IBM DS4800 - Heat Output, Airflow, and Cooling

on a metal table. Take additional care when handling devices during cold weather
because heating reduces indoor humidity and increases static electricity.
Heat output, airflow, and cooling
The maximum heat output of the DS4800 is 235 watts (803.7 BTU/hr). Each
DS4800 rack-mounted unit requires an airflow of 2.5 m
3
(87 ft.
3
) per minute. The
input air temperature to all rack cabinets should be in the range 10° C - 35° C (50°
F - 95° F). The recommended operating temperature is 22° C (72° F).
When rack cabinets that contain many DS4800s are to be installed together, the
following requirements must be met to ensure that the DS4800s are adequately
cooled:
v Air enters at the front of the rack cabinet and leaves at the back. To prevent the
air that is leaving the rack cabinet from entering the intake of another piece of
equipment, you must position the rack cabinets in alternate rows, back-to-back
and front-to-front. This arrangement is known as “cold aisle/hot aisle” and is
shown in Figure 11 on page 29.
v Where rack cabinets are in rows, each rack cabinet must touch the rack cabinet
that is next to it. This reduces the amount of hot air that can flow around from the
back of the rack into the intakes of the storage subsystems that are in that rack
cabinet. You should use Suite Attach Kits to completely seal any gaps that
remain between the rack cabinets. For details about Suite Attach Kits, contact
your marketing representative.
v Where rack cabinets are in rows front-to-front or back-to-back, a gap of at least
1220 mm (48 in.) must separate the rows across the cold aisle.
v To ensure correct airflow in each rack cabinet, the rack filler plates must be
installed in unused positions. Also, all the gaps in the front of the rack cabinets
must be sealed, including the gaps between the storage subsystems.
28 IBM System Storage DS4800 Storage Subsystem: Installation, User’s, and Maintenance Guide