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: 

https://drive.google.com/drive/folders/12mkNoaHBySbqeCwcTWhB2y3quVBViPBS?usp=sharing