Variodry membrane dryers are suitable for compressed air system applications. They are installed in-line and require no electrical connections. Air flows through a bundle of hollow fibers with semi-permeable membranes contained within the dryer. Moisture then diffuses across the membrane and is carried away by a portion of air flow that is swept back across the outside of the fiber bundle. According to the manufacturer, pressure dewpoints ranging from 0 to 35 degrees Celsius PDP at moderate flow rates.