HP Onboard Administrator - Manual (Page 266)

Configuring the HP BladeSystem c7000 enclosure and enclosure devices 266
Ten Fan Rule
All fan bays are used to support a maximum of 16 devices in the device bays.
c3000 Enclosure fan location rules
The HP BladeSystem c3000 enclosure ships with four HP Active Cool fans and supports up to six fans. You
must install fans in even-numbered groups based on the total number of server blades installed in the
enclosure and install fan blanks in unused fan bays.
Four Fan Rule
Fan bays 2, 4, 5, and 6 are used to support a maximum of four devices located in device bays 1, 2, 5 or 6.
Six Fan Rule
All fan bays are used to support a maximum of eight devices in the device bays.