Case Fan buying order for OBS recording: must-have, nice-to-have and skip

Case fans set the airflow and noise of the whole build, and choosing the right fan type for each spot beats simply buying the highest RPM on the shelf.

Quick Answer

For OBS recording, a set of quality 120mm or 140mm PWM fans in a balanced intake-heavy layout is the right move, with a six-fan set often landing near R1,500. Favour airflow-optimised fans for intakes and static-pressure fans behind filters or radiators.

Airflow Versus Static Pressure

Open intakes want high-airflow fans, while fans pulling through a dust filter or a radiator want static-pressure designs to push past the resistance. For OBS recording, mixing the right type in the right spot matters more than raw RPM. A 140mm fan held near 1000 RPM often beats a 120mm one screaming at 1800 RPM for both noise and effective airflow.

Layout And Positive Pressure

Run slightly more intake than exhaust so the case holds positive pressure, which forces dust in through the filters rather than every gap. A typical clean layout is two or three front intakes feeding a top and rear exhaust. Keep the air path clear from front to back so cool air actually reaches the GPU and CPU.

Noise, PWM And Bearings

PWM fans let the motherboard ramp speed with temperature, staying quiet at idle and only spinning up under load, which is ideal for OBS recording. Fluid-dynamic or magnetic-bearing fans last longer and run quieter than sleeve bearings. Anti-vibration mounts stop the low hum that cheap fans transmit into the chassis.

FAQ

How many case fans do I need?

Two or three intakes plus a rear and optional top exhaust suits most mid-towers. The goal is a clear front-to-back air path with slightly more intake than exhaust for positive pressure.

Should I run positive or negative pressure?

Slightly positive pressure is best: more intake than exhaust forces dust in through the filters instead of every crack, keeping the inside cleaner and easier to maintain.

Are PWM fans worth it over fixed-speed?

Yes. PWM fans ramp with temperature, staying near-silent at idle and only spinning up under load. Fixed-speed fans either run loud all the time or under-cool when you need them most.