[Pc_Support] Case airflow dynamics?

[Jason Boxman]

On Sunday 02 April 2006 20:38, Justin M. Keyes wrote:
<snip>
> Probably you know this already, but, Bryan's advice over the years has
> been: (1) airflow coming in (from the front) is more important than
> airflow/fans in the back, i.e., getting cool air IN is more important
> than getting hot air OUT..

Yes, I got that impression from threads at Silent PC Review, too.  I was 
hoping the 12cm bay cooler @ +12V would be pushing in more air than I was 
sucking out, giving me some positive air pressure.  Perhaps it isn't, though, 
or that's not my problem.

> (2) the fans should generally be blowing in the same direction--having
> a fan blowing out of the back, and another blowing out of the top, and
> another on the side, is counter-productive;

I try to avoid that.  My workstation actually has a top fan blowing air into 
the case, since there's no front intake, and then one out the back blowing 
air out.  It seems to be working pretty good, even @ +5V for both 8cm fans.  
The PSU has a huge 12cm that's usually spinning very slowly.

> (3) contrary to common sense, a closed case (with proper airflow) is
> cooled better than an open case. Not sure how that relates to your
> experiences with the front slot.

Yeah, that was my understanding as well.  I must not be getting enough air 
into the case, as removing a single plastic panel ought not to allow so much 
fresh air in that that is helping cool things done.

On the plus side, I did manage to avoid electrocution while replacing a 8cm 
fan in an old Enlight PSU that was nearly loud than the six drives in my 
H700A tower.  It would constantly whine, on and off.  After removing it I 
noticed the 8cm fan was date stamped from 1998.  I guess it was running dry, 
oil-wise.

-- 

Jason Boxman
http://edseek.com/ - Linux and FOSS stuff