dave04a at dunfield.com
Fri Jun 17 06:01:01 CDT 2005
At 21:31 16/06/2005 -0400, you wrote:
> OK, this is a stupid question. I'm fixing up the 8800b that I got
>recently and I removed the fan to perform some work on the power supply.
>Unfortunately I didn't mark which direction the air blows. Can someone tell
>me if it blows inward or outward?
Both of my 8800s have the fan blowing out.
The general rule is:
If the fan has a filter, then it should blow in.:
By maintaining positive internal pressure, and
filtering the air that comes in, you keep dust
from entering the box.
If it does not have a filter, it should blow out:
A fast moving stream of air will carry more dust
than a slow one. If you blow the fan in, it will
carry dust into the box which will drop out before
it exits at slower speed (because of the much larger
area of all the vents and other openings) - it also
causes dust buildup to concentrate that certain
points bacause of sudden changes in airflow (you can
often see bands of thick dust in boxes with fans
improperly installed). Going the other way reduces
the entry speed (same reason) and thus the amount of
dust that enters - what does get in tends to settle
out in a more uniform distribution.
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
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