Equipment Orientation; Electrostatic Discharge (Esd): Source Of Greatest Failure Rate Without Detection; Cellular Telephone And Wireless Usage; Comprehensive Discussion - HP 9000 rp3410 Manual

Also be aware that the racking cabinets are integral to the proper environmental support for
mounted equipment. See the following additional items:
• Cabinet blanking panels must be used in non-populated U-space levels to prevent
unpredictable air mixing. This can lead to No Trouble Found (NTF) diagnosis.
• Use the highest percentage cabinet perforation possible to allow the proper ventilation in
the cabinet.
• Cabinet doors must be used in the front and the rear. They must be grounded to the cabinet
using existing ground lugs and ground straps or cables.

Equipment Orientation

Data center equipment orientation, or heat load, must encourage sufficient airflow. If exhausted
heat must move over or around a cabinet, air vortexes might be created, resulting in airflow
inefficiency throughout the data center and inside the equipment. Equipment might develop
internal hot spots, resulting in sluggish performance or even system failure.
Rather than designing a layout to maximize a planning grid worksheet whitespace, create "hot"
and "cold" aisles. In a hot aisle, equipment is oriented so that exhaust vents face other exhaust
vents. In a cold aisle, intake vents face other intake vents. Place vent tiles in the cold aisles, with
few to no vent tiles in the hot aisle. Position equipment in parallel to encourage the lowest air
resistance and turbulence. Consider the following when determining equipment orientation:
• Orient equipment in parallel to airflow.
• Place cabling in such a way as to aid airflow rather than impede it.
• Arrange equipment to form hot and cold aisles.
• Use vent tiles to control airflow in heat load areas.
• Place vent tiles in cold aisles.
• Place higher heat load devices at floor level.

Electrostatic Discharge (ESD): Source of Greatest Failure Rate Without Detection

Computer equipment is increasing in processor and memory density even as size continues to
decrease. These smaller, more densely packed pieces of equipment are at greater risk to damage
from electrostatic discharge. ESD created by the human body can be any voltage from zero, some
voltages beginning at twenty five volts (25V). ESD that is felt by the human body can be 3,000
volts.
Contemporary electronic technology can be damaged or upset by voltages far lower than the
human experience would indicate.
HP recommends building this consideration into your designs for floor coverings, humidity
control, airflow, dust control, and personnel traffic. Consider the following precautions to prevent
or minimize ESD:
• Use antistatic flooring.
• Maintain humidity at 40%–55% relative humidity.
• Follow airflow recommendations.
• If raised flooring is present, use a 2-foot by 2-foot (61-cm by 61-cm) grounding grid.
• Always use appropriately sized AC power ground wires.
• Limit personnel traffic to two floor tiles away from equipment.

Cellular Telephone and Wireless Usage

HP recommends not using cell phones within a data center, especially within 9.8 feet (3 m) of
any high-availability equipment.

Comprehensive Discussion

The following environmental elements can affect a product installation:
18 General Site Preparation Guidelines