A data center may be defined as a location, for instance, a room, that houses computer systems arranged in a number of racks. Standard racks may be configured to house a number of computer systems, for instance, about forty (40) to eighty (80) systems. The computer systems typically include a number of components, such as, one or more of printed circuit boards (PCBs), mass storage devices, power supplies, processors, micro-controllers, semi-conductor devices, and the like, that may dissipate relatively significant amounts of heat during the operation of the respective components. For example, a typical computer system comprising multiple microprocessors may dissipate approximately 250 W of power. Thus, a rack containing forty (40) computer systems of this type dissipates approximately 10 KW of power.
Computer rooms are known to be built with raised floors. The under floor volume is pressurized with a cooling fluid, often chilled air. Where cooling is needed, the cooling fluid blows upwards through vented floor tiles. These vented floor tiles are often mechanically constructed devices, which contain fixed venting (covering a known percentage of their surface area) or are designed with adjustable louvers or sliding apertures to allow more or less of the cooling fluid to flow through the tile. The cooling fluid flows upwards through the vented floor tiles towards the hot computer systems and is circulated throughout the computer systems, causing a cooling effect.
The need for the cooling fluid varies in the short term as load gets passed around the room and in the long term as more computer systems are added to the room or racks are vacated. As such, some types of vented floor tiles are known to incorporate servo mechanisms to adjust louvers contained therein, under computer control, to the desired angle in order to vary the volume flow rate of the cooling fluid. These types of vented floor tiles are often controlled based upon data collected by sensing grids, which typically determine the required volume flow rate of the cooling fluid by monitoring the temperature of computer systems within the room. However, current sensing grids require extensive cabling within the room and underneath the floor. Additionally, the sensing grids are often extremely sensitive because of the relatively high potential for the extensive cabling to fail.