Humidifiers / Levoit Classic 300S (Classic300S) vs Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
Levoit Classic 300S (Classic300S)
$79.99
VSHoneywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
$89.95
Levoit Classic 300S (Classic300S) vs Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
Levoit Classic 300S (Classic300S)
The smart ultrasonic everyone buys — and the one that will powder your nightstand.
Wins overall by 0.0 points
Quick Verdict
This is close. The Levoit Classic 300S (Classic300S) edges ahead by 0.0 points, but that margin is inside the noise — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) is a defensible pick on its own terms. A fifteen-year-old evaporative workhorse with UV — and no humidistat at all.
The Levoit Classic 300S (Classic300S) and Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) are both closely matched humidifier models, and the Levoit Classic 300S (Classic300S) is $10 cheaper than the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) ($79.99 vs $89.95). On Freedom From White Dust, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads (9.5 vs 2.5/10) — the thing marketing never mentions. Ultrasonic humidifiers aerosolise whatever is dissolved in the water and deposit it as white dust on furniture — the EPA notes they are 'very efficient at dispersing minerals in tap water into the air', along with microorganisms from the tank. Evaporative and boiled-steam units do not do this at all. A high score means the technology cannot produce dust; a low score means you are buying distilled water for the life of the machine.. On Humidity Control, the Levoit Classic 300S (Classic300S) leads (8.5 vs 3.0/10) — whether there is a genuine closed-loop humidistat holding a setpoint, or just fixed output steps and a timer with a humidity label on it. On Runtime & Refill Interval, the Levoit Classic 300S (Classic300S) leads (8.5 vs 5.5/10) — 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. Overall, the Levoit Classic 300S (Classic300S) scores 6.8/10 across our 8 scoring categories versus 6.8/10 for the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B), though the gap is close enough that your specific use case should decide it. Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Levoit Classic 300S (Classic300S) | Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) |
|---|---|---|
| Price | $79.99 | $89.95 |
| Release Year | 2021 | 2009 |
| Humidification Technology | Ultrasonic cool mist — a piezoelectric disc shatters water into a visible aerosol that is blown out of a nozzle | Evaporative wick with a UV chamber in the water tray — a fan pulls air through the wet HAC-504AW filter |
| 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 | None. The mineral load stays in the wick, which is why Honeywell's manual explains that brown or rust-coloured "mineral deposit" staining on the filter is normal and does not affect performance. Tap water is fine |
| Tank Capacity | 1.58 gal / 6 L, top-fill | 1.1 gal / 4.2 L |
| 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 | "2 US gallons (7.6 liters) output per day" per Honeywell's own manual — which is nearly twice the tank. Meeting the rated output means filling the 1.1 gal tank roughly twice a day, not once |
| 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 | "Up to 24 hours" — on the LOW of three settings. That is 1.1 gal in 24 h, which is barely half the rated 2 gal/day output; the two headline numbers describe two different settings |
| Rated Room Coverage | 215-505 ft² / 20-47 m² (Levoit) | Sources conflict: Honeywell's own product page says only "medium room" with no square footage, while FiltersFast's listing for the same model states 500-800 ft² |
| 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" | None. Three fixed output speeds on a mechanical dial, no humidity sensor, no auto mode and no auto shut-off when the tank runs dry — you are the humidistat |
| 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 | Not published as a decibel figure by Honeywell; the product page says only "quiet operation". It is a 60W fan drawing air through a wet wick, so the top speed is clearly audible |
| 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 | Two separate consumables. The HAC-504 "Filter A" wick is $32.95 for a Honeywell 3-pack (a compatible FiltersFast 3-pack is $22.99) and Honeywell says replace it every 30-60 days. On top of that the Protec antimicrobial cartridge is a 30-day item. A full heating season is realistically $40-70 |
| 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" | Among the best here. The tank and tray go on the dishwasher's top rack, the tank opening takes a hand, and the manual's disinfection routine is one teaspoon of bleach per gallon. Honeywell says only that it "requires regular cleaning" without naming an interval; the EPA says every third day |
| UV / Antimicrobial Claim | None claimed. No UV lamp, no silver-ion or antimicrobial coating, no bacteriostatic additive supported | Two claims, both qualified. The UV chamber is rated "Up to 99.9% Germ Free*", where the asterisk in Honeywell's own manual ties it to independent testing of microbial reduction after two hours of UV exposure — a water-tray claim, not an air claim. The wick itself is separately treated as a Protec antimicrobial filter |
| 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 | Cool, invisible vapour at room temperature — no burn risk at all, which is why this is the standard nursery recommendation |
| Warranty | 24 months | 36 months |
| Colors | White, Gray, Blue | White, Black |
Category Scores
Freedom From White Dust
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 9.5 against 2.5 — a 7.0-point margin on the thing marketing never mentions. Ultrasonic humidifiers aerosolise whatever is dissolved in the water and deposit it as white dust on furniture — the EPA notes they are 'very efficient at dispersing minerals in tap water into the air', along with microorganisms from the tank. Evaporative and boiled-steam units do not do this at all. A high score means the technology cannot produce dust; a low score means you are buying distilled water for the life of the machine.. If that is what you are buying for, the Levoit Classic 300S (Classic300S) does not close the gap elsewhere.
Output
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 7.5 against 7.0 — a 0.5-point margin on actual moisture put into the room per day in gallons or mL/hr, judged against the coverage the manufacturer claims — not the square-footage number on the box. If that is what you are buying for, the Levoit Classic 300S (Classic300S) does not close the gap elsewhere.
Runtime & Refill Interval
The Levoit Classic 300S (Classic300S) leads clearly here, 8.5 against 5.5 — a 3.0-point margin on 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. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Cleaning & Access
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 8.5 against 7.5 — a 1.0-point margin on whether the tank opening takes an adult hand, whether any part is dishwasher-safe or boilable, and how realistic the manufacturer's stated cleaning interval is to actually keep to. If that is what you are buying for, the Levoit Classic 300S (Classic300S) does not close the gap elsewhere.
Running Cost
The Levoit Classic 300S (Classic300S) leads clearly here, 5.5 against 5.0 — a 0.5-point margin on wicks, demineralisation cartridges, antimicrobial additives, distilled water and electricity — everything you keep paying after the purchase. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Quietness
The Levoit Classic 300S (Classic300S) leads clearly here, 7.0 against 6.0 — a 1.0-point margin on noise at the setting people actually run it overnight, weighted toward independently measured figures over manufacturer claims. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Humidity Control
The Levoit Classic 300S (Classic300S) leads clearly here, 8.5 against 3.0 — a 5.5-point margin on whether there is a genuine closed-loop humidistat holding a setpoint, or just fixed output steps and a timer with a humidity label on it. If that is what you are buying for, the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) does not close the gap elsewhere.
Safety Around Children
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) leads clearly here, 9.5 against 8.0 — a 1.5-point margin on burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery. If that is what you are buying for, the Levoit Classic 300S (Classic300S) does not close the gap elsewhere.
Best For
Choose the Levoit Classic 300S (Classic300S) if…
- • Humidity Control matters most to you — the Levoit Classic 300S (Classic300S) scores 8.5/10 here (whether there is a genuine closed-loop humidistat holding a setpoint, or just fixed output steps and a timer with a humidity label on it).
- • Runtime & Refill Interval matters most to you — the Levoit Classic 300S (Classic300S) scores 8.5/10 here (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).
- • You want to spend less — it's $10 cheaper.
- • Your main use case is easy-clean.
Choose the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) if…
- • Freedom From White Dust matters most to you — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 9.5/10 here (the thing marketing never mentions. Ultrasonic humidifiers aerosolise whatever is dissolved in the water and deposit it as white dust on furniture — the EPA notes they are 'very efficient at dispersing minerals in tap water into the air', along with microorganisms from the tank. Evaporative and boiled-steam units do not do this at all. A high score means the technology cannot produce dust; a low score means you are buying distilled water for the life of the machine.).
- • Safety Around Children matters most to you — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 9.5/10 here (burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery).
- • Cleaning & Access matters most to you — the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores 8.5/10 here (whether the tank opening takes an adult hand, whether any part is dishwasher-safe or boilable, and how realistic the manufacturer's stated cleaning interval is to actually keep to).
- • Your main use case is no-white-dust.
Pros & Cons
Levoit Classic 300S (Classic300S)
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
Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)
Pros
- +Evaporative plus UV: no white dust, no distilled water, and a genuine (if narrowly worded) kill stage on the water
- +Tank and tray are top-rack dishwasher safe, which almost nothing else in this category can say
- +2 gal/day rated output is real humidification, not a desktop trickle
- +Three-year warranty and a filter supply chain that has existed for fifteen years — parts are trivially available
Cons
- −No humidistat, no auto mode and no auto shut-off — it runs until you stop it, and the FiltersFast listing states the omission outright
- −The 2 gal/day output and the 24-hour runtime cannot both be true at once: the 1.1 gal tank means hitting rated output requires two fills a day
- −Two stacked consumables — a $23-33 three-pack of wicks every 30-60 days plus a 30-day Protec cartridge
- −Honeywell publishes no square footage and no decibel rating; retailers fill the gap with a 500-800 ft² figure Honeywell does not make
- −Honeywell's own store now marks the HCM350 discontinued and points buyers at the HEV320W, even though the model is still stocked and supported elsewhere
Shop by Need
FAQs
Is the Levoit Classic 300S (Classic300S) or Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) better overall?+
Based on our 8-category scoring, the Levoit Classic 300S (Classic300S) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Freedom From White Dust, the Levoit Classic 300S (Classic300S) or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores higher on Freedom From White Dust (9.5/10 vs 2.5/10) — the thing marketing never mentions. Ultrasonic humidifiers aerosolise whatever is dissolved in the water and deposit it as white dust on furniture — the EPA notes they are 'very efficient at dispersing minerals in tap water into the air', along with microorganisms from the tank. Evaporative and boiled-steam units do not do this at all. A high score means the technology cannot produce dust; a low score means you are buying distilled water for the life of the machine..
Which is better for Humidity Control, the Levoit Classic 300S (Classic300S) or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Levoit Classic 300S (Classic300S) scores higher on Humidity Control (8.5/10 vs 3.0/10) — whether there is a genuine closed-loop humidistat holding a setpoint, or just fixed output steps and a timer with a humidity label on it.
Which is better for Runtime & Refill Interval, the Levoit Classic 300S (Classic300S) or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Levoit Classic 300S (Classic300S) scores higher on Runtime & Refill Interval (8.5/10 vs 5.5/10) — 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.
Which is better for Safety Around Children, the Levoit Classic 300S (Classic300S) or the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) scores higher on Safety Around Children (9.5/10 vs 8.0/10) — burn and scald risk from boiled or heated water, tipping hazard, and whether the hygiene story holds up in a nursery.
Is the Levoit Classic 300S (Classic300S) worth the price difference over the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Levoit Classic 300S (Classic300S) is the cheaper option at $79.99 versus $89.95. Whether the pricier model is "worth it" depends on how much you value its lead in Freedom From White Dust.
Which is better suited to my use case?+
The Levoit Classic 300S (Classic300S) is the better fit if you mainly care about easy-clean. The Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) is the better fit for no-white-dust.
What's the warranty on the Levoit Classic 300S (Classic300S) vs the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B)?+
The Levoit Classic 300S (Classic300S) ships with a 24-month warranty; the Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) ships with a 36-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
Levoit Classic 300S (Classic300S) — $79.99
Premium Option
Honeywell HCM350 Germ Free Cool Mist Humidifier (HCM350W / HCM350B) — $89.95
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.