Optimal Case Fan Setup?

[Coffee [Cappuccino]]

Hi guys,

I currently have a Corsair Air 240 case with a Micro ATX motherboard and was wondering if my current fan setup is optimal for sufficient airflow throughout the case. The case has a dual chamber design meaning that the power supply, HDD, SDD, and cables are placed in the back of the case thus leaving a lot of space in the front for airflow. At the time being, I have 2 (120mm) intake fans on the front and 2 (120mm) exhaust fans on the top (none on the back as it only fits 80mm fans and they're notorious for being loud). My concern is that the top intake fan (fan no. 1) will take in cool air but the moment the cool air goes inside the case, the top exhaust fan (fan no. 3) will immediately take it out preventing the cool air from properly circulating the case. Any suggestions on whether my theory is true? 

Also, another concern I have is that the front intake fans are covered by a metal mesh (pretty standard with most cases nowadays to prevent/reduce dust intake). Although the mesh isn't super thick to the point that it completely blocks the airflow, it does show some sign of impedance. I tested it by placing my hand inside the case with the mesh and without the mesh and the airflow seemed much greater without the mesh attached. Should I be using an airflow optimised fan or should I be using a static pressure fan because I know they're great at going through tight spaces?

Drawing of the Fan Placement (Please Look)
https://imgur.com/a/BWu6e

Link to the case:
https://www.corsair.com/us/en/Categories/Products/Cases...

My build
Case: Corsair Air 240
Motherboard: ASRock AB350M PRO4
CPU: AMD Ryzen 5 1400
GPU: Zotac GeForce GTX 1060 6GB AMP! Edition
RAM: 8GB HyperX Fury (2x 4GB) 2133 Mhz
PSU: Cooler Master MasterWatt Lite 500W
SSD: Sandisk 240GB & Intel 545s 256GB 
HDD: Seagate Barracuda 1TB

P.S. The 2 intake fans are the bequiet! Silent Wings 3 and the 2 exhaust fans are the Corsair AF120 Quiet Edition.

Sorry for the long post.
Kind Regards,

Coffee [Cappucinno]

[WoodenMarker]

Obstructions including mesh lowers airflow substantially for most fans. Having more static pressure would help but that's generally at the cost of more noise whether it's by using a different fan design or raising the rpm.

Air from the front fans spread out into the case before being exhausted and so the top fan probably promotes airflow more it exhausts the cool, unused air out. You'll probably need to test with and without that top exhaust fan to find out.

[Rhoban]

Well, you could remove the mesh, but that means more dust into the system. If you don't mind the dust or cleaning it regularly (like every week), then go ahead. 

 

The only other thing you can do is to Rev up the front fans. More rotations equals more airflow. 

By increasing the intake fan rpm you could make it have the same airflow as if there were no mesh. 

Of course, this may also mean they will be louder. 

 

Another problem is that your exhaust fans have only half the cfm of the intake fans. That makes for a very high positive pressure inside the case. In other words, more air goes in than it goes out. This cause air to become stagnant, heat up and increase temperatures. 

I know positive pressure is preferred (due to dust), but in my opinion, it shouldn't be that much. 

 

Negative pressure creates a somewhat better airflow inside the case, but it also pulls more dust inside too. Also, the temperature differences aren't that big between positive and negative. But it depends on the case. 

 

I would say try to have a near neutral pressure in the case. Either slightly positive or slightly negative. Yours is currently predominantly positive. 

To do this, have the exhaust run at 100% and the intake at 50%. That's about slightly positive 

[JoostinOnline]

8 minutes ago, Rhoban said:

Well, you could remove the mesh, but that means more dust into the system. If you don't mind the dust or cleaning it regularly (like every week), then go ahead. 

That depends entirely on where you live. Some places don't get dusty.

[Rhoban]

4 minutes ago, JoostinOnline said:

That depends entirely on where you live. Some places don't get dusty.

Dust is everywhere, but in different quantities. 

 

Regardless of where he lives, dust will get into the system anyway. If it's a less dusty area, then all it means he would have to clean it less. 

[JoostinOnline]

1 hour ago, Rhoban said:

Dust is everywhere, but in different quantities. 

 

Regardless of where he lives, dust will get into the system anyway. If it's a less dusty area, then all it means he would have to clean it less. 

I think you knew that's what I meant. It's very unlikely that he'll ever have to clean it weekly.