They look better than DIYs, are typically quieter for the same cfm, and optionally have an automatic mode where the fan speed changes based on the detected air

They look better than DIYs, are typically quieter for the same cfm, and optionally have an automatic mode where the fan speed changes based on the detected air quality. But yeah if you don't care how they look or how noisy they are just assemble one yourself and blast it on max. That's what I did for two years in China and it worked (had a separate particle counter to measure PM).