An enclosure is provided for housing electronic equipment that accommodates the different cooling and ventilating requirements of different types of equipment. The enclosure is constructed and arranged to support cooling airflow in a front-to-back configuration through the enclosure and in a side-to-side configuration from one side to an opposite side of the enclosure. The enclosure can thereby provide within a single enclosure means cooling air for components using front-to-back airflow for cooling, such as information technology (IT) equipment, and for components using side-to-side airflow, such as certain types of telecommunications equipment. The enclosure can thereby support a mix of IT and telecommunications equipment, providing flexibility and adaptability in network room and data center configuration. The enclosure is further configured to separate intake air used by equipment for cooling from exhaust air vented by equipment into its interior during operation. As a result, the enclosure promotes sufficient equipment cooling and prevents/minimizes equipment overheating.