But the issue is still how to do it without a fan motor. In the example
of the Dell, they are substituting a case fan for a fan on the processor
and it would have to have the case on to work properly. It's well known
that ducting and cowlings on fans improve efficiency. The fact that you
do a lot of little things to improve air flow shows you are both
thoughtful and clever.
MonMotha wrote:
I guess you've never used a Dell Dimension XPS Dxxx series tower
system. The processor has a big heatsink but no fan on it. Directly
behind the processor is the case fan. Take the case off an run the
CPU at 100% for long, proc overheats and halts. With the case on, run
at 100% CPU for days, the heatsink is barely warm to touch.
I've actually built white boxes with similar, though not so drastic,
thermal characteristics. When I build systems, I usually consider
airflow from the start, even down to selecting different brands of
video cards due to how far back they extend! I route cables behind
things, twist tie cables next to bracing, etc. all to improve airflow
from front to back (I've even built a wacky system where I flipped the
PSU fan and had air flowing from back to front). Most of my systems,
when I'm done, have case temps within 0-3C of room temp, and CPU
temps within 0-10C of case temp, but I've had systems where, due to
good airflow, the CPU runs hotter with the case off (even though
sometimes ambient system temp is lower) than with the case on. Good
airflow allows for faster evacuation of the hot air produced by the
CPU fan circulating air over the heatsink, thereby lowering the
ambient temperature NEAR THE CPU, creating a greater delta T between
the heatsink and air, allowing for faster heat transfer from the CPU
heatsink to the air.
--MonMotha
