Need help with CPU fan placement and direction

[martin.carline]

I have a Noctua NH-U14S and it was installed by my local PC shop. I am now looking to upgrade to a 1156 socket and i5 8600k and I am doing this myself for the first time.

Currently the shop has my one Noctua fan on the left hand side of the CPU radiator, so nearest to the exhaust fan. However, my exhaust fan isn't working and he said I didn't need to replace it as the Noctua fan was working as the exhaust fan so doesn't matter.

The Noctua fan sits within an inch or two of the broken exhaust fan.

What I would like to know is if this is correct and should I copy this setup when I install new motherboard and CPU?

Do I need to replace the broken exhaust fan and move the Noctua fan to the other side with airflow pointing at the CPU and exhaust?

Please also note that my PC case doesn't have any intake fans at the front either. I am considering a new PC case soon, but not having any problems with my overclocking i7 875k and temps.

 

[martin.carline]

Sorry, meant 1151 socket

 

[shmoochie]

I can't imagine that your i5-8600K is going to stay cool enough with no case airflow. But yes, that orientation is necessary to expel the hot air coming directly off the cpu heatsink since there is no case airflow. If you aren't going to get a replacement for the exhaust, then you might consider taking it out because it is just blocking your cpu fan now.

 

[martin.carline]

I can't imagine that your i5-8600K is going to stay cool enough with no case airflow. But yes, that orientation is necessary to expel the hot air coming directly off the cpu heatsink since there is no case airflow. If you aren't going to get a replacement for the exhaust, then you might consider taking it out because it is just blocking your cpu fan now.

Thanks for taking the time to reply. In the meantime I came across quite a few posts about whether or not you should have the CPU fan pushing air at the heatsink, or pulling it away from it (what I currently have). A lot were in disagreement about this, but overall it appeared that it was better to have your CPU pushing air at the heatsink.

I don't have any problems with cooling my i7 875k right now, but I suppose I could test this theory in my current setup to see if there is any difference in temps. That way I will know what to do when the i5 8600k goes in.

I will remove the broken exhaust fan as per your recommendation, and then maybe look at a new PC case very soon. Probably leave the overclocking until I have better airflow

 

[shmoochie]

I think the pull configuration is going to be more efficient for your setup since it puts the cpu fan closer to the exhaust and because it is the only thing expelling hot air from your case. Right now, the cpu fan is creating negative pressure in your case which pulls ambient cool air in across your mobo. I would be worried about the push config not creating as much negative pressure in the case since it is farther away from the exhaust and because the heatsink will be blocking it to a certain extent.

 

[martin.carline]

I think the pull configuration is going to be more efficient for your setup since it puts the cpu fan closer to the exhaust and because it is the only thing expelling hot air from your case. Right now, the cpu fan is creating negative pressure in your case which pulls ambient cool air in across your mobo. I would be worried about the push config not creating as much negative pressure in the case since it is farther away from the exhaust and because the heatsink will be blocking it to a certain extent.

Yeah, I can certainly see the dilemma. If I were to put a new exhaust fan in, would it then make sense to put the fan on the other side of the heatsink?

 

[shmoochie]

Yes, that would probably provide more consistent cooling for the whole pc. Coffee lake processors run pretty hot, and it might let you oc it a little. You can always transfer the exhaust fan into the new case when you get one.