Rack enclosure cooling systems and related methods

A system includes an enclosure with a device space having a layer of active devices arranged into rows and adjacent cooling channels and an inlet partition having apertures aligned to the cooling channels defining a supply plenum. In a method of use, cooling fluid, such as air, is transferred from the supply plenum to the cooling channels to concurrently cool the layer of active devices and may provide substantially the same temperature and flow of cooling fluid to each row of active devices. Active devices may include storage devices. The supply plenum may include elongate ducts to encourage uniform cooling along a row. The supply plenum may also include a duct partition or more than one supply plenum to encourage uniform cooling among the rows. One or more fans may provide pressurized cooling fluid in the supply plenum space.