If you want to move air quietly you need to move a large volume slowly.
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I've been looking for a fan that literally mechanically raises and lowers a large leaf-like thing (think Anthony&Cleo) in a pleasant wafting fashion. How does no such device exist?
I've seen that done. But only in commercial contexts, like restaurants, or in Thailand and India
Vornado makes powerful fans. I think they're pretty quiet on low and medium, less so on high, but YMMV depending on your noise tolerance. I haven't tried Dyson but they are outrageously expensive (and I think I've seen a video on them not moving much air, I'll come back with the link if I can find it).
Edit: video
How about a 20" box fan on low? Too loud? Put together several computer case fans, they're made to be quiet.
Either of these fans can also be used to make a Corsi-Rosenthal box to filter air. So you could do both...assuming it's not too loud...