Well with that said I’m surprised you haven’t re-wired your VFD fan to only come on when it heats up…
You are either mad or have too much time on your hands 
I gave up on trying to cut the noise out. Now I just wear noise cancelling headphones - after you have a compressor, VFD and spindle going it’s the only way to win a loosing battle, other than locking everything in a cupboard…