Question Should i use spare fan as Case Exhaust or CPU Cooler Exhaust

[Phil Holm]

So ive been thinking about getting the antec df700, which comes 4 fans(3 front intake, 1 rear exhaust) + 1 reverse fan thats put on top of the psu shroud, which seems to not make any difference in temps according to reviews. So ive been thinking of using that spare fan as a top exhaust instead, even tho it wont look that pretty being a reverse fan.

Then i heard cpu coolers ideally should have 2 fans(intake/exhaust), im (planning on) buying a somewhat cheap cpu cooler (Xigmatek Air Killer) which only has 1 fan, I thought it might be a better idea to use that spare fan as a cpu cooler's exhaust. Which option is better? Is a cpu exhaust fan even necessary? Or should i buy another fan to put on both cpu and case exhaust?

 

[USAFRet]

Exhaust on the case.

Push/pull on the CPU cooler generally makes little benefit.

 

[Lafong]

CPU cooler exhaust....I assume you mean on the back side of the cooler, so that the cooler has a fan on each side.

That can help, but it doesn't help as much as you might think...under 5 degrees going from memory in normal circumstances.

I'd start with a total of 3 fans:

front of case intake, rear of case exhaust, and 1 on the cooler.

Evaluate temps and adjust if necessary.

 

[Phil Holm]

Exhaust on the case.

Push/pull on the CPU cooler generally makes little benefit.

I see. Also im really surprised, it took 1 minute to get my answer, normally have to wait like a day on other websites. Thank you.

 

[Phil Holm]

CPU cooler exhaust....I assume you mean on the back side of the cooler, so that the cooler has a fan on each side.

That can help, but it doesn't help as much as you might think...under 5 degrees going from memory in normal circumstances.

I'd start with a total of 3 fans:

front of case intake, rear of case exhaust, and 1 on the cooler.

Evaluate temps and adjust if necessary.

Does going from 3 intake/1 exhaust to 3 intake/2 exhaust make a good difference?

 

[USAFRet]

I see. Also im really surprised, it took 1 minute to get my answer, normally have to wait like a day on other websites. Thank you.

You're welcome. We aim to please...😉

 

[USAFRet]

Does going from 3 intake/1 exhaust to 3 intake/2 exhaust make a good difference?

Possibly, probably, maybe.

Case fans have but one function.
Move air through the case. In the front, out the back/top.

The only way to know is to document the temps before and after.

 

[Lafong]

Does going from 3 intake/1 exhaust to 3 intake/2 exhaust make a good difference?

I very rarely hear about 2 exhaust on the back of a case.

Sometimes one at the back and one on top.

I rarely have used a top exhaust, but my PCs don't generate a lot of heat.

You can and should experiment, particularly if you are crowding temperatures by overclocking or extreme loads or high ambient or poor CPU cooler, etc.

In my experience "good differences" are usually due to the CPU cooler, the front intake, and the single rear exhaust. Anything else is at the margins and less significant....

But there are people who would consider a 2 degree improvement to be a major accomplishment and worth spending 100 bucks and 10 hours to arrive at.

To give you a for instance:

My PC normally idles in the low 30s.

Just for laughs, I once disconnected all fans other than the single CPU fan, as an experiment. Idle temp went up to about 50....nowhere near a problem level. I think I was using a Noctua U12S cooler at the time...a very good cooler in its class, but not extravagant.