Push or pull through radiator ?

Gripen90 · 30 Aug 2019 at 00:30

Getting ready to build my ITX machine this weekend (motherboard arrives later today), I want to put my Corsair H100X into use. Instead of using the stock fans I am using the Corsair ML120 Premium fans. However I am unsure whether to mount the fans in a push or a pull configuration ? The radiator will be top mounted, and the fans on the radiator will be the only ones in the PC except for the fans on the graphics card (open shroud with dual fans). I want the best airflow environment/best thermal dissipation that is possible in this ITX case (Sharkoon QB One) when using this AIO solution.

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pastymuncher · 30 Aug 2019 at 08:21

Push or pull makes very little difference to a radiator's performance. However, if you are talking about having it set up as a intake or exhaust I would set it up to exhaust out of the case and the pictures seem to show exactly that. ITX cases tend to be thermally challenged so the last thing you want is for the radiator to dump it's heat inside the case.

ttaskmaster · 30 Aug 2019 at 10:34

Oblivion007 · 30 Aug 2019 at 13:49

Push/Pull difference is negligible - so just do what works best for your case.

Gripen90 · 30 Aug 2019 at 14:36

Thank you for the replies

I will set the fans to exhaust. Picking up the motherboard in a few minutes so the build can be done tomorrow - finally.

alec · 30 Aug 2019 at 15:19

2c for intake fans

I think I saw it in buildzoid video building a pc with fans on intake push through radiator effectively exhausting hot air into the case.
Justification made sense, you want to cool the water in the radiator the most effectively (by cold outside air), so that CPU temp is lower. All other components only care to have some air moving around, not that it is 10C lower.
The hot air from gpu will still get exhausted by positive pressure.

If these are the only fans it also makes sense to put them behind a dust filter on intake.
The alternative exhaust configuration would mean dust will get in through all other holes and you can't filter all of them.

Edit: confused push and pull with intake and exhaust.
fans should be blowing into the radiator, not sucking from radiator. So always push.

Ross Thomson · 1 Sep 2019 at 21:33

push as an inlet

MikeTimbers · 2 Sep 2019 at 15:22

Ross Thomson said:
push as an inlet

... if the inlet already has a filter before the fans, otherwise all the dust will build up between the fans and the radiator making cleaning a PITA. If no filter, consider buying filters or put the fans on pull so that the radiator is easy to clean.

delvey · 10 Sep 2019 at 20:42

I have a Corsair Air 240, two fans intake from the top, two slim fans at the front exhaust, through the radiator

Drumroll · 10 Sep 2019 at 21:54

pastymuncher said:
Push or pull makes very little difference to a radiator's performance. However, if you are talking about having it set up as a intake or exhaust I would set it up to exhaust out of the case and the pictures seem to show exactly that. ITX cases tend to be thermally challenged so the last thing you want is for the radiator to dump it's heat inside the case.

This. Forcing warm/hot air out would naturally suck cold air in. I would go with exhaust.

Grim5 · 11 Sep 2019 at 01:36

Pull for air coming into the case
Push for air going through the radiators

_tucker_ · 11 Sep 2019 at 07:26

I believe the only difference really between the two is less strain on the fan in push but negligible

Ross Thomson · 11 Sep 2019 at 09:29

Michael Marini said:
This. Forcing warm/hot air out would naturally suck cold air in. I would go with exhaust.

Forcing cold air in would push hot air out. The temp difference of air passing through the fins isn’t much.

LuckyBenski · 11 Sep 2019 at 09:56

Ross Thomson said:
Forcing cold air in would push hot air out. The temp difference of air passing through the fins isn’t much.

Except a radiator as intake means the cool air from outside is heated before it enters the case...

ttaskmaster · 11 Sep 2019 at 11:07

Gripen90 · 11 Sep 2019 at 16:46

I ended up trying 3 sets of fans all pushing the air through the radiator and out up the top. I had originally installed the Corsair ML120 Premium fans, but they were just way too noisy at 1500rpm (they are rated at 2400rpm). At full rpm they sound like a couple of Pratt & Whitney F100 turbofan engines. The performance at 1500rpm was also quite lackluster on my Corsair H100X where the temperatures at max load (running AIDA 64 / OCCT) on the Ryzen 9 3900X would hit around 92~95°c, at a bearable noiselevel.
I then ordered a set of 2 Noctua NF-F12 PWM Chromax Black fans and 2 Noctua NF-A12x25 PWM fans. The latter weren't in stock at the time of ordering so I recieved the NF-F12 first. And they were soooo much quieter running at their max 1300rpm than the Corsair ML120 at the same rpm, and the temperatures were also much better now stabilizing at 84°c at max load (AIDA 64 / OCCT).
However today I got the NF-A12x25 PWM fans, and I thought what the heck I'll give them a try. And I must say these are absolutely beasts running at 2000rpm they are ever so slightly louder than the NF-F12's at 1300rpm. The load temperatures now stabilizes at a constant 79°c during AIDA 64 / OCCT stresstesting. So while the colours don't match particularly well with the brown/beige of these fans instead of the Black Chromax fans, I dediced to keep them in the ITX build because they cool so well with a minimal noise increase during absolute load which the PC never will reach during normal usage.
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zx128k · 12 Sep 2019 at 06:23

Push-Pull did not change my maximum temps by anything over just three fans pushing. Wow that is one small case.

Drumroll · 12 Sep 2019 at 09:37

zx128k said:
Push-Pull did not change my maximum temps by anything over just three fans pushing. Wow that is one small case.

Usually don't, unless there isn't enough radiator surface. Allows for lower rpm to achieve same results. But never needed to run any half decent fan full speed to keep the coolant at optimum temperature.

red eye · 12 Sep 2019 at 23:30

delvey said:
I have a Corsair Air 240, two fans intake from the top, two slim fans at the front exhaust, through the radiator

You have a filter for the top? I have the bigger air case. I brought one of them magnetic decifilter things works well but only lasted a few months before it started to sag and catch the fans

3t3P · 2 Oct 2019 at 00:14

Pull as exhaust with anti- draft foam material sandwiched between spacers acting as a plenum.

Gentle typhoon fans , the masters of static pressure.
They will last forever