Adding a top fan - blow in or out?

[Munky]

I have a case with a 12cm intake fan up front, and a 12cm exhaust fan in the rear. The case also has a spot for a 8cm fan to mount on the roof of the case, and I was thinking should this fan be blowing air in or out? My PSU has 2 8cm fans also, but they spin really slow, not much of a difference.

 

[CraigRT]

I say exhaust.
Intake should only be in the front of the case...

 

[Reiniku]

Originally posted by: CraigRT
I say exhaust.
Intake should only be in the front of the case...

sides of the case are best as intake as well. hot air rises so it makes perfect sense to push that hot air out of the case upward, making a top exhaust more effective.

 

[Munky]

Thanks for the replies, looks like exhaust is the way to go.

 

[Jotho]

Originally posted by: Reiniku
hot air rises so it makes perfect sense to push that hot air out of the case upward, making a top exhaust more effective.

Exactly true, I would have posted the same thing

 

[Zepper]

It's been shown over and over that blowholes don't add much to cooling. But I would have it as an intake - so when you feed it a coke, it will do a much better job of distributing it evenly throughout your computer innards... 😉

.bh.

 

[Jeff7]

Give it intakes, toward the front and bottom. More intakes means that you can filter more of the air getting into your PC. The filters of course reduce airflow, which is why more intakes can be good. I think easy-to-clean filters should be a standard thing on PCs. Heck, they are on air conditioners - just slide it out and vacuum or wash it. Should be the same way on a PC - dust inside can get to be a real problem, getting into fans, and insulating heatsinks, keeping them from dissipating heat effectively.
Ever open a PC that hasn't been opened in 4 years? The dust bunnies have had a chance to give birth to extended families.

 

[NiKeFiDO]

Originally posted by: Zepper
It's been shown over and over that blowholes don't add much to cooling. But I would have it as an intake - so when you feed it a coke, it will do a much better job of distributing it evenly throughout your computer innards... 😉

.bh.

depending on where you keep your tower, this is a good point.....same with the side fan i suppose if the tower is on your desk

 

[BW86]

Heat rises, make it blow air out. I cut a hole on the top of my 3700amb and my case temps dropped 1 degrees with an intake and 4 degrees with an exhaust. Try it out for yourself and see which gives you better temps.

 

[fireontheway]

Exhaust.

 

[comrade]

Originally posted by: BW86
Heat rises, make it blow air out.