A cooling apparatus for a container-based data center includes an air handling housing, at least one movable louver, a filter and a fan. The housing is configured for suspending from a ceiling of the container and comprises at least one heat exchanger. The louver is movable to direct air flow along different paths within the housing according to a selected operating mode. The fan is positioned in the housing and controllable according to the selected operating mode. The heat exchanger is configured in a self-contained water chilling circuit positioned within the container for use in a closed loop mode. The apparatus is convertible for use in an economizer mode that draws outside air into the container. An optional auxiliary heat exchanger element has a cold side heat exchange portion positioned outside the container and a connection through the ceiling to a hot side heat exchange portion positioned within the housing.