CPU fan to blow air on cpu or away? which one?

[DisposableHero]

above

 

[V]

It usually sucks air from the CPU heatsink.

 

[Shmorq]

IT depends on the HSF manufacturer, but I thought it was primarily made to blow on the CPU...

 

[xtreme2k]

All CPU heatsink fans BLOW air to the CPU. Except Alphas. But even with Alpha heatsinks, their fans are just standard fan put in the opposite way.

 

[Hanpan]

Ask mikewarrior in the cooling forum. Afaik there are different combinations whicher work better. For example i heard sucking works better on some alpha heatsinks but blowing works better on most heatsinks.

 

[Killbat]

I've only seen fans blow on the HS.

 

[4824guy]

You want top blow into the heatsink so heat cools it off, by forcing air thru the fins.

 

[Duvie]

I think it has to do with the way the alphas fins are...otherwise with most HS the method of blowing air onto the HS is far more efficient.

Overall it pulls air from further away from source of heat (thus cooler) and scours down onto the surface area of the fins thus reducing temperature...I tested it out with my HSF and it raised temps 3-4celsius the other way as well as raised rpm rate of my fan as it had to spin faster to achieve same rate of cfm. I liken this to putting a box fan tight up against a flat wall. The fan doesn't seem to push the same amount of air as it fights to suck air in the back from the small crack between wall annd box fan...Now this is more extreme but I think it goes to explain the ability of the fan to pull air from an area that is blocked at least 50percent by the surface of the the top of the fins, thus constricting it.

 

[noxipoo]

all the ones i've used blow on it.

 

[John]

I think Kanie Hedgehog's suck instead of blowing. I have mine sucking at least.