When it comes to Compressed Air Dryers there are two types that make up the majority of the units in the field: Refrigerated & Desiccant. Each have their own advantages and capabilities, and the unit you may need will depend on your exact circumstances.
Refrigerated Air Dryer – Refrigerated Air Dryers work by dropping the temperate of the air to approximately 37 degrees Fahrenheit. This causes the moisture in the air to condensate. This condensate, along with airborne dirt and oil, will then travel to the separator, where the automatic drain removes it from the air stream.
Application – Manufacturing that does not require a dew point below 38 degrees Fahrenheit.
Pros – Small footprint, and have a lower purchase, operating and maintenance cost.
Cons – Unable to achieve a dew point as low as what Desiccant is capable of.
Desiccant Air Dryers – Desiccant Air Dryers work by adsorbing (different from absorbing) moisture from the air stream and onto a desiccant material. This desiccant material, usually in the form of beads, then has the moisture removed through a regenerative process, then reused.
Application – Metal finishing and other ultra-dry air applications.
Pros – Able to achieve a dew point as low as -40 to -100 degrees Fahrenheit.
Cons – Higher purchase, operating and maintenance cost.