HP BladeSystem Enclosure technologies manual HP PARSEC architecture

HP PARSEC architecture

HP Parallel Redundant Scalable Enclosure Cooling (PARSEC) architecture is a hybrid model for cooling that combines the best of local and centralized cooling in a single system to ensure optimum airflow and cooling for all servers. Density, once a barrier to cooling, is turned into an advantage with HP Thermal Logic technologies like HP PARSEC architecture and HP Active Cool fans. With these innovations, server blades get more cooling airflow where it is needed most and use less power than traditional rack servers.

To optimize thermal design, HP developed a relatively airtight center air plenum, or air chamber. For example, all device bays include a shutoff door that is normally closed to prevent air leakage through that device bay. When a server blade is inserted, it seals into the center air plenum docking collar, and the server shut-off door opens to allow airflow across that server blade. Similarly, the fan seals into the center air plenum docking collar. Each fan bay includes louvers that automatically open when a fan is installed. If a fan is not installed or is not functional, the pressure distribution around the fan changes. This pressure change causes the louvers to close, ensuring that cooling air is not diverted through the non-operating fan.

The enclosure and the components within it optimize the cooling capacity through unique mechanical designs. Airflow through the enclosure is managed to ensure that every device gets cool air, that no device sits in the hot exhaust air of another device, and that air only goes where it is needed for cooling. Fresh air is pulled into the interconnect bays through a slot in the front of the enclosure. Ducts move the air from the front to the rear of the enclosure, where it is then pulled into the interconnects and the central plenum. The air is then exhausted out the rear of the system (Figure 4).

Figure 4. HP BladeSystem c3000 self-sealing enclosure

Base BladeSystem c3000 Enclosures ship with four installed fans that support up to four half-height devices in device bays 1, 2, 5, and 6, or two full-height server blades in device bays 1 and 2. Adding two additional fans to the enclosure allows population of eight half-height devices or four full- height server blades.

In a four-fan configuration, the Onboard Administrator prevents server and storage blades installed in device bays 3, 4, 7, and 8 from powering on until two additional fans are added into fan bays 1 and 3. To populate blade devices in all eight device bays, it is necessary to populate c3000 Enclosures with six Active Cool fans. Figure 5 shows enclosure fan bay and device bay population guidelines. See Appendix B for more detailed fan and device bay population guidelines.

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