You're right, thanks for the clarification, this is a "DIY air purifier" not a "HEPA" filter. (Apparently products today even have to clarify if they are "true

You're right, thanks for the clarification, this is a "DIY air purifier" not a "HEPA" filter. (Apparently products today even have to clarify if they are "true HEPA" due to misleading marketing) According to this website (https://freshairaustralia.blogspot.com/2020/01/how-does-merv-13-filter-compare-to-hepa.html https://freshairaustralia.blogspot.com/2020/01/how-does-merv...) a study for underground mining filtration found a MERV-16 filter superior to HEPA in terms of airflow and cost, with a negligible difference in filtration efficiency. According to the study, the MERV-16 filters have higher flow rates than a HEPA filter, which would both make the MERV filter a better fit for an inefficient fan, and increase the air filtration rate. The author of that site also finds that the airflow rate can be more important than a filter's rated efficiency: https://freshairaustralia.blogspot.com/2020/01/why-air-flow-matters-more-than-filter.html https://freshairaustralia.blogspot.com/2020/01/why-air-flow-... After some web searching, it seems you can buy smaller replacement HEPA filters and MERV-16 filters starting at ~$40. So I guess you can spend less if you only need "air purifying", and more if you want the real deal.