Compressed Air Equipment

8 Key Considerations for Compressed Air Equipment in Cold Temperatures

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Winter is upon us, and what better way to prepare for the cold weather? By learning how cold ambient temperatures affect your compressed air equipment and system.

Contents:
Cold ambient conditions and air compressors
Cold ambient conditions and air dryers
Cold ambient conditions with compressed air accessories and other components
Tips for getting up and going in cold weather (no, not you – your compressed air system)

Air Compressors

  • Air compressor oil tends to become thicker when ambient temperatures are cold, thus reducing its lubrication capabilities. Thicker oil also increases the power needed to turn the pump thus increasing motor amp draw and strain on the whole drive train. This can reduce the lifetime of your machine’s motor.
  • Control lines do not operate on the dry side of your compressed air system. Because of this moisture, cold ambient temperatures can lead to freezing up of these lines within the compressor which can quickly alter the operation of the machine.
  • Many rotary screw compressors, include low ambient alarms, preventing them from starting when cold.
    Note: if it is already running, it will most likely continue to run because the compressor will generate enough of its own heat to keep it above freezing temperatures.
  • Tip: If your rotary screw air compressor will not start, there is a high likelihood that the ambient temperatures around your air compressor are below +40°F. Many rotary screw air compressors are equipped with a low ambient air temperature limit switch (fault), which does not allow the machine to start below this temperature. See the section below on Tips for getting up and going in cold weather.

Air Dryers

  • In cold ambient conditions, refrigerated dryers actually tend to operate too efficiently, meaning that the moisture it is trying to separate out will be cooled to a point where it will actually freeze within the machine. This could not only cause internal blockage, but because of the water expanding as it freezes, it will probably also crack the heat exchanger.
  • Also, the drain valve on a refrigerated air dryer may freeze open or shut. This may not create a blockage of the air flowing through the dryer, but it will block the condensate from draining. Even though the dryer is chilling the air, the moisture cannot escape, and the dryer becomes ineffective.
  • With desiccant dryers, wet inlet air tends to start freezing up inside the piping causing a blockage.
  • Also with desiccant dryers, the discharge air purge mufflers can freeze up, restricting or stopping the purge air flow thus decreasing the drying capacity of the dryer.

Compressed air accessories and other components

  • As with compressors and dryers, anytime condensate freezes, there is opportunity for air and/or water blockage in all accessories (such as drain valves, filters, and regulators) and tanks. Although thawing of this ice can quickly free up the blockage, freezing water can expand to a point where it will cause permanent damage to the component. Examples: cracked drain valves, fractured filter bowls, and compromised tank pressure ratings.