A dissipation module has a dissipation fin module and a centrifugal fan. The centrifugal fan outputs airflow towards the dissipation fin module to remove the heat from it. The centrifugal fan includes a centrifugal impeller mounted on a motor. An outer housing houses the motor and the centrifugal impeller. Convex members or concave portions are formed on an inner wall of the housing outlet so as to reduce noise. The dissipation fin module includes a fin set closely attached to a heat source, as well as an airflow channel housing. Convex members or concave portions are also formed on an inner wall of the airflow channel for reducing noise.