Breathe and sleep easy with this super-quiet humidifier. This model  purifies water and converts it into a soothing plume of vapor.  The unit is shaped like a coffee maker, has a 10-by-6-inch footprint, and  stands 1 foot tall. Clear blue plastic allows you to see how much water  remains in the 1.5-gallon, 20-hour tank. A variable control provides  fine-tuning of mist output, and the dial on the lid allows you to direct the mist (away from  curtains or bedding, for example). Even at a blast the sound is still barely  audible. This tank lies flat for easy filling, but  might be a bit hard to reach into for cleaning. Still, the replaceable  filter strains impurities out of the water, leaving the air clean. Pop open the lid--on this cartridge you'll find a phone number for ordering replacements.--Trilby Cohen