

The LV600HH is also the only humidifier we recommend with a warm-mist setting, if that’s something you think you need. This model is exceptionally quiet, too, although it still emits a slight hum, which you might notice in a particularly quiet room. With a large, 6-liter, 1½-gallon tank, the LV600HH should last you more than 24 hours between refills. However, the “auto” setting on this Levoit doesn’t regulate the output as precisely as that on the 300S, so there’s a higher risk this model will over-humidify a room. The Levoit LV600HH Hybrid Ultrasonic Humidifier is our pick for large spaces and exceptionally dry, demanding environments because it provides continuous humidification and has a built-in humidistat that’s reliable and accurate. However, the Classic 300S does still have the other drawbacks of ultrasonics, including a tendency (if you have hard or well water) to leave a trail of fine mineral dust on the furniture or floor (don’t worry, this is harmless and easy to clean). We were surprised how impressed we were with the Classic 300S’s smart-home features, which brought some added convenience into our lives with cleaning reminders, scheduling options, and memorable voice commands via Alexa or Google Home. This machine also has a built-in night-light, if you need a little extra illumination in a room (and if you don’t, it’s easy to turn off the display screen). Its 1½-gallon tank lasts all day, and its fill hole is wide enough that you won’t have to scrub around any awkward corners. The Classic 300S has plenty of other thoughtful features that make it stand out from other humidifiers, too. Over-humidification of a room has been the flaw of nearly every ultrasonic humidifier we’ve tested in almost a decade of evaluation. The Classic 300S also does something no other ultrasonic humidifier can claim to do: Thanks to a built-in humidistat and functional smart features, this model can achieve a target humidity level and maintain it on an “auto” setting that actually works. Also, it won’t bother you at night with beeping or bright lights. It’s easy to clean, and it humidifies the air quickly and (almost) silently.

The Levoit Classic 300S Ultrasonic Smart Humidifier does everything right.
