Humidifiers / Levoit
Levoit Classic 300S (Classic300S)
The smart ultrasonic everyone buys — and the one that will powder your nightstand.
Overall score 6.8/10
Pros
- + One of the few sub-$100 humidifiers with a genuine closed-loop humidistat rather than a timer wearing a humidity label
- + 6L top-fill tank goes two nights between refills at bedroom output levels
- + Auto mode plus app scheduling actually works unattended — TechGearLab rated the humidity tracking accurate
- + Cleaning access is unusually good for an ultrasonic: wide top opening, clearance round the tower
Cons
- − Ultrasonic, so it aerosolises every mineral in the water as white dust on furniture and into the air, and Levoit sells no demineralisation cartridge for it — distilled water is the only fix
- − Levoit publishes no output figure at all: no mL/hr, no gallons per day, so the "215-505 ft²" coverage claim cannot be checked against anything
- − The "up to 60 hours" runtime is the low setting only; run it on high in a genuinely dry room and you are refilling daily
- − Measured 38.5dB against a claimed 30dB, with an audible ultrasonic whine and dripping as the tank drains
- − No antimicrobial or UV stage of any kind, so the every-third-day cleaning the EPA recommends is the entire hygiene plan
Levoit Classic 300S (Classic300S) review: what the specs say
The smart ultrasonic everyone buys — and the one that will powder your nightstand. At $79.99, Levoit's 2021 model sits in the middle of the range — the humidifiers we compare run from $19.79 to $299.99. It scores 6.8/10 overall, calculated from published specifications across 8 categories rather than from a subjective impression.
Its strongest showing is Runtime & Refill Interval at 8.5/10 — how long a full tank really lasts at a useful output setting, rather than at the lowest setting the runtime is quoted for, and how painful the refill is. The weakest is Freedom From White Dust at 2.5/10, which is the trade-off to weigh before buying: if that is the specification you care about most, one of the alternatives below will serve you better.
Worth knowing before you buy: ultrasonic, so it aerosolises every mineral in the water as white dust on furniture and into the air, and Levoit sells no demineralisation cartridge for it — distilled water is the only fix; and levoit publishes no output figure at all: no mL/hr, no gallons per day, so the "215-505 ft²" coverage claim cannot be checked against anything. Every specification on this page comes from Levoit's own documentation or a verified retail listing — where a figure is not published, the table says so rather than estimating it.
Specifications and price last verified . Report an error
Full Specifications
| Humidification Technology | Ultrasonic cool mist — a piezoelectric disc shatters water into a visible aerosol that is blown out of a nozzle |
| White Dust & Mineral Aerosol | Yes, and there is no fix sold for it. the EPA's "Use and Care of Home Humidifiers" states that ultrasonic and impeller humidifiers "are very efficient at dispersing minerals in tap water into the air" and that they "can disperse materials, such as microorganisms and minerals, from their water tanks into indoor air". Levoit sells no demineralisation cartridge for the Classic 300S — the part in the box is an aroma pad and a water-filter sponge, neither of which removes dissolved minerals. TechGearLab's tester warns that on tap water the minerals "eventually start to be noticeable on your furniture". Distilled water is the only real remedy, at roughly $1-1.50 per gallon |
| Tank Capacity | 1.58 gal / 6 L, top-fill |
| Rated Output per Day | Not published by the manufacturer — Levoit publishes runtime and a 26W rated power but no mL/hr or gallons-per-day output figure anywhere on the spec sheet |
| Quoted Runtime (and at which setting) | "Up to 60 hours" — Levoit's own page attaches that figure to the LOW mist setting. 6 L over 60 h is only about 100 mL/hr; on high the same tank empties in a small fraction of that time |
| Rated Room Coverage | 215-505 ft² / 20-47 m² (Levoit) |
| Humidistat | Real closed-loop humidistat. An onboard humidity sensor feeds Auto mode, which holds 40-50% RH or a custom setpoint; TechGearLab called the auto mode "decently accurate" |
| Noise | Levoit claims 30dB or less. TechGearLab measured 38.5dB and describes an ultrasonic whine plus a steady dripping noise as the tank empties — a bedroom-relevant gap between claim and measurement |
| Filters & Cartridges (Annual Cost) | No wick and no demineralisation cartridge exist for this model, so the strictly required consumable cost is $0/yr. In practice the running cost is distilled water — roughly $1-1.50 a gallon, or about $45-90 over a 60-day heating season at one tank every two days |
| Cleaning Burden & Dishwasher-Safe Parts | Above average. The top-fill opening takes an adult hand and the vapour tower has clearance around it; TechGearLab scored cleaning 8.5/10 but flagged small crevices in the base. Nothing is dishwasher-safe. The EPA advice is to "clean portable humidifiers every third day" |
| UV / Antimicrobial Claim | None claimed. No UV lamp, no silver-ion or antimicrobial coating, no bacteriostatic additive supported |
| Mist Temperature & Burn Risk | Cool mist at room temperature — no burn risk, but equally no thermal kill step, so whatever is living in the tank is aerosolised with the water |
| Connectivity | 2.4GHz Wi-Fi, VeSync app, Amazon Alexa, Google Assistant |
| Material | Not published by the manufacturer — Levoit's spec sheet lists no housing or tank material |
| Warranty | 24 months |
Compare Levoit Classic 300S (Classic300S) With
Cheaper Alternative
Crane Drop EE-5301 Ultrasonic Cool Mist Humidifier — $44.99
Premium Alternative
Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) — $89.95