Air dust removal?

[Mr Pounder Esquire]

As in the curtain in my office that gets blasted with dust spewed out from the tower system.

[PeterC]

That's because dust has a (un)natural equlibrium. Removing dust causes an imbalance in the dustiverse and so more will slide down to fill the inadequate volume. The universe isn't infinite but the dustiverse is.

Actually, astrophyscisists can't find most of the matter in the universe - I think that I've just explained it.