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Levoit LV600S Smart Hybrid Ultrasonic Humidifier (Warm & Cool Mist) vs Blueair InvisibleMist Humidifier H35i
Which one has the downsides you can live with?
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The short answer
Levoit LV600S Smart Hybrid Ultrasonic Humidifier (Warm & Cool Mist) ranks higher (#1 vs #3 of 8) and scores better on humidifying power, quietness, tank & runtime. Blueair InvisibleMist Humidifier H35i wins on easy cleaning, running cost, durability.
The biggest complaint about the Levoit LV600S Smart Hybrid Ultrasonic Humidifier (Warm & Cool Mist) is breaks or cracks within a season or two; for the Blueair InvisibleMist Humidifier H35i it's small tank. Pick the one whose catch bothers you less.
Side by side
| Levoit LV600S Smart Hybrid Ultrasonic Humidifier (Warm & Cool Mist) | Blueair InvisibleMist Humidifier H35i | |
|---|---|---|
| Rank in humidifiers | #1 | #3 |
| Price tier | $$ | $$ |
| Type | Ultrasonic | Evaporative |
| Amazon 1–2★ share | 11% | 14% |
| Overall score | 3.8 | 3.7 |
| Humidifying power | 5.0 | 3.0 |
| Easy cleaning | 3.5 | 5.0 |
| Quietness | 4.5 | 3.5 |
| Tank & runtime | 4.0 | 3.0 |
| Running cost | 3.5 | 4.0 |
| Durability | 2.5 | 3.5 |
Price tiers: $ under $60 · $$ $60–150 · $$$ over $150. Highlighted = clearly better (a score gap of 0.3 or more, or a 1–2★ share at least 3 points lower). Scores are explained, with sources, on each product's page.
Top complaints
Levoit LV600S Smart Hybrid Ultrasonic Humidifier (Warm & Cool Mist)
- Breaks or cracks within a season or two
Reliability and durability are negative aspects in Amazon's review summary (durability: 101 of 142 mentions negative), with owners describing units that stopped working, tanks that cracked and leaked, and units that broke after about 1.5 years.
- Humidity control gets erratic over time
Wirecutter's tests found the auto mode accurate, but it has heard from readers, staff and Amazon reviewers that the humidity reading becomes unreliable over time. Resetting the unit (hold power for 15 seconds) often helps. Amazon's summary calls humidity output mixed, with some owners saying no mist comes out at all.
- White dust and a fiddly base
Wirecutter warns that, like other ultrasonics, it can leave a trail of fine mineral dust unless you use distilled or filtered water, and the base has nooks that are annoying to clean. Amazon owners are split on cleaning, with some saying there are too many parts to take apart.
- Warm mist runs dangerously hot
Wirecutter notes the warm-mist heating element can get dangerously hot and cites the Mayo Clinic's advice against warm-mist models in homes with children. It also recommends skipping the essential-oil tray.
Source: Wirecutter
Blueair InvisibleMist Humidifier H35i
- Small tank
Wirecutter says the 0.9-gallon tank falls just below its 1-gallon guideline, so larger rooms or very dry climates will mean more refilling.
Source: Wirecutter - Filter cost
The Spruce says the wick filter costs about $30 every six months or so, and Wirecutter says it is designed for a roughly six-month replacement cadence.
Source: The Spruce, Wirecutter - Louder than ultrasonic, and no visible mist
Wirecutter notes its fan makes it louder than an ultrasonic model, though still well below conversation level. The Spruce reports that testers of evaporative models, including this one, wished they could see mist to know it was working.
Source: Wirecutter, The Spruce
Who should pick which
Pick the Levoit LV600S Smart Hybrid Ultrasonic Humidifier (Warm & Cool Mist) if
Medium to large rooms
People who want warm and cool mist in one unit
Smart-home control and auto humidity
Skip it if: You won't buy distilled water; You have small children (warm-mist mode gets very hot); You want a unit that reliably lasts many seasons
Pick the Blueair InvisibleMist Humidifier H35i if
People worried about mold and slime
Bedrooms (no wet mist or fog)
Tap-water users who want an app
Skip it if: You want to see mist to know it's working; You need a big tank for a large room; You want near-silent operation
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