Levoit Classic 300S Ultrasonic Smart Review

Levoit makes several of our top-scoring models, and their reign is well deserved. This unit may just be the most, well, classic and fine-tuned modern option we've seen.

Humidification

The Classic 300S is indeed a classic ultrasonic model, like most humidifiers on the market, meaning it produces 'Cool Mist' by literally vibrating water into vapor through a simple mechanism in the base.

Starting at about 40% relative humidity in our test lab, we found the 300S was able to actively raise humidity a little over 12% in an hour, slightly better than average in our lineup.

Just be sure not to use tap water, with any humidifier model really, but especially with ultrasonic models. Dissolved minerals like Calcium and Magnesium help give water its (subtle) taste that we're used to, but these units will vaporize them along with the water into a fine white dust that'll eventually start to be noticeable on your furniture. And it's not great to breathe.

Ease of Cleaning

Levoit's design is dialed in here, making this unit one the easiest to clean that we've tested. A large tank does mean slightly more surface area to wipe down, but it also makes for plenty of clearance for your hand and a sponge to maneuver around the central vapor tower and get into the top and bottom corners.

Components in the tank and base are fairly rounded and/or easy to access for the most part. Our slight gripe is that there are some smaller crevices in the base unit that will need some extra attention. Cleaning is a task that should be done often to keep nasties at bay, but at least it's not an especially annoying task here.

Noise

The 300S is one of our quieter models. An average running noise level of 38.5dB is about the level of a whisper or a low appliance hum.

That doesn't tell the whole story though. Ultrasonic buzzing effectively turns into a faint, low whine under water load; that's not bad in and of itself, but the specific pitch we found with this model tended to be a bit annoying to some of the test staff. There was also a fairly consistent dripping sound that gradually became noticeable as the tank level dropped.

Overall, this is such a quiet unit that we think all of this likely won't be perceived by most people. But if you're a particularly light sleeper or have sensitivities to sounds, take note.

Ease of Use

Here's why we're particularly excited about the Classic 300S: the tank holds a lot of water. 1.58gal (6L) to be exact. Even at full blast, this guy will run almost two full days (just under 46 hours) on a single fill-up. That's top of our tested lineup, and a big reason why we've given it our 'Most Convenient' award.

This particular model does away with a top folding handle in lieu of two inset side handles, which makes for stable transport. There's also a wide mouth located on top, so you can refill in place if you prefer.

The on-unit interface is minimal and intuitive, but the available VeSync App is the real winner. It's targeted to plant owners, with an included watering schedule tool, and light and humidity suggestions specific to species. The built-in relative humidity sensor makes for a decently accurate 'auto' mode which will keep levels exactly where you want.

Operating Cost

Humidifiers aren't especially expensive to run, as you might imagine, but there's a hidden cost most won't think of off the bat — tap water is not recommended for this machine. Distilled, or what we found to be the cheapest in the long run, water treatment tabs to demineralize your tap water are what you're going to want to use.

We estimate these treatment tabs can cost up to $120/yr for the average household using this about 1/4 of the time. Thankfully, the electric bill is a lot lower, under $10/yr.

Should You Buy the Levoit Classic 300S Ultrasonic Smart?

The Levoit Classic 300S is for any and all users who just want a standard humidifier that does the basics nearly perfectly. There aren't a lot of weaknesses, but there are a few key things to consider. If you want a no-fuss machine that keeps going, this is it, but the constant white noise is worth noting.

What Other Humidifier Should You Consider?

At the end of the day, the 300S is a 'typical' option that just… works. It's a great value in that sense, but still may be a little pricier than some users with more occasional humidifier needs would prefer. The Dreo HM311 is a perfect option for that crowd.