Abstract: A platform for holding a plurality of modules or printed circuit boards wherein the platform or chassis contains shutters placed over airflow openings in the platform. The shutters are normally closed and are opened be the act of inserting a module into the platform. The shutters are in the closed position in all slots not occupied by a module and are in the open state in all slots populated by a module. The shutters open as the module is inserted and close when the module is removed. The closed shutters prevent airflow from passing through the unpopulated slots and empty space within the platform, thus forcing the airflow to pass through the space in which the modules are present. The platform also comprises a means of controlling the number of fans that are operational in accordance with the number of modules installed in the platform. The fans closest to the modules inserted into the platform are operational while fans close to unpopulated slots are turned off.

Abstract: A platform for holding a plurality of modules or printed circuit boards wherein the platform or chassis contains shutters placed over airflow openings in the platform. The shutters are normally closed and are opened by the act of inserting a module into the platform. The shutters are in the closed position in all slots not occupied by a module and are in the open state in all slots populated by a module. The shutters open as the module is inserted and close when the module is removed. The closed shutters prevent airflow from passing through the unpopulated slots and empty space within the platform, thus forcing the airflow to pass through the space in which the modules are present. The platform also comprises a means of controlling the number of fans that are operational in accordance with the number of modules installed in the platform. The fans closest to the modules inserted into the platform are operational while fans close to unpopulated slots are turned off.