If these 5 little fans do the job as well as a full size box fan, I have to wonder:

1. Are box fans just really terrible? I would expect the amount of airflow from a box fan to absolutely demolish these little case fans.

2. Does airflow not actually matter that much? Assuming the box fan really does move far more air, that would imply that air filtration is somehow not driven by air flow. Or else the testing methodology is flawed.