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Very quick airflow question?

post #1 of 5
Thread Starter 
Does the number of fans sucking air in rather than out create positive or negative airflow, based solely on the number of fans if all the fans are the same size and type?

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post #2 of 5
all things being equal, fans blowing air INTO the case creates positive pressure and fans sucking air out of the case creates negative pressure.

most people make the mistake of not accounting for PSU and GPU as exhaust ports.
post #3 of 5
unless your psu is facing the bottom and doesn't put air into or take air out of the case, being in its own barriers. Also many graphics cards dump the air back into the case, not exhausting that much air.

positive air flow = more intake than exhaust
negative = more exhaust than intake

studies have shown that only having a rear or rear + top exhaust performs the coolest
   
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post #4 of 5
Each PC case and hardware is different so no one can tell you exactly what is best for your application. Positive or negative pressure means nothing in the grand scheme of PC case cooling as you can have little airflow in either situation. More fans also does not guarantee better cooling.

What matters most in PC case cooling is having proper air FLOW thru the case to draw the warm air off the heat sinks and then exhaust it properly so there is a contant flow of cool air in and hot air out. There are many ways to achieve this but PC case pressure per se is not a solution or even practical to attempt to measure.

If all fans actually flowed the same volume of air then more fans pushing air into the case than out would be a positive pressure case. The problem is fan air flow changes with air resistance in the case, air turbulence, hardware layout, HSF design and orientation, etc., etc., etc, All of these variables impact air FLOW thru the case and thus the actual temps that your high heat producing devices such as CPU and GPU operate at.

The only means to know what combination of fans works best for your PC is by careful testing. More fans are not always better as turbulence can reduce the smooth flow of air thru your PC case. Test to see what works for your PC case/hardware and enjoy. thumb.gif
post #5 of 5
Thread Starter 
Well thanks everyone, I was only curious because I had a thought that popped in my head 'in the moment' and I needed an answer and you gave it to me OCN! Thanks.
    
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