Loudness; Air Flow Requirements; Table 5.20 Internal Air Flow - Hitachi 9900 User And Reference Manual

5.7.3

Loudness

The acoustic emission values [loudness in dB(A)] for a maximum 9960 subsystem
configuration (one DKC, six DKUs) are:
Front/rear = 64 dB(A)
Both sides = 57 dB(A)
Note: These values were extrapolated from the values for one DKC and one DKU.
5.7.4

Air Flow Requirements

The 9900 subsystem is air cooled. Air must enter the subsystem through the air flow intakes
at the sides and bottoms of the frames and must be exhausted out of the tops and sides, so
it is very important that the air intakes and outlets remain clear. Hitachi Data Systems
recommends that under-floor air cooling has a positive pressure and meets the specifications
listed in Table 5.20. For subsystems located at elevations from 3,000 to 7,000 feet (900 to
2,100 meters) above sea level, decrease the maximum air temperature by two degrees for
each 1,000 feet (300 meters) above 3,000 feet (900 meters).
Table 5.20 Internal Air Flow
Subsystem Type
9960
9910
Subsystem Configuration
Control Frame with 8 GB Cache Memory, two
8-port Fibre Adapter and additional Disk Adapter
Control Frame with all options
Array Frame, fully configured
Subsystem fully configured
Hitachi Lightning 9900™ User and Reference Guide
Air Flow (ft /min) Air Flow (m
3
636
636
424
530
/min)
3
18
18
12
15
113