User Service Guide, Fifth Edition - HP Integrity rx8640 SEU

ventilation and to help reduce the localized airflow dead spots that typically occur at the faceplate
tail of each PCI card.
Standby Cooling
Several components within the chassis consume significant amounts of power while the system
is in standby mode. The fans within the power supply operate at full speed during standby.
Typical Power Dissipation and Cooling
Table 2-7 provides calculations for configurations exactly as described in the table.
Table 2-7 Typical SEU Power Dissipation and Cooling
Typical CoolingTypical
Power
Bulk Power
Supplies
Core I/OHard Disk
Drives
DVDsPCI Cards (Maximum
25W)
BTUs/HourWattsQtyQtyQtyQtyQty
1925564224116
151644422218
134539421108
The air conditioning data in Table 2-7 is derived using the following equations:
• Watts x (0.860) = kcal/hour
• Watts x (3.414) = Btu/hour
• BTU/hour divided by 12,000 = tons of refrigeration required
NOTE: When determining power requirements, you must consider any peripheral equipment
that will be installed during initial installation or as a later update. Refer to the applicable
documentation for such devices to determine the power and air-conditioning that is required to
support these devices.
Acoustic Noise Specification
The acoustic noise specification for the SEU is 57.1 db (sound pressure level at bystander position)
when connected to the HP Integrity rx8640 server as the host system. It is appropriate for dedicated
computer room environments, not office environments. The LwA is 7.4 Bels. Care should be
taken to understand the acoustic noise specifications relative to operator positions within the
computer room or when adding servers to computer rooms with existing noise sources.
Air Flow
The SEU requires that the cabinet air intake temperature be between 68° F and 77° F (20° C and
25° C) at 150 CFM.
Figure 2-1 illustrates the location of the inlet and outlet airducts on a single cabinet. Air is drawn
into the front of the SEU and forced out the rear.
Environmental Specifications 31