I’ve lost track of it, but there was a study published about this style of filter around the start of the pandemic that suggested it could be effective at reducing PM2.5 and possibly airborne virii. It’s a sound idea conceptually – continuously filtering and re-filtering room air at a high volume is how industrial clean rooms work, and while this is a far cry from a carefully-engineered system like that (you won’t have the hygienic surfaces and laminar flow characteristics, for instance), it at least has more than enough airflow to filter a room effectively.