My PC has only the basic 2 front intake fans and 1 rear exhaust fan. There are space for 2 more at the top and I'm considering whether it's worth installing more fans when I upgrade to some hotter components, but my research is giving me conflicting information.
To be clear, I'm not asking "whether I really need more cooling", as I believe that is too opinion-based and subjective. Rather I'm asking whether there is a way of configuring more fans that would provide more cooling (regardless of whether I "need" more cooling). And especially I'm after objective explanations of how the conflicting principles I've found in my research should be assessed against each other, in the hope that I will learn how to assess similar decisions in future; I don't just want opinions about what the "best" principle to follow is without some explanation of why that one trumps all of the other concerns.
Here's what I've got currently:
(The case is a Corsair Carbide 540 Air, so the PSU and drives are in a separate compartment at the back of this picture, out of the main air flow)
Here are my concerns:
The general advice seems to be that top fans should be exhausts, on the principle that heat rises. However adding 2 exhausts would create negative pressure, which I would like to avoid.
Currently there is the nice clear air flow from the front intake through the CPU heatsink fan and out the exhaust (there's obviously hot air coming up from the GPU as well that has to merge with this, so the picture is more complicated than my nice arrow). Some of my research has suggested the option of turning the rear fan around to be an intake and then adding exhaust fans to the top, but this seems like it could risk turbulence from the rear intake fan blowing directly against the CPU heatsink fan. In fact, would adding any airflow from the top fans risk be counterproductive by disrupting that clear front-to-back flow?
That same current flow almost suggests that if I was going to mount fans, an exhaust at the top-front would be counterproductive (it would mostly remove cool air that's just come in from the front-top fan), and an intake at the top-rear would be counterproductive (it would just add cool air to the region where I'm channelling all the hot air for exhaust out the rear fan. This almost suggests I could do one intake and one exhaust on top, but I gather that risks just creating a circular flow between the two adjacent fans blowing in opposite directions (pulling hot air from the exhaust back into the case).
So then the options I'm considering (in no particular order) are:
- Add one intake at the top-front, and one exhaust at the top-rear.
- Just add an intake at the top-front.
- Just add an exhaust at the top-rear.
- Turn the rear fan around so it's an intake, and add 2 exhaust fans to the top.
- Do nothing, if the top fans would only be counterproductive or marginal for the overall cooling of this system.
But I don't know how the various concerns should be weighted against one another to come up with a decision. If it's possible to reason out which option is likely to be work the best, then I'd like to know both (a) what it is (or some none-of-the-above option) and (b) what the reasoning is that leads to that conclusion.
Obviously once I've bought the fans I can monitor temperatures and do some experiments, but if general principles strongly suggest one particular option (especially the do-nothing one) then I'd rather start from there.