Air Compressor Works

The Dryer Light Is On, Why Do I Have Wet Air?

May 17, 2019
wet air

We all assume that if the power light is on the dryer must be working.

When we take a look at the refrigerated dryer in our compressor room we assume that everything is okay. Then later that day or the next morning someone tells us that water is showing up in the production equipment or contaminating product.

So now what? Well, the dryer may be working and there are 6 simple checks that you can do to see what is really going on in your system.

Step 1

Do what I call the “cough test,” which is reaching to the cabinet opening in your dryer to find the condensate separator or the outlet line. It should 40/45 ° F which feels fairly cold to the touch. If it isn’t cold, the dryer has a problem. Action Item: have the refrigeration circuit checked and make sure the condenser is clean.

Step 2

Believe it or not one of the most common issues is that the bypass valves are either left partially open or do not close completely. If they seem to be closed, that is good, but you might want to check further. Action Item: check by closing all three valves and seeing if the air pressure after the last 12 goes to zero. If it doesn’t, you need to replace the valve.

Step 3

Inlet air temperatures to the dryer should be no more than 100° F. If you can put your hand on the dryer inlet pipe and it doesn’t feel hot to you, that is good. If it feels hot to the touch, that may be the problem. Action Item: check the air cooled, or water cooled, aftercooler on the compressor to make sure it is clean and the air temperature is no more than 15° F above room temperature . It may have to remove and clean thoroughly.

Step 4

As mentioned above, your compressor room really should not be any hotter than the outside temperature, If it’s more than 10° F above the outside temperature, you could have a problem for all of the equipment in the room. Dryers are designed to run at 100° F ambient. Action Item: get your HVAC or compressor vendor to review your compressor room ventilation.

Step 5

Check to see if there is any condensate coming out of the dryer drain trap. If a sizable amount is not accumulating from the trap it means the dryer may be working but you’re not removing the water. Action Item: isolate the drain trap to clean/repair or replace it. REPLACE ONLY WITH A DEMAND TYPE TRAP. We recommend a zero loss drain trap when possible to prevent the waste of you valuable compressed air.

Step 6

Check the low point in your piping system beyond the dryer to see if there is any condensate that can be drained out. If you find water go back to the other steps but in the meantime put a drain on this low point to help eliminate moisture in the system.

If you’ve taken these 6 steps and everything proves out, then it’s time to call your compressed air vendor to find out what’s going on. If you can’t get the results you need pick up the phone and call the Air Compressor Works team at (800) 345-4364 to get your system dried out.

Contact Us

By providing your mobile phone number, you agree to receive text messages from Air Compressor Works, Inc. Message and data rates may apply. Message frequency varies. Reply HELP for help and STOP to cancel. Please view our Privacy Policy.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Contact Us

Palm beach:

1956 W 9th St
Riviera Beach, FL 33404
Monday – Friday 7:30 AM - 4:30 PM
Map and Directions


7292 NW 25th St
Doral, FL 33122
Monday – Friday 7:30 AM - 4:30 PM
Map and Directions

Phone Number:

(800) 345-4364

Areas We Serve

  • Miami
  • Fort Lauderdale
  • Hollywood
  • Boca Raton
  • Stuart
  • Vero Beach
  • Delray Beach
  • West Palm Beach
  • Homestead
  • Key West
  • Fort Pierce
Air Compressor Works logo