Abstract: A chassis-rack system mounts two 19″ RETMA rack chassis back-to-back in the same vertical 1U-space. Each has an independent cooling system that draws-in cold air from respective front and rear panels. Such panels are provided with a series of slots that are blocked-off in different patterns according to empirical cooling tests, done with particular complements of internal constituent components. Such intakes are typically at a left side of the panel, and air drawn in is forced to flow to the back and around to the right by two floor-to-ceiling partition walls. Such walls can define bay for a CD-ROM, floppy disk, or PCI-bus. The drawn-in air is critically sequenced first over processors, memory, then hard disk drives, and finally over a power supply. The power supply is near the front on the right, typically, and-two 33-CFM fans exhaust the heated air out the respective panels.