Shopping for a case fan isn’t exactly glamorous, but not all fans are created equal. They come in different sizes, some light up with LEDs, and some support pulse width modulation (PWM) so that you or your system can control the speed. Most of the options are straightforward, though if you’re wondering what a high-static pressure fan is and why you might want it, you’ve come to the right place.
There are typically two main types of fans you’ll see advertised. One is high airflow, and these are rated by the amount of air they’re capable of blowing at full blast. This is usually measured in cubic feet per minute (CFM). The faster one of these fans spin, the more airflow it’s capable of. However, larger size fans don’t have to spin as fast to move the same amount of air as smaller fans, which is good to keep in mind for noise management. Big or small, these are appropriate for open spaces where there aren’t any obstructions.
The other is high-pressure static fans, which are best used on radiators, CPU and GPU coolers, in front of hard drives, and other places where airflow might otherwise be blocked by an object. They’re designed for restrictive spaces and typically have a high CFM rating to account for the blockage. This allows them to push (or pull) air through the heatsink or other object. Simply put, their job is to overpower obstructions with sheer force.
Even though high-pressure static fans are more forceful than high airflow fans, they’re not necessarily loud. Manufacturers use specially designed fan blades to focus air without creating a ruckus. Corsair, for example, sells “Quiet Edition” high-static pressure fans. Set on low, these fans runs at 1,450 RPM and push 37.85 CFM while producing just 23 dBA. At high, they run at 2,350 RPM and push nearly twice as much air at 62.74 CFM, and produce 35 dBA—that’s about the noise level in a library.