Providing clean air for PEM fuel cells is crucial to prevent premature degradation of the stack caused by harmful gases poisoning platinum catalysts. For this purpose, special activated carbon mixtures are used that reliably adsorb target gases such as NOx, NH3 and SO2. Basic investigations in research projects create the basis for the application-oriented design of the filter elements. To prevent flooding of components in the cathode air path including the stack, water separators are used at various positions in the overall system. The components in the air path are designed according to the temperature and pressure requirements prevailing in the application, with sensors and actuators enabling system control and management. Applying optimized silencers, disturbing noises, e.g. from the compressor, can be reduced or even eliminated. Central system components such as humidifiers and heat exchangers positioned in charge air lines can be efficiently integrated into the overall system. Additional water separators to protect the turbine and prevent the discharge of liquid water from the tailpipe in the cathode exhaust path, as well as a reservoir, are advantageously integrated into the overall system using plastics technology. This holistic approach enables acoustically optimized and compact cathode air paths for PEM fuel cells.