Product review (1 stars): Swear By, Swear At
I used to swear by Venta Airwashers.  Now I swear _at_ them.  I owned one of their first models, the kind that plugged directly into the household outlet without using the "wall wart" transformer used by the new models.  The old version served me well for years, with only an occasional replacement of the clutch and the coupling between the clutch and the disk unit.  Eventually (after about fifteen years), the motor simply gave out...I suppose because of too much dust sucked into the works by the airflow.

The new version -- with the wall wart -- is a fright.  The motor is weak, so is the humidity output, and for some reason Venta has decided to make the new units "idiot proof" (which wasn't necessary: an obvious case of a solution in search of a problem) by adding a "turn off when no water" feature, which requires that passive electrical contacts run up the sides of the water tank and link with contacts in the cover.  All well and good, unless there is a little corrosion or lime deposite that breaks the contact (and if you have hard water, there is plenty of both).  From that undependable juncture, the ribbonlike, electrical linkage runs up to the motor, but will only complete the circuit if the outer covers are closed and projections on the cover press two (!) points on the ribbon to close the circuit.  Any corrosion or deposit (or warpage of the covers) will break the contact and turn your expensive humidifier into a lightweight ship anchor.  And there are so many "idiot-proof" interlocks on this system that any attempt to circumvent them (such as when the outside temperature is -10F, the inside humidity is falling like a rock, your musical instruments are about to explode...and the Airwasher refuses to work because of that speck of corrosion) will prove to be in vain.

The water treatment solution you add to the tank of the Airwasher creates a soap bubble effect between the multiple rotating disks in the tank, and the current of air blows through this "bubble", wafting the moisture out of the Airwasher and into the room.  Unfortunately, some of the soapy emulsion wafts along with the water, coating surfaces in the vicinity of the Airwasher with a dried, soapy residue that is very hard to clean off, and clinging to the inside of the fan housing and onto the fan blades in such a way that cleaning becomes a messy horror.  I was willing in the past to put up with the inconvenience, but with my expensive (and unfixable/unhackable) Airwashers giving up the ghost at the most inconvenient times (And just outside the warranty period!  Imagine that!), I have resolved to run them until they die (one has already given up the ghost) and replace them with less complex and much more dependable evaporative coolers.

Airwashers!  Pah!