Positive or Negative Pressure

Positive or Negative Pressure

  • Positive

    Votes: 8 44.4%

  • Negative

    Votes: 10 55.6%
  • Total voters
    18
bomberboysk

bomberboysk

Active Member
Ok, heres something that i find debateable in these forums alot- should you have more case fans blowing out than in(negative pressure), or more blowing in than out(positive pressure).There have been alot of conflicting interests about this, and recently in an article in CPU(or maybe maximum pc, i forget which one) they author recommended positive pressure as it would push the heat out any open vents in a case, while other places ive read negative pressure is better(which is what i have always assumed to be better). And while balanced intake/exhause would more than likely be the best way, What do you guys think about this?(just a discussion btw)
 
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I use negative pressure because I stand by the belief that rear fans should blow out, and front fans should blow in, and I have no other fans in the case besides the power supply fan.
 
Done properly (ie sufficient cooling and acceptable noise levels), positive pressure could have several benefits, primarliy dust ingress prevention and flow control.
 
Negative? Positive? Whats it called when your PS, rear, and top fan blow out. And your two front fans blow in? Don't you want equal pressure? Same amount going in as out.
 
What I've been taught about airflow that I believe is most important is that you don't have fans pushing air against eachother. I would say monitor your temperatures and experiment with air coming in or out of a case.

I am thinking about switching my rear case fan to push air out because it seems to blow dust in.
 
positive pressure=more air in the case.

negative=less air

if there is positive pressure, it stands to reason that more air will pass over the heatsink fins.
 
negative. The fans will suck all of the hot air away and the low pressure means every single hole that your case has will have air coming in, so you get cold air coming from more places and the hot air that it turns into leaves quickly
 
Aastii said:
negative. The fans will suck all of the hot air away and the low pressure means every single hole that your case has will have air coming in, so you get cold air coming from more places and the hot air that it turns into leaves quickly
Click to expand...

Although the same goes for positive pressure... This would make for a good experiment though to do this summer when im bored nonetheless.
 
gamerman4 said:
You know, how bout you all try it out, just unscrew your fans and turn them around
Click to expand...

I would do this... but i have fans i cant turn around in my current case(250mm side fans x2) Im thinking about trying this in an emachines with a single case fan, power supply fan, and cpu fan, and also has a crapload of vents, would see which one is the best actually.

=2400th Post=
 
Doesn't really matter if you ask me....I have 2 blowing in and 2 blowing out. I had to move one fan though due to it actually slowing my CPU fan down and causing issues.
 
My experience with a stock case with about equal pressure - one (in) and one (out). Added a third fan (out) without measurable change in temps. Thought I’d try it blowing in and got about 5 - 6C drop in temps. Seems, in my caseanyway, more cool air in works better than trying to push more hot air out.
 
If i can find a very cheap hard drive i will set up my old system again, good old celeron processor and 512MB memory :P my first WoW playing machine, low settings, 3fps, damn good stuff :D

Stick a fan or 2 in and play with the pressures, measure temps etc. The case it was in, which we still have, has ALOT of holes in, so it would be a good testing rig
 
Aastii said:
If i can find a very cheap hard drive i will set up my old system again, good old celeron processor and 512MB memory :P my first WoW playing machine, low settings, 3fps, damn good stuff :D

Stick a fan or 2 in and play with the pressures, measure temps etc. The case it was in, which we still have, has ALOT of holes in, so it would be a good testing rig
Click to expand...

Sounds perfect to test this out on...Heck, you could try making a livecd of something to test it out without a hdd even.
 
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