A system for cooling computing devices within a facility includes an air inlet that delivers cool air to a supply air space within the facility, an exhaust air damper that is configured to exhaust heated air from an exhaust air space within the facility, and computing devices that are arranged within the facility to at least partially partition the supply air space from the exhaust air space. The system also includes an air filter that is configured to filter the cool air and a mixing damper that is positioned within the interior space of the facility and that is operable to control an amount of exhaust air that is mixed with the cool air. The cool air and/or a portion of the exhaust air are used to cool the computing devices and airflow through the system is substantially driven by fans of the computing devices.