Discussion Adjusting the case airflow

[mahdimz]

I have this fan management for like 2 months, 3 fans at the front as intake and 2 fans on the top and 1 at the back as exhaust.

I had no temperature issues so far, everything seems to be fine but I feel like a part of the top right fan is sucking the fresh air out instead of letting it reach to the CPU cooler but if that's just a stupid assumption, I still feel like that the fan is being wasted and has no impact on the airflow. Since I have a dualtower CPU aircooler (AK620) I feel like it doesn't let any hot air to reach up there at all and already sucks everything, letting the air go through the rear exhaust after all. When the pc is under full load, I can feel the hot air coming out of the rear fan and kind of warm air from the top left fan but the outcome of the top right fan is always cool hence why I feel it has no affect on the cooling system.

I was actually thinking of moving the top right fan to the bottom right or left, under the GPU (Confused if I should make it intake to bring cool air to the GPU or make it an exhaust to take out the hot air of the GPU but also confused between bottom right or left slots too haha), but I'm really noob at these stuff so that would be great to hear your thoughts, thanks.
ps: The case is LianLi LanCool 2 Mesh C

 

[Lafong]

I have this fan management for like 2 months, 3 fans at the front as intake and 2 fans on the top and 1 at the back as exhaust.,,,,,,,,,,,,,,,,,,,,,,I still feel like that the fan is being wasted and has no impact on the airflow.

I still feel like that the fan is being wasted and has no impact on the airflow.

Easy enough to find out.

Disconnect it and compare before and after temperatures.

You have 6 fans.

Experimentation may tell you that 3 or 4 are as good as 6.

No way to find out without testing.

 

[mahdimz]

Easy enough to find out.

Disconnect it and compare before and after temperatures.

You have 6 fans.

Experimentation may tell you that 3 or 4 are as good as 6.

No way to find out without testing.

Yeah I should test it out but I wonder if that also worth moving the fan down the GPU to test that too. Like making it as an exhaust to suck the hot air of the GPU out while the two rear and top fans doing that for the CPU or making it as an intake fan to suck the cool air into the GPU to forward its hot air towards the exhausts above.

 

[Gururu]

I agree with you. That top right fan is likely removing part of the fresh air feed before it can contact the heatsink. Air will move diagonally from the front intakes. Disconnect it see if it impacts anything. If you do move it make sure it fits your current model where fresh air comes in from front and hot air expelled from back. Air flow should be as seamless and unobstructed as possible with heatsinks being the target.

 

[USAFRet]

Yeah I should test it out but I wonder if that also worth moving the fan down the GPU to test that too. Like making it as an exhaust to suck the hot air of the GPU out while the two rear and top fans doing that for the CPU or making it as an intake fan to suck the cool air into the GPU to forward its hot air towards the exhausts above.

Make 1 change at a time.

 

[mahdimz]

I just flipped the top right fan and made it work as intake, but I didn't really see any difference, with around 3 minutes of stress test (Ik it's not a lot), the max temperature was 102 degrees while it was 103 degrees after flipping, also one more CPU core got thermal throttling after the change.

Idk if I should revert it back but theoretically I feel like the new fan management is way more better due to the reasons said at the first post. Maybe I should move the fan a bit to the left, making it to directly blow the cool air into the heatsink?

 

[Phaaze88]

I just flipped the top right fan and made it work as intake, but I didn't really see any difference, with around 3 minutes of stress test (Ik it's not a lot), the max temperature was 102 degrees while it was 103 degrees after flipping, also one more CPU core got thermal throttling after the change.

Idk if I should revert it back but theoretically I feel like the new fan management is way more better due to the reasons said at the first post. Maybe I should move the fan a bit to the left, making it to directly blow the cool air into the heatsink?

A number of things are happening from the fan you flipped:
-it's taking some of the air exhausted by the fan next to it and pushing it back into the case.
-it's pushing against the air coming up from that pass-through on the gpu cooler.
-it's intercepting some of the air coming in from the front.

 

[Gururu]

In the original post, you mentioned the air from second fan outlet was warmer. That makes sense anyway because it is getting warm air from both heatsinks versus the first fan, which is only expelling air from the first heatsink. At this point, I would just make that top right fan running low RPM pushing air in. Maybe serving to vent more than anything. Dont have it so high that it is displacing air from that top front fan. By the way, if the fan is off, does air naturally push out of it or does it flow in from that fan location?

 

[mahdimz]

Sorry for the late response.

In the original post, you mentioned the air from second fan outlet was warmer. That makes sense anyway because it is getting warm air from both heatsinks versus the first fan, which is only expelling air from the first heatsink. At this point, I would just make that top right fan running low RPM pushing air in. Maybe serving to vent more than anything. Dont have it so high that it is displacing air from that top front fan. By the way, if the fan is off, does air naturally push out of it or does it flow in from that fan location?

While idle, it was like a bit of the cool air that is coming from the front fans was passing out from that empty space of now removed top right fan, but in the hard load, it wasn't noticeable, actually natural, no air coming neither in nor out.

A number of things are happening from the fan you flipped:
-it's taking some of the air exhausted by the fan next to it and pushing it back into the case.
-it's pushing against the air coming up from that pass-through on the gpu cooler.
-it's intercepting some of the air coming in from the front.

I just moved the fan at the bottom, right under the GPU. I don't really feel any difference but the temperature of the GPU is now slightly lower as expected meanwhile the CPU temperature didn't have a difference (maybe it was a bit lower too).

Also this it look too obsessed if I ask this but do you think due to the way GPU's triple fans work, that would make any difference to move the bottom fan to the right empty block? atm I placed it at the left block assuming it's right under the GPU's chipset.

 

[USAFRet]

With all these fan changes, have you been keeping a log of measured temps?

 

[Phaaze88]

I just moved the fan at the bottom, right under the GPU. I don't really feel any difference but the temperature of the GPU is now slightly lower as expected meanwhile the CPU temperature didn't have a difference (maybe it was a bit lower too).

As USAFRet posted, are you even keeping logs? 'Cause most of this is pretty pointless if you aren't comparing the thermals of ALL your cooling devices in with each new fan orientation; can't see if any tradeoffs are happening or not.

Also, there's a large, cubed box of air resistance right below that fan, that's why barely anything changed. That spot is for fanless psus, or hybrid psus with 0rpm modes(load is low), to be able to ventilate upwards, since they would heat up if their grille was facing down.

 

[scout_03]

does all the fanss have same cfm values in the case also made sure your cpu front cooler fans push air in the fins and the back fans pull hot air out from it ti back you could use hwinfo to made a log of your test with voltages fans speed and temps .

 

[mahdimz]

does all the fanss have same cfm values in the case also made sure your cpu front cooler fans push air in the fins and the back fans pull hot air out from it ti back you could use hwinfo to made a log of your test with voltages fans speed and temps .

They're not exactly the same but won't be much difference. All of the fans are 120mm, 3 front fans have max 1300rpm and the rest have max 1700rpm.

As USAFRet posted, are you even keeping logs? 'Cause most of this is pretty pointless if you aren't comparing the thermals of ALL your cooling devices in with each new fan orientation; can't see if any tradeoffs are happening or not.

Also, there's a large, cubed box of air resistance right below that fan, that's why barely anything changed. That spot is for fanless psus, or hybrid psus with 0rpm modes(load is low), to be able to ventilate upwards, since they would heat up if their grille was facing down.

I had the logs but I actually delete, honestly didn't check them out well enough but after all, from what I remember the current fan management had slightly lower temperatures, especially for the GPU.
About the power supply, I actually thought about that decreasing the airflow of the fan but finally did put the fan there cuz it was right under the GPU's chip. Do you think that would make it better if I move it to the right empty block?

 

[USAFRet]

I had the logs but I actually delete, honestly didn't check them out well enough

Without actual numbers before and after, this is all just speculation.

 

[Phaaze88]

About the power supply, I actually thought about that decreasing the airflow of the fan but finally did put the fan there cuz it was right under the GPU's chip. Do you think that would make it better if I move it to the right empty block?

A little, but I wouldn't expect a miraculous improvement; there's psu cables down there, maybe you're using the HDD cage, and the air coming in makes like a 90 degree turn upwards.

 

[mahdimz]

A little, but I wouldn't expect a miraculous improvement; there's psu cables down there, maybe you're using the HDD cage, and the air coming in makes like a 90 degree turn upwards.

Then I'll just keep the current fan orientation, it's really a pain to unplug the GPU to unscrew the fan. But anyway I guess the current orientation is much better than the first one that I had.

Thanks for anyone who has helped!