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Reverse Blowhole?

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Apr 10, 2001
St. Louis, MO
I've heard both stories as to why blowholes are good and bad. Bad because they divert airflow from the CPU and good because they eliminate the hot air that could get trapped in the top of the case thus increasing overall case temp. What about putting in a fan that actually sucks air from the outside in from the top? To me, it appears this would fix both problems. It would increase the airflow in the case thus adding to the airflow used by the CPU and it would eliminate hotspots but "churning" the air up at the top of the case... Is this correct or should i go back to physics 101.
Case cooling is like a carburated automobile, You put the biggest CFM carb on it, but it does absolutely no good if you exhaust is Too small,
I have a modified Antec SOHO 1030x case, i put 2 92MM fans in front for intake, another 92mm fan On side panel almost above the cpu, i have 2 80 mm fans in back for exhaust, temps were a bit on the warm side, so I got my trusty C.D. sized hole saw out and "augered" a hole for a 120 mm Fan at the very top of my case, and made that so it was sucking air in....NO NO.. temps got warmer, so I "flipped" the 120 mm fan so it was blowing out the top of the case, OH MY GOD...this made such a difference in system temps, If I remember right, my CPU temp DROPPED 5 degrees Celcius, keep in mind at the time I was using a Global Win FOP-38 Heatsink,
THe key here is too get the heat out of the case, not to bring as much cool air in as possible, after all what good is cool air if you cant get it out of the case, oh and 1 more thing, all of my case fan are "U.S. Toyo" and move a good amount of air.......................this message will self destruct in 5 seconds
I've always found that fans near the top of the case should suck air out and fans near the bottom should blow air in. Heat rises so the top 'blowhole' should suck all the hot air out of your case.
i have two 80mm blowholes exhausting out the top of my case, and one 120mm (the cfms balance out) sucking in at the bottom. the noise was bugging me the other day, so i switched them off. and then watched my cpu and case temps climb and climb and climb.. there is a definite 5c to 8c temperature drop with my fans.

i think blowholes are worth it, but they are loud. if you don't like noise, then don't get blowholes.
It is a fact of life that hot air rises, so invariably the higher your cool air source, the warmer it will be. That is why most recommend low intake and high exhaust.