Warm weather increases compressed air moisture

Posted: June 9, 2009 in Air Compressors, Compressor Maintenance, Industrial Equipment


Ask a Question:

There is more moisture in my compressed air in the warm weather. Can this water or moisture be damaging my compressed air system?


Absolutely! Water corrodes pipes, valves, machinery controls. None of this is good. When controls malfunction, production can stop or product can be impaired and all this costs you time and money.
In summer’s warmer temperatures moisture and condensation occurs more frequently.

Why?  The reason is warm air can hold more moisture than cooler air. Therefore when the temperatures rise in the heat of spring and summer, then the amount of moisture in the air around you and your compressed air also rises. In more humid regions of the country, compressed air systems can be challenged by this moisture increase.

Many processes need to remove moisture from their compressed air. One such example is spray painting. Condensed water droplets in a painting process can ruin the end result. Other examples are pharmaceutical production and medical applications that need clean, dry compressed air.

Ask a Question:

How does water or moisture get into my compressed air?


Through your Compressor inlet.

Water vapor (humidity-moisture) enters the air system through the air compressor inlet air filter.
The air compressor sucks in approximately 7 cubic feet of atmospheric air at 0 psig, and that volume of air is compressed into 1 cubic feet of air at 100 psig.
The water vapor (humidity-moisture) that was in the seven (7) cubic feet of atmospheric air is now compressed into ONE (1) cubic feet of compressed air.

There are 3 forms of water in compressed air:

1. Liquid water
2. Aerosol (mist)
3. Vapor (gas)

Water in Aerosol or Vapor form is more difficult to remove and requires the use of a Compressed Air Dryer.

Refrigerated Air Dryers can be the solution to water and moisture in your Compressed Air System


The refrigerated air dryer cools the incoming compressed air first in an air-to-air heat exchanger where the outgoing cool dry air pre-cools the hot incoming air and condenses some moisture out.

Then the incoming air enters an air-to-refrigerant heat exchanger where the air is cooled to 38º F by the liquid refrigerant. This process causes the moisture to condense into liquid water and it is drained away.

The out going air then enters the air-to-air heat exchanger and is warmed up to keep the outside of pipes from sweating.

The refrigeration compressor pumps hot hi-pressure gas refrigerant (Freon) into the condenser which transfers the heat from the refrigerant gas to the ambient air as the gas condenses into a liquid.

The liquid refrigerant (Freon) is then metered to a cold low pressure where it enters the air-to-refrigerant heat exchanger and the heat from the hot compressed air is adsorbed into the cold refrigerant (Freon). The refrigeration compressor then sucks low pressure hot gas refrigerant (Freon) into the refrigeration compressor and the cycle starts over again.

Tommy McGuire
Owner of McGuire Air Compressors, Inc.
“Real People with Real Air Compressor Experience”


Email: compressors@mcguire.biz

Learn more about Refrigerated Air Dryers

  1. Some nice information here Tom. Thanks.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s