Where should I put my case fan?

[da na]

Retro build, old case with barely any airflow, you know the drill.

Could either put a 60mm case fan on the front or rear. Which would be best? Rear is right behind the CPU heatsink fan so I think it's less necessary there since all it's doing is blowing a little extra CPU heat out. In the front it's bringing air in. I do have a blower GPU though and those are good for negative pressure right? 

(What I'm cooling is a HD 5870 and Q9550. About 300w total)
Which do you recommend? 

[IkeaGnome]

I'd start with the front, but it should be easy enough to set it up on the front for a couple days then move to the rear to see temperature difference yeah? 

[Benito593]

I would think you would need more fresh air coming in. So, I would say the front.

[An0maly_76]

I remember a thread awhile back that someone had stuffed some hardware into a case that wasn't really designed for it or something -- had a front grille pattern of holes in the skeleton that they wished to open the case to in order to better ventilate. I suggested copying that grille pattern to a piece of paper or cardboard, then transferring that pattern to the case  and drilling the holes slowly, letting the bit heat up and help to melt its way through.

 

That being said, heat does rise, so perhaps do something similar in the top of the case with a couple fans hung beneath?

Edited April 15, 2022 by An0maly_76
Revised, more info

[Kid.Lazer]

Is putting a fan in both spots not an option?

For good airflow with a blower GPU, I'd (personally) want the the case to have equal intake and exhaust. The GPU counts as an exhaust, so an intake would be preferred if that's the only option. Not knowing what the rest of the system looks like is hard though. If the PSU is also acting as a rear top exhaust (common in old cases), then more intake is a top priority.

[da na]

5 minutes ago, Kid.Lazer said:

Is putting a fan in both spots not an option?

For good airflow with a blower GPU, I'd (personally) want the the case to have equal intake and exhaust. The GPU counts as an exhaust, so an intake would be preferred if that's the only option. Not knowing what the rest of the system looks like is hard though. If the PSU is also acting as a rear top exhaust (common in old cases), then more intake is a top priority.

Unfortunately can't do both. Not willing to spend on a fan splitter for this build that won't be frequently used or pushed to its limits and I'm out of headers. Yes, PSU on top.