AIO Cooler - which fan direction is best?

Hi.

I have a Corsair H100i Pro 240mm AIO cooler for my Ryzen 5800X and it is working pretty well, though it doesn't cool quite as well as I think it should. Right now I have the fans blowing out through the radiator from inside the case. That is to say that it is blowing air from inside the case to the outside. I am starting to think that this might be a little sub-optimal as I am blowing warm air through the radiator. I have four 120mm case fans for fresh air intake and exhaust and good dust filtration, so dust is definitely not an issue.

So I ordered a pair of Noctua fans which are rated for water cooling radiators. My thought is to mount them so that they suck air through the radiator from outside the case. I am thinking the air will be cooler than what is inside the case, but will that cause an issue with heat buildup inside the PC's case?

How do you folks with watercoolers do it?

Catnip said:

Hi.

though it doesn't cool quite as well as I think it should.

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what temps are we talking about here? Idle and loaded.

Catnip said:

Hi.

I have a Corsair H100i Pro 240mm AIO cooler for my Ryzen 5800X and it is working pretty well, though it doesn't cool quite as well as I think it should. Right now I have the fans blowing out through the radiator from inside the case. That is to say that it is blowing air from inside the case to the outside. I am starting to think that this might be a little sub-optimal as I am blowing warm air through the radiator. I have four 120mm case fans for fresh air intake and exhaust and good dust filtration, so dust is definitely not an issue.

So I ordered a pair of Noctua fans which are rated for water cooling radiators. My thought is to mount them so that they suck air through the radiator from outside the case. I am thinking the air will be cooler than what is inside the case, but will that cause an issue with heat buildup inside the PC's case?

How do you folks with watercoolers do it?

Click to expand...

Your CPU will run cooler with the aio as an intake. That is the best configuration for CPU cooling. The down-side is that it will dump warmer air into your case, so your RAM and GPU will run a little hotter. Another advantage, if you have a mesh style case, is you won't need as many case fans.

I have a 360mm AIO pulling air into my case from the front. The fans are pulling in air through the radiator. I tried with the fans in front of the radiator pushing air through the radiator into the case. The pull gave me better temperatures than the push. Pull is also a little quieter because the fans sit behind the radiator.

badrobot said:

what temps are we talking about here? Idle and loaded.

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Idle: 35C. Under load: a little less than 65C. Room temp is 21C.

I have checked the seating of the cooler on the CPU and it has fresh thermal paste, properly applied. I have the fan and pump curves set at extreme. I am hoping the new configuration will cool that down a little.

@geneo Thank you for the answer. This was my thinking as well, as it sounds more logical than what I am doing.

I forgot to mention that the Noctua fans I ordered are the NF-A12x25 PWM versions.

Catnip said:

Idle: 35C. Under load: a little less than 65C. Room temp is 21C.

I have checked the seating of the cooler on the CPU and it has fresh thermal paste, properly applied. I have the fan and pump curves set at extreme. I am hoping the new configuration will cool that down a little.

@geneo Thank you for the answer. This was my thinking as well, as it sounds more logical than what I am doing.

I forgot to mention that the Noctua fans I ordered are the NF-A12x25 PWM versions.

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Those are good fans. I have the Phanteks T-30 120mm which are the same technology and similar performance as those Noctua (but 5mm thicker). So that should run quiet and move some air, they are an excellent choice.

Catnip said:

Idle: 35C. Under load: a little less than 65C. Room temp is 21C.

I have checked the seating of the cooler on the CPU and it has fresh thermal paste, properly applied. I have the fan and pump curves set at extreme. I am hoping the new configuration will cool that down a little.

@geneo Thank you for the answer. This was my thinking as well, as it sounds more logical than what I am doing.

I forgot to mention that the Noctua fans I ordered are the NF-A12x25 PWM versions.

Click to expand...

anything between 40c and 65c is normal.
Gaming temp between 70c & 80c is a safe range.

I checked the manual for your AIO cooler and saw this:

Attach the radiator and the fans as shown. For the best cooling performance, we recommend mounting the fans as an air-intake to your PC case.

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There is been some discussion about this in the past. I read on this after I installed my first Corsair AIO over 10 years ago.

The main conclusions were this:

• The benefit of setting up the fan(s) as air intake gives a cooler CPU temperature. Note this assumes the fan is mounted so it is blowing air through the radiator.
• The downside is that you are blowing warm air inside your case.
• There is no best setup. It is a personal choice.

Well, I got the Noctua fans in and they are sucking air from outside the case. They run a lot faster than my old Corsair fans but they sure are quiet. Looking at Hardware Monitor, the temps haven't changed much, and I thought they would come down a little. I did find a fan outlet on the back of my case right next to the watercooler rad, so I might pick up another Noctua 80 mm fan for that. I have a 120 mm on the back of the case right now, but the 80 mm might help to pull some of the warm air out of the case. That's my thought anyway.

My Ryzen 2700x temperatures are around 29C at idle and about 55 under load (not gaming) as a comparison, and it just has the stock AMD Wraith cooler. I know that my 5800x is 125 Watts rather than the 2700x's 65 watts, so I guess that is what is making the difference in the temps. I'm going to keep an eye on my AIO after I refit the head of it and apply new thermal paste.

I run like this and it is perfect. NZXT Kraken Z73 on top of the case with AMD Ryzen 7 5900X

Lol. No doubt it runs perfect.

Catnip said:

Lol. No doubt it runs perfect.

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hahahahahha yeah with so many Lian Li fans

I like the temp display on the on the cooler plate.

SoFine409 said:

I like the temp display on the on the cooler plate.

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Ye it is nice you can add gifs to it but i prefer temp display

In a similar (same?), case, I have my 360mm Corsair Elite Capellix AIO mounted vertically in the side/front, with the fans blowing in. (I didn't spend the extra $100 for the LCD display.) The hoses connect to the top of the radiator.

Some makers don't recommend that configuration, but it does place the top of the radiator above the pump, so there will be no air trapped in the pump. (Air in the pump is supposed to shorten its life, in addition to reducing coolant flow.)

My idea was to provide maximum cooling for the CPU (I9-13900K). The downside is blowing warm air into the case. I hope that the additional seven 120mm fans take care of that.

None of my fans are RGB (I replaced the ones on the cooler with quieter ones), so there's not much point to my adding pictures.

What you really need to do is to have enough fans pulling in fresh/cool air into the case, so that you produce a slight overpressure in there. This way any radiator fan, or any fan really, pulling air from within the case will have enough physical air molecules to move. This way all components that are not cooled by a water loop also gets a little bit of a fresh breeze to stay cool while also any radiator will work better.

Here's my view on this interesting topic.

As some will have seen from another thread, I started here at Eleven Forums I will be building a new Intel i9 13900k based system in May.
I will be getting my new 360mm Corsair Capellix AIO cooler soon. In addition to the 3 fans on the AIO it will have 7 other fans in the case.

I've done extensive research on the direction of fans in cases with AIO cooling and the only conclusion I've reached so far is that it is a case-by-case decision (pardon the pun) what is the best setup.

Corsair and MSI on their respective websites recommend that the AIO fans should be configured as intakes. MSI did extensive testing on this.
I have also seen many posts on forums and YouTube by people who have done testing in their PC's with the fans in multiple configurations (including AIO fans as exhausts). Some report big differences in temperatures whilst others reported minimal changes.

I do think tweaking the speed of the fans is another key factor in finding a good cooling setup.
What is the PC being used for? Games, heavy productivity and/or content creation?
Does the PC have a high-end GPU?

The only conclusion I've reached about all this is to do testing of different fan configurations and see which one is best for ones PC.

Catnip said:

Idle: 35C. Under load: a little less than 65C. Room temp is 21C.

I have checked the seating of the cooler on the CPU and it has fresh thermal paste, properly applied. I have the fan and pump curves set at extreme. I am hoping the new configuration will cool that down a little.

@geneo Thank you for the answer. This was my thinking as well, as it sounds more logical than what I am doing.

I forgot to mention that the Noctua fans I ordered are the NF-A12x25 PWM versions.

Click to expand...

BTW I get less than 1c above ambient temperature at idle with my configuration and AIO. I have two temperature probes in the front of the radiator which I average (ambient) and two behind the fans which I average (radiator exhaust). At idle, the difference across the radiator is 1c, so at 21c ambient I get 22c cores at idle . At extreme stress load < 8c. This should give you an idea of the range of how much hotter your graphics card will run with this configuration (assuming no other cooling directed at graphics).

The columns are from Hwinfo and the columns are current, minimum, maximum, average (I had a space heater running so high ambient)

If you really wish to stress test your CPU's cooling, I suggest trying Cinebench R23. I haven't found anything else as brutal.

This is slightly off-topic, but for LGA 1700 (Gen12 and Gen13 Intel CPUs), you may get a cooling improvement by using an alternative CPU hold-down frame. The OEM mechanism may bow the CPU. This is an inexpensive one, but it may be as good as any.

My testing was unsystematic, but I think I saw a few degrees C drop with it.

I did a bit more fooling about than usual because the I9-13900K tend to go into thermal throttling (100° C) under heavy load more easily than any previous CPU I've owned.

According to Intel, its use may void your warranty.

bobkn said:

If you really wish to stress test your CPU's cooling, I suggest trying Cinebench R23. I haven't found anything else as brutal.

This is slightly off-topic, but for LGA 1700 (Gen12 and Gen13 Intel CPUs), you may get a cooling improvement by using an alternative CPU hold-down frame. The OEM mechanism may bow the CPU. This is an inexpensive one, but it may be as good as any.

My testing was unsystematic, but I think I saw a few degrees C drop with it.

I did a bit more fooling about than usual because the I9-13900K tend to go into thermal throttling (100° C) under heavy load more easily than any previous CPU I've owned.

According to Intel, its use may void your warranty.

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I always use Cinebench R23 for stress testing.
Re the Contact Frame's the inexpensive Thermalright ones are available where I live. I am not sure if I will buy one with Intel making noises about voiding the warranty.

bobkn said:

If you really wish to stress test your CPU's cooling, I suggest trying Cinebench R23. I haven't found anything else as brutal.

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Try Prime95