Korth wrote:
Front rad with nine (3x3 push-pull pairs of) 120mm fans. Exhaust or intake?
And four 120mm exhaust fans ... where?
And a 5400rpm fan somewhere inside the cabinet. Exhaust or intake, where, on what component(s)?
And a 120mm intake fan over the HDD rack.

Your system specs include "completely water cooled" Mountain Mods Ascension Case, with an EATX R5E mobo, Swiftech Apogee HD CPU cooler, and one GPU card.

But you just keep stuffing more and more fans into the case?
Efficient cooling is not about sheer quantity of fans in the chassis. It's about airflow through the chassis, across hot components.

You need to have some intake fans, some exhaust fans. You need to weigh the merits of Positive-pressure vs Neutral-pressure vs Negative-pressure systems. You need to place your fans strategically, to balance cool air getting into the case and warm airflows across sources of heat and hot air being exhausted from the case. You need to eliminate or minimize "dead air" and "recirculation" zones, you want every Watt and rpm to work towards cooling the system instead of against each other.

Maybe you already know all this, maybe you've already done all this. But your OP question lacks these important details.

Front, 1 big messy radiator, 9 fans (120mm) outside, 9 fans (120mm) inside, air in.
Back, right side, vertically, 4 fans (120mm), air out.
Back, left side, up, 1 fan (120mm) for HDD rack, air in
Back, left side, down, 1 fan (120mm) Emergency, air out
Top, room for 4 80mm fans.

There aren't many ways to play around with a cabinet with a limited number of openings for fans. On the right side in the cabinet are all the water stuff, tank, pumps, meters and controllers. On the left side is the MB and, obviously, cooling blocks, the HDD rack card readers, optical drive etc.

The only place in the rack where heat is generated without being water cooled is at the front, right, top side where the Aquaero and other controller stuff for the water cooling is (Front panel, right side).

So, basically, the heat is relatively evenly distributed in the cabinet. The radiator fans can move a large amount of air and keep everything cool, easily, but at a cost of much noise, so I don't want to do that. I keep the radiator fans at an rpm that cools the water well enough to cool the equipment. The warm air, reasonable well distributed since the radiator fans are covering the whole front, has to get out some way. That's where my question starts. Is it better to leave the 4 fan holes in the top open and have all other fans blow air IN and thus, forcing all air out through the top 4 holes?

JustinThyme wrote:
Too many fans for starters. Push pull is not all its cracked up to be and in some circumstances is the fans are not set up with a proper controller they can be detrimental.
Anything going through a radiator should be going out of the case 100% of the time,no exceptions. if you have a 30C loop temp you are effectively dumping 30C air in your case heating it up.

Also reverse the fan on your HDD cage. Everything blowing in should be ambient, everything out heat. Are your graphics cards dumping heat in the case too or are they liquid? I dont know why they bother with the vents in the back of the Strix cards, that heat all goes in the case if its air cooled.

What kind of fans do you have on your rad? Single fans are more than ample at low rpms IF you have good high static pressure fans. I have a 360 rad in the front with 3 120mm fans on the outside pulling out (fit better that way). a 280 rad in the top with with 2 140mm fans pushing out and one 140mm fan in the back bringing fresh air in acroos the MOBO. None of these fans, which are all high static pressure PWM fans are running over 1000 rpms, most of the time in the 800 range. I have the corsair ML series. The rest of the air intake comes from elsewhere. My case stays around 28C with a 22C ambient.

It's hard to have too much of anything, but it's easy to make wrong use of what you have, which is why I asked this question.

Pushing air from within the cabinet out through the radiators sounds kind of strange to me. Sure, the heat won't be as high inside the cabinet, but the water will not cool much, if at all. Heat trapped in the cabinet by the heat from the radiator and HW inside it should be removed from the cabinet in other ways, that's my feeling on the subject. Do you have any examples od your suggestion being a better one?

Push-pull is a good solution if you want to get ridd of more air. You can never expect to get a doubling of the effect by doubling the number of fans, but I would think a 50% increase more than justifies the use of the technology.

Sverre wrote:
Push-pull is a good solution if you want to get ridd of more air. You can never expect to get a doubling of the effect by doubling the number of fans, but I would think a 50% increase more than justifies the use of the technology.

2 fans in push/pull dont meen more air, it just makes it more easy to push air tru a rad.
and for rad fans you need fans that have high mmh20 that is made for using on radiators, not rpm or things like that.
the higher mmh20 the bether it is, and higher speed on a fan does not mean enny thing, too fast and it does not cool well.
ue a fan controller witch you can controll fan speed AND add a temp probe to your waterloop.

kkn wrote:
2 fans in push/pull dont meen more air, it just makes it more easy to push air tru a rad.
and for rad fans you need fans that have high mmh20 that is made for using on radiators, not rpm or things like that.
the higher mmh20 the bether it is, and higher speed on a fan does not mean enny thing, too fast and it does not cool well.
ue a fan controller witch you can controll fan speed AND add a temp probe to your waterloop.

All my fans are based on throughput, not speed. All except a 40mm for a HDD rack (4x2,5") which runs at an insane 5000rpm (it was the best throughput, I didn't notice the rpm, but it's only used when the temps on the HDD's reach 45C) and an emergency fan (which I know I don't need, I might replace it) runs at around 18-1900 at max. I use electronic monitoring of all stages, with Aquaero6xt and other stuff from Aquacomputer.

Sverre wrote:
It's hard to have too much of anything, but it's easy to make wrong use of what you have, which is why I asked this question.

Pushing air from within the cabinet out through the radiators sounds kind of strange to me. Sure, the heat won't be as high inside the cabinet, but the water will not cool much, if at all. Heat trapped in the cabinet by the heat from the radiator and HW inside it should be removed from the cabinet in other ways, that's my feeling on the subject. Do you have any examples od your suggestion being a better one?

Push-pull is a good solution if you want to get ridd of more air. You can never expect to get a doubling of the effect by doubling the number of fans, but I would think a 50% increase more than justifies the use of the technology.

Not true, of course it's not "hard to have too much of anything". Too many fans generate turbulence and compromise cooling. Too many fans generate way too much noise and aren't required.

Justin is correct! Orientating your fans so that internal case air passes through the radiator is a viable option. The alternative is to have the rad fans set up so that cool air passes through the rad [for lowest CPU temp] but also pushes all of the heat generated by the CPU right into the case, resulting in higher motherboard VRM temps, higher graphics card temps etc.

And when we consider that the OP's issue is actually enclosure temps that are too high.... then rad fans orientated to blow out of the enclosure is certainly worth trying. Both orientations are commonly opted for and both orientations are viable.

Justin is also spot on regarding push/pull... in terms of fans, it's all about the velocity of the air that passes through the heat sink or radiator. With push/pull, the velocity of the air passing through remains the same. Extra fans won't increase airflow velocity. What they will do is increase static pressure marginally, and the effect of this is to drop temperatures by just a few degrees. Push/pull is unlikely to cool greater than an extra 2-4 degrees.

A prime example is the the Noctua NH-D15S air cooler. With two fans instead of one, the temp drops only two degrees..

quark54 wrote:
Not true, of course it's not "hard to have too much of anything". Too many fans generate turbulence and compromise cooling. Too many fans generate way too much noise and aren't required.

Justin is correct! Orientating your fans so that internal case air passes through the radiator is a viable option. The alternative is to have the rad fans set up so that cool air passes through the rad [for lowest CPU temp] but also pushes all of the heat generated by the CPU right into the case, resulting in higher motherboard VRM temps, higher graphics card temps etc.

And when we consider that the OP's issue is actually enclosure temps that are too high.... then rad fans orientated to blow out of the enclosure is certainly worth trying. Both orientations are commonly opted for and both orientations are viable.

Justin is also spot on regarding push/pull... in terms of fans, it's all about the velocity of the air that passes through the heat sink or radiator. With push/pull, the velocity of the air passing through remains the same. Extra fans won't increase airflow velocity. What they will do is increase static pressure marginally, and the effect of this is to drop temperatures by just a few degrees. Push/pull is unlikely to cool greater than an extra 2-4 degrees.

A prime example is the the Noctua NH-D15S air cooler. With two fans instead of one, the temp drops only two degrees..

I'm starting to wonder if you guys have ever tried to run a push/pull setup. If I run the fans on one side and hold my hand in front of the radiator and then turn on the other side I can feel a good difference. Not 100% more, but at least 50%. The thing is that the fans on the pull side has to run faster than those on the push side otherwise the push fans has to use power to turn the inside fans as well. I tried a push pull with 2 fans connected to eachother, and the difference in throughput was very noticeable. And an extra 2-4C is everything for noise reduction. At low CPU utilization my radiator will cool the water around 3C, during a stress test it will cool the water as much as 6C or more.

quark54 wrote:
Not true, of course it's not "hard to have too much of anything". Too many fans generate turbulence and compromise cooling. Too many fans generate way too much noise and aren't required.

1. The turbulence is dependent on the way the fans are placed. If you have input distributed on the whole frontside of the cabinet and the output distributed on both sides of the motherboard on the backside of the cabinet, it won't be much turbulence. (I'm not sure what I'll do with the cooling of the rear HDD rack, since that fan, blowing in, will create turbulence on the MB side of the cabinet, I'll probably turn it around and just use it as an extra output.)

2. Within reason there's hard to have too much of anything. It all depends on the setup. People say that I don't need 2 pumps, sure, I don't need 2, but the second one gives me an extra 50% flow, which will cool my system better. When it comes to fans it's exactly the same thing. 2 fans in push/pull, or 2 pumps in series, can run at a lower speed than only one. 2 fans that gives off 25dB (low speed) will give less noise than 1 fan that has to run at 35dB to get the same throughput.

When it comes to hardware, GPU's for instance 1080 sli is hardly worth the cost, unless you run 4K or better, and the games you play (or whatever you use your computer for) really need the extra push. Or running to Xenon CPU's, there are people who do that as well. Most of this only shows up in benchmarks and looks great on the top 10 boards. So, yes, too much is a waste.

If you check my profile you will find pictures of my rig.