Abstract: A dehumidifying system uses a membrane cartridge to filter water vapor from air or other gas introduced into the membrane cartridge via a main pump or compressor. Dehumidified gas from the membrane cartridge is then delivered into a system which requires dry gas. The dehumidifying system further includes valve arrangements or additional compressors which provide gas flow through the membrane cartridge when the main compressor is inactive. Therefore, the membrane cartridge receives a substantially continuous flow of gas which maintains the optimal efficiency of the membrane cartridge. In addition to the arrangements which provide this continuous gas flow, a heating coil wrapped around the membrane cartridge raises the temperature of the fiber membranes within the cartridge. The heated fiber membranes are less susceptible to retain moisture which decreases the efficiency of the membrane cartridge.