This is an extremely well researched and presented video that exposes the fact that HEPA purifier marketing is a bit of a scam. The most important factor in air purifiers is not the filter but Clean Air Delivery Rate. You can only make a difference if you are moving air through the filters faster than particulate is introduced into the air.

I just returned a Medify filter because their advertised square footage is way higher than what the purifier should support based on the info in the video; it is inadequate. No idea how they are calculating their numbers - not to mention it's probably at the max speed setting - but it doesn't align with the sources from the video.

On top of that, smaller air purifiers must move air faster, be noisier, and the smallest sizes of particulate are captured most effectively at low velocities.

Use something like this to make a nicer version of a CR box: https://acinfinity.com/component-cooling/cabinet-fan-systems...

Or buy one of these: https://www.cleanairkits.com/

Those seem to be the best options that ACTUALLY work.