HP StorageWorks X9720 Network Storage System Controller User Guide (496784-002, December 2009)

Space and airflow requirements
To allow for servicing and adequate airflow, observe the following space and airflow requirements
when deciding where to install a rack:
• Leave minimum clearance of 63.5 cm (25 in) in front of the rack.
• Leave minimum clearance of 76.2 cm (30 in) behind the rack.
• Leave minimum clearance of 121.9 cm (48 in) from the back of the rack to the back of another
rack or row of racks.
HP enclosures draw in cool air through the front door and expel warm air through the rear door.
Therefore, the front and rear rack doors must be adequately ventilated to allow ambient room air to
enter the cabinet, and the rear door must be adequately ventilated to allow the warm air to escape
from the cabinet.
CAUTION:
To prevent improper cooling and damage to the equipment, do not block the ventilation openings.
CAUTION:
When a vertical space in the rack is not filled by a server or rack component, the gaps between the
components cause changes in airflow through the rack and across the servers. Always use blanking
panels to fill empty vertical spaces in the rack. This arrangement ensures proper airflow. Using a rack
without blanking panels results in improper cooling that can lead to thermal damage.
The 9000 and 10000 Series racks provide proper server cooling from flow-through perforations in
the front and rear doors that provide 64 percent open area for ventilation.
CAUTION:
When using a Compaq-branded 7000 Series rack, you must install the high airflow rack door insert
[P/N 327281-B21 (42U) or P/N 157847-B21 (22U)] to provide proper front-to-back airflow and
cooling.
CAUTION:
If a third-party rack is used, observe the following additional requirements to ensure adequate airflow
and to prevent damage to the equipment:
• Front and rear doors—If the 42U rack includes closing front and rear doors, you must allow 5,350
sq cm (830 sq in) of holes evenly distributed from top to bottom to permit adequate airflow
(equivalent to the required 64 percent open area for ventilation).
• Side—The clearance between the installed rack component and the side panels of the rack must
be a minimum of 7 cm (2.75 in).
Rack and environmental requirements34