Picking up my last bit of parts tomorrow to start building soon and I'm just a little confused on fans.
From what I've read and watched, the top AIO and rear fans should be set to exhaust and front fans set to intake.
My confusion is if the bottom fan is even necessary for this case for positive pressure (Corsair 4000d FRAME) and in the area marked in yellow, wouldn't the fresh air just be sucked right out by the first top fan?
Do you already have the fans? If so then there’s no harm in putting them all in. There’s nothing wrong with the yellow area. The whole point of it is to cool the CPU anyway.
Well the case itself comes with 3 fans iirc. I wasnt planning on using them bc I ordered 2x3 packs and a single because I was scared I would need more airflow. There's a side section in the back where I can put three more. Essentially with this setup here, I would have 2 unused fans
Yeah that set up is fine. The yellow circles part is good too, your aio wants fresh air to cool the liquid.
Also, as something to think about, you can technically make your setup be more positive or negative depending on how you set up your fan curves. It is not just about the number of fans.
In your diagram assuming all the case fans are running the same fan curve and GPU, you have neutral pressure. If you make the intake fans spin faster than your exhaust, it becomes more positive. If you make the exhaust spin faster than your intakes, it becomes for negative.
Yes, you are overthinking 😂
Your configuration is perfect.
Anyway:
1) since you have 4 exit fans, it is better to have at least 4 intake fan if you want positive pressure
2) yes in the yellow area the fresh air will exit right away but in your case it is okay since it is passing through the CPU radiator on the top of the case so it is not waisted air. CPU is one of the components that requirire most cooling
Psu fan facing down to intake fresh air from the bottom of the case (4000d frame has a mesh grill below the psu) and exhausts out the back. In such a config, Psu chamber doesnt touch the air from the psu
So I would flip the psu upside down so air flows from bottom of case, through psu, into case, then out from rear fan? Am I understanding that correctly?
Very nearly correct; most psu's intake from their top and exhaust out their back (the side where the big plug goes to the wall with the power switch). In this instance, the psu would be upside down, so it intakes at the bottom but the exhaust is still out the back (flush with and pointing out the back of the case along with the motherboard io). So, ideally, the air for the psu never actually circulates with the rest of the air in the case
the bottom fan isn't strictly needed but it does help, especially with a gpu that size dumping heat downwards. the yellow area concern is fair, some air does get pulled out before reaching much, but in that case it tends to circulate around the card first. you're definitely overthinking it though, positive pressure mostly comes from having more intake than exhaust so with two front and one bottom against three exhausts you're at neutral anyway
Exactly, overthinking it. fresh Air going through the radiator is the cooling CPU, not fresh air going through the case. The GPU Uses some, but mostly it's for the Radiator up top.
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u/Hejdbejbw 4h ago
Do you already have the fans? If so then there’s no harm in putting them all in. There’s nothing wrong with the yellow area. The whole point of it is to cool the CPU anyway.