Compressed air dryers that use a refrigeration technique to extract moisture from compressed air are known as refrigerant air dryers. They are made to ensure air quality and shield equipment from damage by eliminating water vapor, which is a constant in compressed air.
The process of using a refrigerant air dryer involves quickly cooling compressed air in a refrigeration unit to a low temperature, usually about 3°C (37.4°F). Water vapor in the air condenses into pure water at this temperature, which gathers in a water trap and is supplied into discharge lines. For applications requiring compressed air dried to a low dew point, this procedure is essential.

There are two types of refrigerant air dryers: variable speed drive (VSD) and non-cycling. While VSD dryers may modify their energy usage to match air demand, non-cycling dryers run at a constant speed. This results in significant energy and operating cost reductions.
Refrigerant air dryers are extensively employed in a variety of sectors, including as manufacturing, healthcare, and food processing, where machinery and equipment are powered by compressed air. They are a crucial part of the air system because they guarantee that the compressed air is dry and free of moisture, which can deteriorate the equipment and lower the quality of the air.