A cover apparatus for controlling airflow in a computing system. The cover apparatus includes a cover bracket configured to attach to the computing system in alignment with an opening of a module within the computing system. The cover bracket defines an aperture through which one or more components can be inserted into and removed from the module. The cover apparatus includes a cover door attached to the cover bracket and configured to rotate relative to the cover bracket between an open position and a closed position. The cover door closes the first aperture of the cover bracket with the cover door in the closed position. The cover apparatus includes a catch configured to apply a force to the cover door in the closed position. The force is sufficient to maintain the cover door in the closed position but allows a user to manually open the cover door for accessing the module.