It depends. A desiccant dryer provides more efficient water removal, but it's also more expensive initially and most require about 15% of the rated inlet capacity (SCFM) for purging, so you lose compressed air.
Therefore, the "best" type of dryer in many cases is a refrigerated dryer due to its lower initial and operating cost.
Many newer compressed air systems may use a combination of dryers. A refrigerated dryer sized for the air compressor will remove 95% of the water and provide adequate dry air for most plant applications. Additional desiccant or membrane dryers sized for the specific application (i.e. dust collector exposed freezing temperature; CNC plastic molding equipment; food processing application, etc.) can be installed downstream of the refrigerated dryer and prior to where the critical dry air is required.
