How to orient CPU fan? Pics inside!

[Davidelmo]

Hi all,

New i7 920 rig, oc'd at 4.00Ghz but temps under prime95 are creeping towards 90C, which I don't like.

My case is a Coolermaster HAF, so adequate case cooling isn't a problem.

The CPU cooler is a Titan Fenrir. Good cooler but it will only fit 3 out of 4 possible directions because the fan can't go over the memory blowing out the back of the case, because the Patriot memory is too tall.
It could blow downwards, but I don't really see a point in that.. the airflow would be fighting the fan on the top of the case.

So my two options are:
BLOW it out the top
SUCK air out the back of the case

Which is better? I've attached pictures showing total airflow of my case. There is also a side fan blowing inwards.

 

[unibrow1990]

I'd say blow it out the top, having all that warm air from the cpu floating around in the case wont do anything good for temps so your best bet is to get it out of the case as quickly as possible

 

[A Cheese Danish]

I'd also have to say have it blow out the top. Usually is better that way for temps and such.

 

[LittleLizard]

Blow out to the top unless u want to exchange the direction of all your case fans too.

 

[FordGT90Concept]

You never want to suck on the top because it will plaster your case with junk the fan sucked in. Blowing out evacuates the hot air pocket that lingers at the top of the case and also prevents dust, crumbs, etc. from getting in.

 

[chuck216]

Nah the best way to orient the CPU fan is blowing down towards the MB But then again i'm probably one of the few that doesn't use a tower type heatsink.

 

[FordGT90Concept]

Yeah, you want active airflow going through the heatsink (doesn't mater if it is a tower or not)--that is, blow into the heatsink, don't suck. Sucking doesn't move enough air to cool modern CPUs.

If you have a tower heatsink, you want to blow air across the heatsink and immediately have a case fan suck up that hot air and evacuate it out of the case.

 

[Davidelmo]

Hang on guys.. are some of you even reading what I wrote or looking at the pics?

Unibrow: The air isn't hanging around the case with either possible config. Either direction the hot air is being pointed straight at a case fan.

Littlelizard: Why on earth would I need to reverse the direction of my case fans? They're in the best possible configuration.. cold air in at the bottom, hot air out at the top.

And of course I'm never going to have the top fan blowing air in... that's just stupid beyond words!

The question is:
CPU fan sucking to the left and out the back of the case
or
CPU fan blowing upwards, and out the top

Thank you FordGT90Concept for being the first person to answer properly.

 

[satelitko]

...
The question is:
CPU fan sucking to the left and out the back of the case
or
CPU fan blowing upwards, and out the top

Thank you FordGT90Concept for being the first person to answer properly.

Yeah, you want active airflow going through the heatsink (doesn't mater if it is a tower or not)--that is, blow into the heatsink, don't suck. Sucking doesn't move enough air to cool modern CPUs...

So there you have your answer... And although it's a very tiny benefit, you're not forcing the air to go in a direction it doesn't want, which improves fan performance, as hot air tends to go up

 

[Yukikaze]

I run my i7 in a Nzxt Tempest. I oriented a push-pull config on my Mugen 2 blowing bottom->top through the cooler. Both 140mm top fans are obviously exhausting, and the rear case fan is an intake fan - This throws additional out-of-case air into the cooler vicinity and lowers the temps by a couple of degrees when compared to it being an additional exhaust fan.

I also ghetto modded an Arctic Cooling 92mm fan blowing through the I/O panel space (I never use the panel cover) to cool the PWM area. This dropped temps spectacularly, by nearly 30 degrees on the PWMs.

This is the best config for my case, any other thing I tried was worse. This keeps the CPU at around 62c when under load and the PWMs at a slightly lower load temperature.

Hope this somehow helps you out.

 

[FordGT90Concept]

CPU fan blowing upwards, and out the top

This. I'm a little bit concerned about your memory overheating though. Memory is usually cooled by the CPU fan.

 

[Wile E]

Might as well have it blow out the top. The only other useful way would be to have it blow out the back.

 

[unibrow1990]

I misunderstood your second option, I thoght you meant you wanted to suck cold air out the back of your case and over the cooler, that being said i still stand by my original answer of blowing it out the top of the case.

 

[Duncan1]

blowing out the top of the case is the best for your case.

''SUCK air out the back of the case'': Dont even think about it.

 

[HellasVagabond]

Simple Physics


SUCKING AIR INSIDE THE CASE / FOR ALL CASES
Front Fans
Left fans
Bottom Fans


BLOWING AIR OUTSIDE THE CASE / FOR ALL CASES
Top Fans
Rear Fan
Right Fan (if you happen to own a case with a right fan)

 

[MilkyWay]

NZXT TEMPEST

Graphics is wrong it goes in through the fan and out the back

 

[HellasVagabond]

Kieran it is best to have your PSU facing down so it can get COOL air inside it and not hot from the case....Providing the case has a grill on the base for it to get air from...
Also the CPU Cooler fan should Look at the front and exhaust air on the back.....

 

[mc-dexter]

Kieran it is best to have your PSU facing down so it can get COOL air inside it and not hot from the case....Providing the case has a grill on the base for it to get air from...
Also the CPU Cooler fan should Look at the front and exhaust air on the back.....

That all depends, if you have a big enough gap from the floor or desk unit and the base of your tower. otherwise they would be insufficient air being sucked in. but generally it would work best that way.

 

[HellasVagabond]

even if the case is 2cm away from the floor the small ammount of cool air sucked in would be a lot better than much amount of hot air.

 

[mc-dexter]

even if the case is 2cm away from the floor the small ammount of cool air sucked in would be a lot better than much amount of hot air.

The air at that low point inside the case wouldnt be very hot at all though would it, like it's been mentioned, hot air risers.

and 2cm is plenty of space required to have on the underside of tower.

 

[HellasVagabond]

Most cases have 1cm+ of space beneath....The ones with grills on the base usually have 1.5-2cm...
And no the air that the fan would suck is not on the base of the interior, it would be the air surrounding the Graphics card and generally speaking inside a case there ain't much room and so almost every bit of air is hot.

In any case the PSU facing down when a grill is present is the right way, no reason to debate that.

 

[Wile E]

Most cases have 1cm+ of space beneath....The ones with grills on the base usually have 1.5-2cm...
And no the air that the fan would suck is not on the base of the interior, it would be the air surrounding the Graphics card and generally speaking inside a case there ain't much room and so almost every bit of air is hot.

In any case the PSU facing down when a grill is present is the right way, no reason to debate that.

Doesn't always work if your computer is on thick carpet. But yeah, if the bottom vent is unobstructed, the psu fan should be facing down.