Fan on the heatsink? Blow or Suck?

[rizge]

All the retail fans will blow by default but i have seen a review (don't remember for what) that showed that with some Fans Sucking Hot Water of the Heatsink is better than blowing air into it
Also
I am planning to 4X80mm Fans on my heatsink
All Blowing IN
Shall i put 2 blowing and 2 Sucking?

 

[roYal]

no, don't put 2 blowing and 2 sucking. That defeats the whole purpose considering the fans will be working against eachother. The best way is to trial and error. I have a alpha 8942 and they said it's better to suck, but i found it's better to blow. Also, if you're using more then 1 fan, the fans could get damaged cause of the air flow onto another fans fins. Keep this in mind.

Also, the majority of hsf work better blowing.

 

[Pfieffdog]

Also, the majority of hsf work better blowing.

blowing air onto the HS or blowing it away from the HS?

-Pfieff

 

[roYal]

blowing means onto the cpu
sucking means away from the cpu

 

[Namagomi]

my 8045 is all about the sucking. It decreases CPU temps like 1 or 2C depending on ambient, and it also decreases board temps 4C, because there isn't 80CFM of hot air being blow directly accross my 2200(BTU)+ and then onto the board.

 

[ShadowFolder]

blow r more effective, i think...

 

[Wommalong]

blow r more effective, i think...

Me too, i think you get more air to pass through the heat sink then if you where sucking air through the heat sink ... more resistance... via la resistance lol

 

[Pfieffdog]

I guess I will have to try both and see which ones works best for me.

-Pfieff

 

[flixotide]

The MIST silent twin setup I use is actually a combination of the two principles..

Observe the construction: Piccies

Now.. this construc creates a problem, hot air being pushed against a joint surface, and upwards towards the case side. In order for the entire sink to keep cool, I have to remove this very fast. Usual airflow from front to back isn't good enough. So I have constructed a duct with a sunon 35 cfm fan to suck out the air from right off the top of the heat, thus creating an extremely well working system....

Without the duct, the heat sink would hit 50 c's, and the core diode around 70... with the duct principle, the sink goes 35, the core diode between 50-55.. What a difference.
Cheers, Flixotide

 

[Ugmore Baggage]

Cool air is betterer.

Air floating over the mobo is warmerer so use the fan to blow air downer into the heatsink from the coolerer case air (or even betterer -- a ducter)

 

[Pfieffdog]

Thanks, I'll give it a shot both ways.

-Pfieff

 

[Pfieffdog]

Any more opinons on this?

 

[Namagomi]

ok. excessive bumpage.
try it with the fan both ways. whatever is cooler for you is the way you should keep it =P
overclocking isn't an exact science. what works for me won't always work for you. don't expect any sage advice that will solve world hunger from this board. most of us (including me) are just talking out of our *** most of the time, your best bet is to do some screwdriver work and test it out yourself.

 

[nut581]

if you have good positive case airflow (good = case temp w/ side panel closed is lower than case temp w/ opened side panel), you might want to consider sucking

I found a review earlier
Review
shows that positioning high CFM fan placed on a fan adapter to suck yield lower CPU temp than same fan put to blow.

While you're at it, put on a duct on your HSF, it might get even lower temp since all warm air is blown to outside the case.

 

[Pfieffdog]

if you have good positive case airflow (good = case temp w/ side panel closed is lower than case temp w/ opened side panel), you might want to consider sucking

I found a review earlier
Review
shows that positioning high CFM fan placed on a fan adapter to suck yield lower CPU temp than same fan put to blow.

While you're at it, put on a duct on your HSF, it might get even lower temp since all warm air is blown to outside the case.

Thanks

 

[UnseenMenace]

I personally consider the suck or blow discussion generally always seems to forget one thing and that is the requirements of the heatsink.. Some produce better results having air blown against them and other prefer the latter.. its effectively a case of suck it and see. Whats good for one heatsink may not be so for another

 

[palee72]

All the retail fans will blow by default but i have seen a review (don't remember for what) that showed that with some Fans Sucking Hot Water of the Heatsink is better than blowing air into it
Also
I am planning to 4X80mm Fans on my heatsink
All Blowing IN
Shall i put 2 blowing and 2 Sucking?

Maybe I missed something in the original translation, but, is this an air or H2O system? If it's air, is water on your heatsink a major problem? If it's H2O, do you really want to introduce bubbles into your tubing???


I'm sure you ment sucking hot air... at least... I think...

By the way, I find blowing is much better (hm.... bordering on the limits of the forums with that statment....)

 

[ShadowFolder]

if u have no fresh air on your case,
blowin' works better than suck, i think...

 

[MoPMatrix]

My alpha 8045 blows =)

Fan not the HS

 

[hdj]

It depends on the design of the heatsink. In general, If you have a PIN grid on the sink (Alpha pal, swiftech mcx462) You will want to suck the air out.
If the sink has a FIN design, you want to have the fan blowing.