Positive Or Negative flow in terms of Dust accumulation?

[Ash Blake]

To my understanding, dust accumulates through the cracks in the chasis in a negative flow, and dust comes in through the intakes mainly.

But I do not understand how more dust is coming in through the cracks than intake fans for negative and positive respectively.

If the surface area of intake fan areas is greater than small cracks in the chasis, how is more dust coming in through the cracks?

 

[Thineswar]

think of it like this:
in a pc case, you either have:
a) positive air pressure
-here you have more air inside the case than outside; this is achieved by having more intake fans than exhaust. as a result, air tries to push itself out through the small nooks and crannies of the case.
- pros: less dust buildup in your system
-cons: hot air takes a longer time before it could be expelled from the pc, meaning that your components will be running hotter.

b) negative air pressure
-in this scenario, you have less air inside than outside, meaning you have more exhaust fans than intake. this will cause the air from the surrounding area to push itself in through the nooks and crannies of the case.
-pros: heat from the components is removed almost immediately
-cons: dust builds faster inside the case

c) neutral air pressure
-this means that there is the same amount of air pressure both inside and outside the case. this is made possible by having the same number of intake and exhaust fans.
-pros: not very clear, because
-cons: very difficult to achieve as the surrounding air pressure is constantly changing throughout the day.


if all of this is too much to read, then try watching these
[video="https://www.youtube.com/watch?v=4NYHC3DXynM"][/video]

[video="https://www.youtube.com/watch?v=g8EN3K-eaVA"][/video]

[video="https://www.youtube.com/watch?v=sh6F2eccMec"][/video]