Air flow vs. static pressure

i am getting the h440 from nzxt and there is some serious choking of the 6 120mm fans. i was wondering if it would be better to get 6 static press fans or 6 air flow fans. the top three will be exhaust and the front 3 will be intake

iInce you're using intake and outlet fans, you shouldn't worry about static pressure if you're not using radiators with very dense grids. If the influx and output is balanced, air will flow. Static pressure fans are typical for use on dense radiators, where the radiator works as a diffuser for the output. They usually are counter-productive as regular case fans because the directed airflow causes two things: hotspots inside the case, and more noise inside the case. Usually static pressure fans also move less air volume per minute than regular fans.

Some people use static pressure fans behind intake dust filters, because they think the dust filters choke the fans. That is just not true. The impedance causes by most regularly cleaned dust filters is pretty negligible. There are only so much air molecules, fans don't create air, they just make molecules move. And those molecules want to stay together in a given density. Your output fans will output air, the air molecules will have to follow, the air will have to be taken in, the suction of a balanced output fan arrangement will assist the intake fans to perform within spec just because of the kinetic energy of the air volume. If your system isn't balanced, what you typically see, is dust trails around small openings in the case, like the side panel corners etc... That tells you that the input fans can't keep up with the output fans, which is something that is often seen in systems, because people tend to think output fans are more important than input fans, and to a certain degree, that's also true. It's not necessarily a bad thing for cooling, but you'll get dust in your case. Sometimes cranking fans up gives worse cooling, depending on the arrangement. Faster airflow doesn't always mean better cooling. The most important thing is constant airflow throughout the case. The ideal is a quasi laminar airflow, typical of stack-type cases, where the air moves entirely horizontally through "wind tunnels" with equal input and output fans. A laminar airflow has very low turbulence, which avoids hotspots, noise and dust settlement. It's easier to achieve a quasi laminar airflow with slower spinning fans. In such arrangements, you can hardly feel the airflow blowing on your hand or face close to the output fans or input fans, but the overall Bernouilli effect around the case, not in front of the fans, will be considerable after a while, it will make the entire air volume in the room move, and you'll feel the draft when you're sitting some distance away from your case, rather than right in front of the fans.

3x120mm in and 3x120mm out is quite a good arrangement for a high performance system. I wouldn't worry too much about it. Nzxt are generally pretty good cases when it comes to airflow.

there are 3 120 mm in the front, three on the top, and 1 140mm in the rear. i have no radiators. should i use all air flow optimized fans even if they are seriously choked?