FAQ: Desiccant Air Dryer Sizing

Properly sizing a desiccant air dryer may seem simple.  Just line up the maximum output of the compressor to the air dryer inlet capacity, and done!  Right? Wrong.  Done this way, you’ll end up with a dryer that is oversized and unnecessary. Properly sizing a desiccant air dryer is anything but obvious.  Keep reading to learn how to get it right.

Desiccant air dryers are designed for and needed to remove any water vapor that is found in compressed air.  These dryers work without a heater and function to -40 degrees Fahrenheit, or less.  Compared with other dryers, desiccant air dryers cost less and are as effective if sized correctly.

How to Size Your Desiccant Dryer

If you a reciprocating air compressor, especially one that is air cooled, you have a machine that is cooling the air and dissipating heat as it goes. These compressors are created to work a duty cycle betweenParker-Airtek-TW-Dessicant-Dryer 50-75% max. Let’s look at an example.  For a compressor producing 20CFM, the duty cycle hits 65%.  To size the desiccant air dryer to match this compressor, we need to calculate 65% of the total CFM, in this case, 20. The max output is no more than 13 CFM or 65% of the total CFM of 20.  The desiccant air dryer only needs to work at 13 CFM to fit the compressor and match the total dry air needed.

Why It Matters!

Many compressors are too big for their daily use, having been sized incorrectly, to begin with.  This doesn’t matter, as long as you size the desiccant air dryer to work with the compressor as you use it.  Buying a desiccant dryer that is too large for your purposes will cause it to break down much quicker than normal. These dryers are built to work day after day over long periods of time, and will keep up with the demands of your tasks as long as they are properly sized.

When sizing the desiccant air dryer you need to fit your compressor and keep up with your application needs; it’s important to get the right fit.  A dryer that is too large will cause harmful wear and tear long before normal, eliminating the cost effectiveness of this air dryer choice.  If the example does not clarify the sizing process for you, make sure to talk to a knowledgeable representative before you buy!