Dryers, also called air dryers, are devices that remove moisture from compressed air and blow out dried air. Moisture in compressed air can have a negative effect on machine cylinders, valves, solenoid valves or other parts, which may result in failure. Water sprayed from air blow guns or moisture mixed into paint may also cause problems. As such, a dryer is usually installed in an air compressor as standard. The refrigerating system cools the air, like an air conditioner or refrigerator, and condenses or discharges moisture to dry the air. In an adsorption type, the moisture in the air is sucked out using a desiccant such as silica gel or molecular sieves. The membrane removes moisture by feeding the air through hollow fibers made from a polymer film that is easy for moisture to pass through but difficult for air to pass through.