Direction of CPU Fan

Baker · 23 Jan 2006 at 13:54

My brother asked me this at the weekend, and it was quite a good question because I don't know the answer!

Does the CPU fan blow towards the heatsink to try and cool it down, or away from the heatsink to get rid of the hot air? :confused:

hogfather · 23 Jan 2006 at 13:58

Onto it is best in my experience, but it doesnt makea massive difference.

basmic · 23 Jan 2006 at 13:58

It blows down towards the heatsink.

Lick your hand, and blow and suck air to/from it. Which is most effective at cooling?

Baker · 23 Jan 2006 at 14:01

basmic said:
It blows down towards the heatsink.

Lick your hand, and blow and suck air to/from it. Which is most effective at cooling?

Sucking because my breath is warm.

Street · 23 Jan 2006 at 14:02

I've had this arguement with my housemate loads of times... he is of the school that the fan should "suck the hot air away from the heatsink"... Im of the school that that is a load of carp.

Although he did complain that his Barton kept overheating... I took the heatsink off for him, cleaned it, reapplied the AS5, put it back on and swapped the fan around so it was blowing onto... didnt overheat after that, but he still wont believe me!

Baker · 23 Jan 2006 at 14:16

I suppose it's the job of the other fans to get the air away from the heatsink.

Dennisthemenace · 23 Jan 2006 at 15:01

just about every quality CPU air cooler blows air over the heatsink, and they do it for a reason.

Martynt74 · 23 Jan 2006 at 15:25

It varies from heatsink to heatsink, try both and see which works best for you

aztechnology · 23 Jan 2006 at 15:27

Marvt74 said:
It varies from heatsink to heatsink, try both and see which works best for you

what he said, try it both ways and monitor the temperatures

Baker · 23 Jan 2006 at 15:30

Ah so some do both?

I'm not looking into which is better for purchasing research, I was just curious as to which way it would be blowing.

Thanks for response.

MikeTimbers · 23 Jan 2006 at 19:07

Some are designed for sucking (Alphas) and the one benefit of sucking is that if you then duct the fan to the rear exhaust fan, all the cpu's heat is instantly removed from the computer case.

Defcon5 · 23 Jan 2006 at 22:07

But on a watercooling radiator arnt you suppost to have the fans sucking

Jimbo Mahoney · 24 Jan 2006 at 08:34

Defcon5 said:
But on a watercooling radiator arnt you suppost to have the fans sucking

Yes, but air passes straight through a radiator.

I'd imagine blowing onto a heatsink is (normally) more effective because of the turbulence.