A compressed air dryer removes moisture (water vapor) from compressed air to prevent corrosion, contamination, and damage to equipment, tools, and products. This is achieved through methods like refrigeration, which cools the air to condense moisture, or desiccant drying, which uses a material to absorb the water vapor. By ensuring the air is clean and dry, a compressed air dryer maintains system efficiency, reliability, and the longevity of the system and the equipment it powers.