I am also working on a very large extremely quiet air filtration appliance, using an extremely quiet quite big fan (500 mm blade diameter, 520 mm square frame) I have designed, and continue to improve.  This is the google folder for cad files etc, related things such as the SDP810-125A based micromanometer code are also here, this has been merged with the fan itsself, everything is in the one repository now: 

https://github.com/adouglas89/Big-quiet-air-purifier

UVC Nukit torch mod for external power/constant operation:

https://docs.google.com/document/d/1BQh_6jLaWd9nHVWsMZghqf-FgCTMaG_XzB_kwg550y4/edit?tab=t.0