I'm not trying to beat you up but you keep saying this like its a fact. When it's actually an opinion. You given no scientific evidence to show that is does not
Neither has anyone else. The diference is I'm University educated and have a great deal of experience in airflow design. However, I'm not willing to write a 4 page essay on the matter. The evidence is out there if you want to learn.
So here is a factual example that having more air being forced in with filters then is being sucked out the back will filter your air. So the majority of air will be as clean as the size of the filter. Yes he's a scientist.
If he adds exhaust fans to the top the presure in the case will drop and air will be pulled in from the back and everywhere else. Then that dust will increase but it will cool better. I rest my case, now I will go admire my dust free components.
Sorry, that video was all talk and no merit and did not help your position. They used a smoke machine in a VERY basic demonstration to show airflow through the front filter with & without front fans, nothing more. They did NOT show long-term dust build-up, nor comparative dust performance or thermal performance measurements in a positive VS negative pressure scenario. There was nothing in that video of any scientific value to this topic.
The misconceptions about positive & negative air pressure scenario's stem from the clean-room good practice models.
Learn the difference between negative pressure vs. positive pressure cleanrooms and discover how they can work for your application.
angstromtechnology.com
These kinds of clean room scenario's do not and can not apply to a PC case as the usage model is extremely different. The only way to prevent dust contamination in a PC case, or reduce it in any tangible manner, is to operate said PC inside a clean-room type environment. Dust contamination differences in common air environment electronics that need air-flow induced cooling is insignificant.
Dust is easily cleaned and is of minimal concern unless the user of a PC is either careless or lazy.
So the primary concern is, once again, cooling not dust. As there is no evidence to show that the differences between cooling effect between positive & negative air pressure in a PC case. The focus therefore needs to be on airflow. This is what the video effectively showed: Not that the filters were of any benefit, but that the addition of front mounted fans pulling air through that particular case created better airflow. It may not have been their intention, but is the result they proved. The filters actually inhibit airflow and as they collect large dust particles and become clogged, the airflow will dramatically diminish.
So once again, lose the air filters, add better fans and configure them for good airflow through your case, clean your system out every month or so(depending on how dusty your operating environment is) and enjoy!
But who cares, I'm GPU limited 99% of the time anyway. 
re read my post.
