17 Jun
2005
17 Jun
'05
9:56 a.m.
On Jun 17 2005, 7:47, Cini, Richard wrote:
Rules-of-thumb like this are great to know.
The fan, I'm sure,
was
installed (like the IMSAI) blowing IN because the
inside was caked
with
dust. So, I made it an exhaust fan (no filter).
As I work on the IMSAI, which has no filter either, I will swap
it
around, too.
Don't do that. If it's designed to blow in, changing the direction to
blowing out will alter and probably reduce the cooling. Why? Because
turbulent air is lots better at cooling than a laminar flow, and will
reach more parts of the case. You get turbulent air from the "blow"
side of a fan, but laminar flow towards the inlet side. You may also
be directing the airflow away fom some component that previously was
cooled, eg a PSU. Moreover, if you alter the flow direction so that
air is being sucked in through all the other orifices, it will be
entering via the fronts of disk drives etc (well, probably not on this
machine but I'm thinking of the general case). That's the last place
you want the dust. Far better it drops on the motherboard where you
can vacuum it out. Better still, fit a filter.
--
Pete Peter Turnbull
Network Manager
University of York