Figure 7. Air Flow - Seagate ST118273FC Product Manual

Barracuda 18FC Product Manual, Rev. B 29
The drive should be oriented, or air flow directed, so that the least amount of air-flow resistance is created
while providing air flow to the electronics and HDA. Also, the shortest possible path between the air inlet and
exit should be chosen to minimize the travel length of air heated by the drive and other heat sources within the
rack, cabinet, or drawer environment.
Possible air-flow patterns are shown in Figure 7. The air-flow patterns are created by one or more fans, either
forcing or drawing air as shown in the illustrations. Other air-flow patterns are acceptable as long as the tem-
perature measurement guidelines are met.
Above unit
Under unit
Note. Air flows in the direction shown (back to front)
or in reverse direction (front to back)
Above unit
Under unit
Note. Air flows in the direction shown or
in reverse direction (side to side)
Figure 7. Air flow
To confirm that the required cooling for the electronics and HDA is provided, place the drive in its final mechan-
ical configuration, perform random write/read operations and, after the temperatures stabilize, measure the
case temperature of the components listed below. Component reference locations are shown in Figure 8. The
typical ambient air temperature associated with the list is 25 ° C and the resulting MTBF is 1,000,000 hours.
FIgure 7 shows the air flow pattern used to generate the 1,000,000 hours MTBF temperature guidelines listed
below. Local average air velocities were 235 lpm (1.2 m/s) and air temperature was 77°F (25°C) plus a 5°C
temperature rise in the test enclosure (30°C ambient local to the drive).