Just for reference, and if anybody else wondering when getting your spanking new AX40 and found that everything in the documentation is in Korean.
Buttons from left to right:
First four is touch buttons: On/off; Speed selection; VirusDoctor On/off (single touch) + filter change reset (hold a few secs); Child lock (hold a few secs)
Last four is speed indicator: Auto; High; Low; Sleep
Lights on the On/off touch button also functions as air quality indicator: blue, green, yellow, red (something like that)
VirusDoctor is Samsung's fancy name for ionizer function, default is OFF.
Just full blast all the way, can't hear a single thing