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geekhack Community => Other Geeky Stuff => Topic started by: abdulmuhsee on Mon, 25 September 2017, 18:15:54

Title: Are water cooler fans supposed to be intake or exhaust?
Post by: abdulmuhsee on Mon, 25 September 2017, 18:15:54
I'm not sure if I installed my water cooler correctly.  Basically, you put the cooler on top of the CPU, then there are 2 tubes connected to fans that either blow air out or suck it in.  I have no idea if I'm supposed to be blowing or sucking.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: HotRoderX on Mon, 25 September 2017, 18:25:26
Depends on the case and how its mounted. I have my water cooler mounted on the top of the case I have the fans in a intake setup. The Water cooler was mounted to the back fan on my case it be exhaust fan. Screwing up the flow in the case can cause temperatures to go sky high.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: tp4tissue on Mon, 25 September 2017, 18:56:01
doesn't matter as long as you got good seal around the fans

a fan shroud would be ideal, but again, has to have good seal.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: Findecanor on Mon, 25 September 2017, 20:19:01
Are you talking about whether the fans should be in a "push" or "pull" configuration on the radiators, or whether the radiator and fans should be take-in air into the case or blow it out?

Push has often been measured to be only marginally better than pull. It does not make much difference.

Cases are often designed for intake at the front with exhaust at the back or top.
A radiator/fan stack can be in any of these: front intake, top exhaust or back exhaust (often only 120 mm option), it does not matter much for temperatures. The important thing is that intake and exhaust is balanced and that air flows also to the graphics card and over other components on the motherboard.
Because hot air rises, airflow should never be downwards.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: abdulmuhsee on Tue, 26 September 2017, 13:18:29
Alright, thanks for the replies guys.  I thought that I may have been doing something dramatically wrong by setting them for intake.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: jackalopephoto on Tue, 10 October 2017, 13:48:25
Alright, thanks for the replies guys.  I thought that I may have been doing something dramatically wrong by setting them for intake.

Hot air rising is totally irrelevant for cooling a computer case. Hot air doesn't really rise, it floats on top of cooler air, but the flow in a case is continual and far exceeds any amount of temperature stratification. Several times a minute the entire air volume of a computer is exchanged
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: dubious on Tue, 10 October 2017, 13:56:40
Just to restate it in a different way:

Ideally, the radiator would suck in cool air. The radiator cools liquid in your system by passing air over the fins. The cooler the air, the more efficient the cooling. Your system will probably be fine if the fan is pushing air out of the case (passing warm air over the radiator) but your CPU will run at slightly higher temps.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: clappingcactus on Tue, 10 October 2017, 15:54:49
Push/Pull make no difference on cooling potential. There's so much air intake into most cases, and such quick recycling, that it's a moot point.

But it does make a difference for dust build-up. I have three fans set to intake and one set to exhaust in my case for example, all with great air filters on them, to make sure that there's positive pressure inside my case. Positive pressure keeps dust out, and makes cleaning/maintenance a breeze.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: Leslieann on Wed, 11 October 2017, 03:46:41
As mentioned it usually doesn't matter.

Usually...
This only works for normal applications where the system is only a bit above room temp. If you are overclocking and dumping a TON of heat, then you need them exhausting, but odds are if your exhaust temps were 70c or more, you probably wouldn't be asking.
Title: Re: Are water cooler fans supposed to be intake or exhaust?
Post by: JohanAR on Wed, 18 October 2017, 07:03:18
Just to restate it in a different way:

Ideally, the radiator would suck in cool air. The radiator cools liquid in your system by passing air over the fins. The cooler the air, the more efficient the cooling. Your system will probably be fine if the fan is pushing air out of the case (passing warm air over the radiator) but your CPU will run at slightly higher temps.

Usually both the GPU and PSU cool using air from inside the case while blowing heated air outside so if you put the radiator on an intake you'll worsen your GPU cooling (though I doubt it has big enough effect to matter for most users). But if you put the CPU radiator on an exhaust there aren't much left that produces significant inside the case, as all the major components now push their heated air outside. Ideally the radiator should be entirely separated from the case though :)