There are four major categories of compressed air dryers, each with their own unique strengths and weaknesses.

Refrigerated Air Compressor Dryers

Refrigerated air compressor dryers work by cooling the air to condense water vapor. Generally, they will produce dew points ranging from 35-40° F, and will be unable to achieve dew points below freezing. With less need for maintenance as well as lower operating costs, this is one of the more affordable 30hp compressed air dryer options.

Regenerative Desiccant Air Compressor Dryers

Regenerative desiccant air compressor dryers utilize desiccant materials such as silica gel to remove water vapor. These systems will most frequently alternate air flow between two towers, giving the desiccant media time to dry after it has been saturated. The key feature that differentiates regenerative desiccant dryers is the fact that they can produce dew points as low as -100° F, drastically lower than other options.

Deliquescent Air Compressor Dryers

This system makes use of chemical media that absorb other media. Unlike desiccant dryers, the material within deliquescent dryers cannot be dried once it is saturated—it must be replaced. As there is no need for purge air in these systems, they are highly affordable and can provide energy savings of up to 20%. The typical deliquescent dryer requires no power to operate.

Membrane Air Compressor Dryers

Membrane air compressor dryers are composed of specialized membrane micro-tubes. As compressed air travels through the tubes, water vapor will diffuse through the permeable membrane. These systems can bring dew points down to -40° F. They are very quiet and have no moving parts. The membrane dryer does use purge air to dry the membrane, similar to a regenerative so expect a reduction of available downstream air of up to 15%.

Applications are typically limited to 120 CFM or less, but like the deliquescent dryer no power is needed to operate it.