I'm planning a setup with three front fans bringing air into the case, three top-mounted fans attached to an AIO radiator exhausting air, and one rear fan exhausting air. I'm concerned this may create negative pressure. Would it be better to aim for balanced or slightly positive pressure, and are there any changes you would recommend for fan placement or speed? I'll be using the same model of fan throughout the build.
2 Answers
Slightly positive pressure is generally preferable because it can reduce dust entering through unfiltered gaps, but the difference is usually modest. Fan curves let you adjust the balance either way. I wouldn’t overthink the pressure issue—install the fans in the planned positions, monitor CPU and GPU temperatures, and change the curves only if temperatures or noise are higher than expected.
Your proposed layout is perfectly workable, and negative pressure is not dangerous. The main downside is that unfiltered air can enter through gaps in the case, which may increase dust buildup. Since the front intake fans are filtered while the top exhaust fans may not be, you could remove the rear exhaust fan or use fan curves to keep the intake fans running somewhat faster than the exhaust fans. With identical fans, having the top fans operate around 75% of the front fans’ speed should help maintain slightly positive pressure.
Would it make sense to set one of the AIO fans near the front as an intake and leave the other as exhaust? That might let fresh air reach the motherboard more directly while also giving the case more intake airflow.