Abstract: A barrier element for forming a component of a floor covering of a floor in a data center includes a substantially laminar part, the laminar part having a cross member attached to one surface. The cross member mounts a plurality of filaments which can form a layer impervious to air flow.

Abstract: A rack system for mounting at least one data processing unit includes a shelf operable for moving from a position internally of the rack system to a position externally of the rack system. The shelf has an aperture and a fluid mover for moving fluid through the aperture in the shelf when the shelf is located in its external position.

Abstract: An adjustable blocking arrangement for electronic hardware or computer racks, for preventing the undesired leakage of air through rack spaces not filled with hardware. An airflow control device is provided comprising a flexible web and a magazine adapted to receive the part of the flexible web that is not deployed. The device is adapted such that a length of the web may be deployed to sealingly block a space in the rack that is not filled with hardware modules, to prevent the flow of air through the space. The device may comprising a detection system adapted to detect the space in the rack that is not filled with hardware modules, and a processing system adapted to receive a signal from the detection system, and as a function of the signal to automatically deploy or retract the flexible web so as to sealingly block the space.