NetShelter Aisle Containment is an intelligent thermal containment solution designed to increase cooling system efficiency while protecting critical IT equipment and personnel. The Active Flow Control (AFC) available in NetShelter Aisle Containment provides the intelligence to communicate to the cooling system in order to right size the cooling airflow to match the load of the IT equipment providing a reduction in fan energy over conventional cooling systems. The NetShelter Aisle Containment system adapts to varying rack heights, aisle widths, and rack depths to support either hot or cold aisle containment. The Air Return System of the NetShelter Aisle Containment provides a centralized hot air return path for room based CRAC/CRAH units or external air handling systems. The optional UL723s listed Fire Safe System uses temperature sensors to drop ceiling panels in the event of a fire. The Fire Safe System can also be used in conjunction with a field supplied smoke detector to activate in the event smoke is detected with the aisle. NetShelter Aisle Containment provides a safe and efficient environment for IT equipment and personnel incorporating additional features for high efficiency LED lighting with motion detection. NetShelter Aisle Containment can be deployed in zones or modules to gain the benefit at either the rack or row level.