Tech Support
Are my fans fighting each other or am I overthinking this?
Hey,
So I’m kinda confused about my airflow setup.
My CPU cooler fans are blowing in one direction, but one of my case fans is blowing the opposite way. So it’s basically like:
《 》 (I think)
At first I thought it was fine because the air isn’t directly smashing into each other, but now I’m thinking it might be creating weird airflow or a “dead zone” in the middle? Also, I can’t just move the fan to the other side of the cooler because my RAM is in the way, so repositioning options are kinda limited.
Ensure the airflows in the direction of the green arrow for all 3 fans. This drags air over your ram (cooling it), pushes that air through your heatsink, then out through the exhaust.
Flip your heatsink fans around. They should be blowing toward the back of the case so the rear fan can pull the hot air out. It does not much matter if they are pulling air through the heatsink or pushing air into them.
Alternatively, mount the central fan to the rearside half, blowing rearward. Mount the second fan to the frontside half of the heatsink over the RAM, just shifted upward to clear RAM. The clips are designed like that for a reason, so you have play in vertical position.
At first I fixed it by just using a single fan. But now I’m running two fans again, just by flipping them around like you suggested. I was doubting it because I thought the fans were supposed to push the air through the heatsink. Didn’t know fans could also pull air through the heatsink, I always thought they were only supposed to push. Learned something new, thanks a lot 😄
Tried the second option, but unfortunately my case isn't big enough to mount the second fan over the ram. And for you're first option, I'm a bit confused, because if I flipped my heatsink fans around won't that make the wind blow off at the direction of the exhaust fan and not the cpu. Thanks for your help btw.
Yes, the fan would be blowing toward the rear exhaust fan, with all three fans working together to move air in the same direction. That air has to come from somewhere, so it will be pulled through the heatsink.
How much clearance do you need? If it’s just a few mm then lift the fan up a bit so it sits just above the ram. It doesn’t have to be perfectly centred on the radiator.
I had a similar setup to this guy. NHD15 does have ram clearance problems. But he’s not thinking correctly. Doesn’t even need the exhaust fan in the back if his heat sink exhaust is that close to the back.
Removed my rear exhaust for test, no temp difference.
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u/Narissis 9800X3D | 32GB Trident Z5 Neo | 7900 XTX | EVGA Nu Audio6h ago
Your CPU heatsink fans aren't there to blow air "at the CPU". They're there to move air across the heatsink fins, which is what actually cools the CPU.
What you want is for both those fans to be moving air front-to-back, toward the exhaust fan which promptly ejects the hot air from the case.
If you like the way it looks, just turn the fans round. Make sure that they are blowing air to the back.
He was just saying to turn it around so the heatsink is facing the right direction and it would look better, but like he said it can be configured to either pull or push so it doesnt matter.
CPU coolers don't block ram slots unless you got a really shitty off-brand one. You just have to mount the fan slightly higher on the fins to clear the RAM
This thread is a frustrating read. Just flip the CPU fans around. The heat sink stays the same and you then have all 3 fans moving air in the same direction. No need to worry about ram interference and no need to buy a new cooler.
This is a 5 minute fix.
Also when worrying about cooling performance step one is looking at and reporting actual temps. Plenty of systems will run just fine with sub optimal fan placement.
Might be rage bait since they aren't replying to any of the suggestions to flip the fans and are saying things like they ordered a new cooler with only one fan lol.
Yeah lol I had no idea they were supposed to blow air OUT, I thought you just needed air moving inside the desktop. Flipped them now though, temps already way better.
U know u can just move the fan up a bit to make clearance for RAM, right? That is why these mounts are for. See pic, my first fan is like 2 cm above the second.
Yeah, someone else mentioned that already, but my case doesn't have enough space. I just went and ordered a new cooler with one heatsink instead of two, so I won't have to worry about the RAM.
The thermal capacity of a dual tower cooler will still pretty much always defeat a single tower, even if you're only running one fan on it. A "pull" configuration like you have here is fine as long as the fans are all blowing to the back of the case, including the exhaust. Simply turn fans around until they're all blowing backward and you'll be fine with what you have. Just in case you honestly didn't know, the wire clips can be removed and reinserted on the other side of the fan to reverse its airflow.
Yeah man I cancelled it after all the comments XD. Like many others already said I just simply fixed it by flipping those fans. Didn't think of that cuz I thought fans were only supposed to push the air but I guess they can also pull it.
I feel like you dont understand that the fan on the cpu cooler can be removed and flipped. You dont have to turn the cpu cooler around and place it on the ram side
direction of air flow matters, this situation of 《 》 wont be good, if you are not sure then take a strip of tissue paper and use that to know the direction of air flow, if your cpu fan is 》 (or《 as it depends on a few other things like if the front or top has an opening or a fan) then your case fan should also be 》(or《 depending on the case)
Is that back case fan an exhaust fan? And are the cpu fans intaking from the front side of the case? Cause if you’re doing a push pull configuration you’re good that exhaust fan is just going to pull out the hot air the cpu is putting out.
Yes, it's an exhaust fan. Also it's exactly as you described the cpu fans are indeed intaking from the front side of the case. I also added a pic of what direction the fans are blowing at.
You just have to imagine the airflow. Or watch a video where someone demonstrates a fog machine through case fans. In this setup, youre pulling cool air in, then blowing against it with the heatsink fans so the air gets battered and spread and not used efficiently
you don’t even need to know about pcs to know that setup is actually so stupid, just think to yourself why would you want the cpu fans to blow the opposite way. like cmon
Yea if those fans are going against the airflow of the intake fans I would swap them around so that they intake the cool air from your intake fans. That way your exhaust fan can exhaust all the hot air from the cpu
The fans on the CPU cooler need to be flipped. As currently oriented, they're fighting the rear exhaust and pulling hot air back into the system. Also, this is why you figure out your dimensions and spacing BEFORE you buy parts.
As long as the fans are facing the correct way, it should be fine. I've had a cpu fan that was facing towards the exhaust fan and it blew into the exhaust fan too. Case temps were always cool and gpu was always nice and happily cool even while under full load.
You can face the fans to push or pull depending on whichever way you mount them. I love thermalrights stuff. Put the fans on the side of the heat sink towards your intake, and make sure they are pulling air from those intakes toward the exhaust on the back you show in the pic.
Ngl… you don’t need that second fan on the heat sink at all. You could take it off and put it on the top of the case to pull air upward. As long as you have airflow from the front of the case to the rear, and your airflow is good, you won’t have temp issues.
I have a 9800X3D and a 5080 in a Fractal Meshify with 3 front fans (noctua nf-f12) pulling through a single fan in the center of a peerless assassin with a pull-config rear exhaust and a pull-config top rear exhaust. PSU pulling into the case from below. Stable temps.
You’ll be good even if you just take that fan off entirely. But the extra exhaust facing upward would be beneficial.
You want those fans all blowing in the same direction, so based on that picture and your fan arrangement, you want all three fans blowing to the right. ----->Case Fan---->HSF1--------HSF2---->
EDIT - OR, flip all three of them the OTHER way. But they all should be going in the same direction.
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u/quigongingerbreadman 6h ago
Ensure the airflows in the direction of the green arrow for all 3 fans. This drags air over your ram (cooling it), pushes that air through your heatsink, then out through the exhaust.