Excellent study looking at the practical implications and durability of performance of portable air cleaners in classrooms in Germany. Several important lessons to be learned https://doi.org/10.1080/02786826.2022.2147414
@cleanairstars Regarding use of multiple air cleaners: a single Noctua NF-A14 5V fan paired with proportionally sized HEPA or MERV-13 filter, should be able to provide ASHRAE's recommended EOAi (for a single person.) A multiple of these, naturally dispersed when powered by [student] phones/laptops facilitates quieter (24.6 dBA), homogeneous air mixing. A 12V power distribution network at ceiling for similar suspended or mounted (fixed) 140mm fan air cleaners follows same principles.
@cleanairstars I have not. (I passed on material to brother who ignored it.) Maybe Rob Wissman tested a HEPA filter once upon a time, but you're about the only link to information since I left Twitter. I'd be curious about MERV-14 as well. Indian fellow I believe (forget name) had posted a study of California school(?) comparing, but may have been in-duct filter. The Noctua NF-A14 iPPC-3000 PWM has a much higher static pressure by comparison.