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I must admit I was quite surprised by the results – specifically, by the fact that using extra fans (one extra for the air cooler, two extra for the AIO) in a push/pull configuration made so little difference.
To put it in plain numbers: across both tests, using a push/pull configuration yielded up to a 4 degree reduction in temperatures. In some cases, the difference was 2 degrees. Why is this?
To answer such a question, I cannot give a definite answer, only a few suggestions.
First, I would point out neither the Cooler Master 212 LED or the Arctic Liquid Freezer 240 are the biggest of coolers.
What I mean is, the air being pushed through each cooler does not encounter as much resistance as if I had been using a 60mm-thick radiator, for example. This would mean using any extra fans in push/pull makes little difference as the air is already flowing easily enough, rendering the extra fans redundant.
Another factor could be the fan speed. I set every single fan used in the test system to run at 50% – this way we eliminated any potential interference from the motherboard's PWM controller. However, I would suggest at a lower fan speed – say 25%, for example – using a push/pull configuration may have made a bigger difference. This would be because less air is flowing due to the lesser fan speed, so adding in the extra fan(s) in a push/pull config could have made a bigger impact as it would have increased the amount of air flowing by a significant margin.
However, both those explanations are just educated guesses – I could not confirm anything until I tested both of those hypotheses as well. I would also stress I am not trying to take away from the results – only to explain why the difference is not as big as I thought it would be.
There is also the small caveat that a test like this is hardware-specific, so I cannot guarantee the temperature difference between fan configurations would be the same 4 degrees across all PC systems. That being said, though, I conducted each test in a scientific fashion and the results do not lie – the biggest gain I saw from using a push/pull setup over a pull configuration was just 4 degrees.
Whether or not this 4 degree difference is significant depends on the circumstances. For example, if your CPU peaks at 50 degrees by default, then there would be little point in investing extra cash for fans to run a push/pull configuration. By contrast, if your CPU is much hotter and is getting close to its thermal ceiling, an extra fan or two would go a long way to bringing those temperatures down to a safer level.
Still – as I said, the data cannot lie. As such, the conclusion I would draw from the data is this: unless your CPU's temperatures would really benefit from a 4 degree reduction in temperatures, fan configuration does not matter that much after all.
KitGuru says: In this article I have shown that, in actual fact, fan configuration actually makes little difference. Still, we want to hear from you on this – so sound off in the comments about what cooling setup you have and whether you think it needs any tweaking. Bonus points to anyone who tells us their max temperature under 100% load!
Well if your within a few c of your cpus maximum temperature your cooling is either insufficient or your overclock is too high
I’ve got my PC (4770k @4.5GHz + 970) setup with a slightly positive interior pressure, and have found this works best for me. I use 2 140mm Fractal R3’s in the front and 1 120mm on the bottom (wood floor, plenty of room) for intake, 1 140 in the back and 2 120’s + radiator on top for exhaust. All inside the Define R5. Use a Lepa something or other AIO. Seeing max temps around 66C on the CPU. Not bad imo.
3770K stock with corsair h75 push pull config with noctua nt-h1 thermalpaste, 65-72 celsius under 100%load, room temp 20C.
I always ask myself a thing when i read about cooler testing: if Amd FX 9590 is the hottest cpu, why use Intel ?
Using a double thickness 240mm with push I get 45C under full load on a 3770.
The difference is mostly just from the flow patterns inside the cooler, higher flowrates change how the air moves within the cooler allowing it to transfer more heat. Basically all that stuff on turbulent or laminar flow and Reynolds number you learned at school.
shouldnt need to test its pretty obvious when it comes to physics push > pull and push/pull > push with just 1 fan.
I agree, a 9590 is a higher heat load but more people use Intel products so this wold be more relatable, and with this being an older HED chip, it would be more likely more people would be running something like this. There is a valid argument either way
Use an infra-red temperature meter (eg in-ear body temperature gadget is what I use). Then work out which parts of the computer are at which temperatures.
Then, using the push-fan, direct the cold intake air towards those hot units: cpu, gpu, hdd, power-supply, etc. I used cut-pieces of (plastic) cola bottles to direct this flow. The dvantage of push-fan is the use of an air-filter to prevent dust rubbish moving into the computer.
Any other air-leaks were sealed with tape & putty-stuff (post-it putty). Other people pipe in cold, fresh air from outside the room (outside & under the building, etc).
I also tried humidified air, to increase the loading of the heat extraction of the “fresh” air. Humidified air can come from a fish-tank, or from a ultra-sonic humidifier injecting water into the air stream.
Extracted-air is higher temperature (& humidity?) than room temperature. So I directed this extracted air out of he room, along with the noise of the PC. Pull-fans help overcome the restrictive friction of any air tubes needed.
Looking at the numbers, push/pull clearly did best under load (this is what you expect from physics too). Cooling under load is what’s important. (I assume the RPMs spin down in idle.)
commence operation vacuu-suck
ye, push is better than pull cause a bit more surface area and more wind force.
Yup. Little difference unless in the push config where someone wants to cool a device such as a hard disk or video card.
As someone mentioned below, the only difference also is in dust control. I have a design that minimizes dust using an all Pull config.
Slim margins, but push confirmed as better than pull. Throwing air in with push obviously works better than the lazy path of least resistance airflow drawn through by a pull fan.
The unconvincing gain of push/pull tallies with the results for pressure vs. flow fans, so long as the back pressure is not limiting the flow, the extra suck from push/pull is not going to make a huge difference.
A two stage tower with mid fan would probably benefit from push and mid
I have a little Question about the Arctic Liquid Freezer in Push/Pull config.
How does it fit in the Kolink Aviator V Case?
Did you put it in the Top Slot or remove the Hard Disk Frame to mount it in Front?
hello, personally i have the same cooler but not the case.
My case is a h440v2, i have removed 3 hard disk “slots” on the front to make a push & pull.
I got it by 11 months, all is ok, but i want to test in future the changes with push or pull on the top.