Do I need an extra ntake or exhaust fan to create positive air pressure for my system?

[sapped]

Hey guys,


I’m thinking of adding more fans to my system, to cool my GPU and more importantly in controlling the amount of dust getting in to my pc case. Thus I’m hoping to set up a positive air pressure with more intake airflow than exhaust.


However I am confused with the following, because I’m using the massive Noctua NH-D15 CPU Cooler to cool my processor, it has two 140mm fans attached on top of the heatsink like this:


http://noctua.at/en/nh-d15.html


So I have a total of 4 fans (140mm) in my system, 1 intake in the front, 1 exhaust in the back, and 2 fans in between attached to my heatsink. What I’m wondering is, because I’m hoping to create the positive air pressure, does the 2 fans attached to my heatsink count as intake or exhaust?


I can’t find any definite info on this, I remember reading an article stating the CPU fans also affects the air pressure. So I’m hoping to ask you guys, do I need an extra intake or exhaust fan in my situation, to create this positive air pressure I’m hoping to achieve?


Thank you so much for reading and I appreciate your responses!

 

[Valantar]

As your cpu fans are not connected to the sides of the case, they are neither intakes nor exhausts. However, if they are positioned so that they either pull in air from a large opening or push it towards one, they might affect case pressure somewhat. Where is your front intake fan placed? Is the cpu fan blowing straight at the rear exhaust?

 

[sapped]

Ahh thank you so much for your help mate, appreciate it!

 

[Valantar]

No problem

What case is your build in? And where is your front intake fan positioned?

In general, having one more intake than exhaust is a decent idea - not necessarily required, but it gives you positive pressure and plenty of fresh air to both CPU and GPU, even if you slow down the intakes to reduce noise. I'd say it's a decent idea, although, again, it's probably not necessary.

 

[sapped]

I'm using an Fractal Design Define R5, with dust filter in the front and bottom.

Just a question though, if I put the new intake fan in the bottom, does it suck in more dust than usual even with the filter?

 

[Valantar]

I'm using an Fractal Design Define R5, with dust filter in the front and bottom.

Just a question though, if I put the new intake fan in the bottom, does it suck in more dust than usual even with the filter?

Yeah, it would. If the filters are the same as in my R4, they're not the best, and fine-grained dust gets in no matter what you do. The front is easier to clean, quieter, and doesn't act as a vacuum cleaner.