike air-cooled aftercoolers, water-cooled air compressor coolers are installed in stationary compressor installations where there is access to cooling water. As a cooling medium, water has several advantages: Having no seasonal temperature fluctuations which is common for inlet air temperature, it is cost-effective and readily available, and it can approach ambient air temperatures efficiently, eliminating condensation downstream and cooling compressed air effectively for places with requirement of industrial compressed air. Temperatures in water-cooled aftercoolers range between 10°F and 15°F, which is beneficial when cooler air is needed. There are several types of water-cooled aftercoolers available. A Shell and Tube aftercooler is the most common. There are tubes fitted inside this shell that makes up the aftercooler. As compressed air passes through the tubes, water passes through the shell in the opposite direction or vice versa. Heat transfer from the compressed air to the water during this process. Water is formed within the tubes as the compressed air cools. Like an air-cooled cooler, a moisture separator and drain valve are used to remove the moisture.  

The compressor air coolers in centrifugal compressors have a massive influence on their efficiency and thus also on their operating costs. They not only affect air compressor cooling but affect the air compressor maintenance. To run a industrial air compressors economically over the long term, the compressors’ users must deploy high-quality and technically advanced air cooling systems.


Cooling water requirements vary depending upon many factors, contact us to determine the precise cooling water requirement for your specific compressor model.

Compressor coolers can be cleaned mechanically as well as by using correct chemicals. Contact us today to know more!!

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