Should my fans blow down or up?

[cursor]

I've just upgraded my cooling! Got an SLK-947U with a Vantec 92x92x25, and I mounted a 60x60x25 Thermaltake fan on top of my 9800 Pro's stock HSF.

The question is, should my fans be blowing down toward the heat sink, or up away from it?

Or is it 6 of one, half dozen of another?

[OSUmaxx]

Almost always, the best results are blowing DOWN onto the HSF.

[archilochus]

If it sucks the air away from the HS it will pull hot air into the HS.
It's rec. to blow cool air to the HS in order to dissapate the heat from the HS.THE FANMAN:cool:

[Mr B]

On very rare occasion, up ("sucking") does actually work better, depending on the specific configuration of your machine. Very rare, mind you. 99+% of the time, blowing down into the HSF is the best direction.

Try both, and see what your temps do...I'm certain as well as those above that you'll get better results with the fan "blowing" (IE... into the HSF).

B.

[dalilman52]

yup id have to agree, blowign down usualy help A LOT considering that i have an intake fan ducted to my hsf blowing down, u get much better results imo
________
Toyota Corolla E70 (http://www.toyota-wiki.com/wiki/Toyota_Corolla_E70)

[zacmyers1]

Hey cursor i live in knoxville TN too lol what school if your in school you go to or what parta town you live in ?

[vejita-sama]

Is it just me or does anyone else have trouble determining which way a fan goes (sucks or blows) unless it's spinning???

[sautegod]

"suck or blow" a question for the ages
my advise is take it however you can get it

[vejita-sama]

"It's Mega-Maid sir. She's gone from suck to blow."

Yes yes, very funny (it's suck btw always suck). But seriously I am slow or retarded or something, I just can't tell which way the fan will move air by looking at it :)

[Jognt]

thats easy........ think about wot it would do to water/air when it would move......

fan blades nowadays are almost always curved, if the fan would spin one way, it would not disturb the air at all, but if it wuld spin the other way then the air would move, so you can easily see how it would move, thus u would know where the air would be going....

[archilochus]

It is usualy indicated by arrows on the fan frame (body)!!
The rotation and the air flow direction.Little bitty arrows!!
THE FANMAN:cool:

[Tazon]

Please try to picture this and tell me how it would work:

put two 40 mm. fans on the sides of the heatsink, the flapped sides and not the flat sides, blowing air INTO the heatsink, then place the top fan blowing OUT of the heatsink.

or...

the same fan setup, but the 2 40 mm. are blowing out while the top fan blows into. . . naaah i just realized how stupid this would be . . . gotta think before i post.

emilio

[omaticrail]

Originally posted by vejita-sama
...I am slow or retarded or something, I just can't tell which way the fan will move air by looking at it :)

Most fans have an arrow on the side that tells you the direction of flow, but some don't, so do this: Look for the concave (dished like the top of a dinner plate) side of the blade. That faces the exhaust side of the fan...


...unless you happen to meet some !@#$!#$ing dolt that has hooked up the voltage backwards to a DC fan, in which case it won't work for !@#$ no matter which way you face it. :D I saw a guy do that once, and he just would not believe me.