[SOLVED] Should I add a top rear exhaust fan?

[Assaf Patishi]

Hi,
I have a pretty standard setup with 3 (120mm) intake fans at the front and one rear exhaust fan, the case is Phanteks p400a.
I have i9 10900k with noctua NH-U12A cooler and the idle cpu temps are very good, around 26-30c depending on the room temp (usually 21-24c with air conditioner).
But on load they jump to 80-90 pretty fast.. and I notice that it takes a few minutes for the cpu to return to its original (30'ish) temps when the load is over.. I wonder if that's because the single rear fan isn't capable of exhausting the hot air fast enough.
I also want to know, with a straight front to back air path like I have, what is exactly the logic of adding a top exhaust fan, I mean..the cpu cooler is pushing the air towards the rear fan pretty aggressively, so by adding a top exhaust fan, wouldn't it be "disrupting" the air direction?

Thx.

 

[CountMike]

Hi,
I have a pretty standard setup with 3 (120mm) intake fans at the front and one rear exhaust fan, the case is Phanteks p400a.
I have i9 10900k with noctua NH-U12A cooler and the idle cpu temps are very good, around 26-30c depending on the room temp (usually 21-24c with air conditioner).
But on load they jump to 80-90 pretty fast.. and I notice that it takes a few minutes for the cpu to return to its original (30'ish) temps when the load is over.. I wonder if that's because the single rear fan isn't capable of exhausting the hot air fast enough.
I also want to know, with a straight front to back air path like I have, what is exactly the logic of adding a top exhaust fan, I mean..the cpu cooler is pushing the air towards the rear fan pretty aggressively, so by adding a top exhaust fan, wouldn't it be "disrupting" the air direction?

Thx.

Yes, there should be about equal intake and exhaust for best air flow Just see if fan could be placed behind CPU cooler. That single fan just at back can actually slow CPU fan's flow if it's capacity is lower.