[bipson]

I have one of those.

It does not "wash" the air. It has a HEPA-filter on the intake side before the humidifying cycle. So it is basically the same thing as all other examples on this comment page.

You can actually run it without water (which we do), then it does only filtration.

Don't buy this particular product. It is overprized and has dramatic production quality issues (we sent two back, amazon reviews indicate larger issues).