Membrane dryers remove water vapor through a fiber layer that draws the water vapor out into the atmosphere while moving the dry air downstream. They protect downstream components from damage caused by traces of moisture in the air supply. Because a small amount of compressed air is diverted to draw water vapor out, there is a slight drop in the total air flow (cfm) available to downstream tools. Membrane dryers can reach lower dew points than refrigerated dryers and do not need a power source. They are compact, lightweight and suitable for use in electronic cabinets and environmental chambers.