Overclock.net banner

Does case fan layout matter if watercooling?

1036 Views 13 Replies 13 Participants Last post by  NETio
Just been reading in the Air cooler section that they recommend a 1:1 cfm ratio, mine currently isn't.

I have 2x 66cfm Xigmateks as Intake :

1. One at the bottom of the case with no restriction
2. One mounted to the HDD cage blowing past 2 HDD's

Then I have 4x 66 cfm Xigmateks as Exhausts :

1. 3x on the radiator pulling air though the radiator and out the top of the case.
2. Last one on the back of the case as a normal exhaust fan.

Does it really matter? I meen as long as the radiator gets air being blown/pulled though it surely it should be ok?

I also have a spare 66 cfm Xigmatek fan spare, what should I do with it?
1 - 14 of 14 Posts
i like to have everything but the radiator fans point inward to keep even pressure, and prevent dust from getting sucked in
I would point the one on the back as intake. So it will be 3x66cfm in and 3x66+cfm out. Your psu is also drawing some air out.
Remember that there are other things that need to be cooled as well as the main components. The north bridge and south bridge need air flow as well as RAM if it is not water cooled as well. In addition there are many other spots over your motherboard which can cause heat.
  • Rep+
Reactions: 1
The only thing that comes to mind is that if your radiator fans are in exhaust, and your case has negative pressure, then there will be some reduction in airflow through your radiator. In that respect, positive pressure seems to be the way to go.
Well kinda yeah, Remember if your WCING your other components wil be getting fairly hot also, i Suggest atleast 70+CFM 120mms to anyone so it can help your mobo,gfx cards etc.. 3 intake, 1 exhaust and a top fan etc
on my sig rig i had 3x120 intake (2 bottom front/1 side) and 1x120 outtake (rear back) with 2x140 outtake (top) on rad, it was 1:1 cfm.

i changed the 120 outtake to intake so the only exhaust fans were on the rad and it gave me better cpu and mosfet temps. cpu dropped by ~4c (core temps) and mosfets dropped by like 10c. system temp and video card stayed the same

also i would experiment with removing the rear exhaust completely, since it blowing in could mess up ur overall airflow. try it and see what kind of temps u get on everything, if it hurtz put it back on. just throwing this out there cuz i plan on doin it
i always have more fans blowing air in (more cool air inside) and the cool air sucked out by the graphics card as warm air
.. i use to have like 5 intakes only 1 exhaust.. temps were awesome compared if i change 2-3 of them to exhaust..
See less See more
I think as long as you have smooth air flow paths, it will be better than just matching CFM. I remember an article years ago, I can not site the source though, that using all the same fans, experimented in fan placement using low front fans, side fans, rear fans and top fans, all with either intake or exhaust: one setup with low front intake high rear exhaust, one of low front intake blow hole exhaust, top intakes with front exhaust etc. The setup with only a front intake and a top blow hole exhaust was cooler than the setup with front and side intakes with rear and top exhausts. They attributed it to smoother air flow/lack of turbulance.

Originally Posted by Champian View Post
Remember that there are other things that need to be cooled as well as the main components. The north bridge and south bridge need air flow as well as RAM if it is not water cooled as well. In addition there are many other spots over your motherboard which can cause heat.

The internal space of an enclosed case will still need to breath.

P.S. Love that avy, Champian.
See less See more
I run a push/pull 3x120x38 and 3x120x25 on my bottom mounted radiator in my 1200. With the 1200 (and probably others) you have to give up some of the front fan intakes for "devices' . I managed to save 1 unobstructed and one partialy blocked. I maintained the tops exhaust and upgraded the rear exhaust.

So I experimented, and the results were as long as I was pulling in air through my rad (even if it was rad heated air) and kept the top exhaust going, the front intake and rear exhaust could be turned off, as they had no affect on temps.

I built this rig thinking I would still need all the air moving ability it came with from Antec, but this did not turn out to be true. I am very willing to run fans whereever they are needed but as it sits my push/pull setup and the top exhaust are handling it.

With no high OC added (hence stock CPU voltage) I can lower the voltage to my push/pull group and everything gets very quiet.

Mind you when I am making a 4.0+ghz Prime95 extended run I turn on every fan I have to the max (noise is incredible from those 120x38 Deltas).

Another thing I found is it makes no difference if I run my 655 pump at any setting above "2". 4.0ghz Prime95 runs sit a 44c to 49c depending on ambient temps.

Lets see what a moderate GPU OC does though, just started expermenting with RivaTuner, also my low fan use my not hold up under multiple GPU's. Waterblock for single GPU comes in Jan. ($160.00, very hard to justify)
See less See more
In a HAF932 I have the big side panel fan as intake, and everything else exhausting. I did this because supposidly negative pressure= less dust. I saw no change in temps, except that my hard drive temps actually went down 1 degree c at the same ambients. I have yet to determine if dust is any less.
Fans are still important with watercooling unless you watercool everything in your computer (impossible without oil submersion). Supposedly negative pressure > positive pressure but I personally run 3x120mm intake fans on the front of my case and 2x 120mm exhaust fans in the back. My bottom mounted PSU pulls air in from the outside as well as the inside of the case so it does not contribute to exhaust too much.
Also, direction of airflow matters too. Front to back in a diagonal pattern is the norm for most cases and seems to be universal.
1 - 14 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.