Ultrasonic humidifiers

The cheap one, and honest about being cheap. No humidity sensor, no app, no auto mode - a dial, a 2.5-litre tank and a top-fill opening. For a small bedroom or a desk that is often exactly enough, and the absence of a sensor means there is nothing to drift out of calibration. It is also, unexpectedly, one of the more truthful boxes here: Levoit publishes 190 mL/h at the top of the dial, which is about 1.2 gallons a day and supports very nearly the 290 sq ft on the listing. The catch is that Levoit's two published numbers describe opposite ends of that dial - the 25-hour runtime comes from the 100 mL/h minimum, and at the setting that actually holds 290 sq ft the tank is empty in about thirteen hours. What it cannot do is hold a target: it runs at whatever you set until the tank is empty, which in a small closed room means over-humidifying and a damp window.

The teardrop shape has been on nursery shelves for over a decade and is probably the most recognisable humidifier in America. A gallon of water, twenty-four hours, no filters, and a tank moulded from antimicrobial plastic - Crane's answer to the pink-slime problem, and a partial one, since the material inhibits growth on the tank wall rather than in the water. Crane's own documentation is inconsistent about what it covers: 500 sq ft on most retail listings, 250 in one of its spec sheets. The arithmetic supports the smaller figure.

Honeywell's filter-free line exists because plenty of people would rather buy no consumables than buy the right ones. There is no wick and nothing to replace, which is genuinely the cheapest ownership in the catalog - and it is an ultrasonic with no demineralisation media, so on hard water the minerals that a wick would have caught end up on the furniture instead. A gallon tank and 24 hours works out to about a gallon a day, near enough to what its 300 sq ft claim needs, making this one of the more honest small ultrasonics on that particular number.

Pure Enrichment is unusually straight about runtime: it publishes a range, ten to twenty-four hours depending on the setting, rather than quoting only the flattering end. That one editorial choice tells you more about the machine than any spec - at the high setting a gallon lasts ten hours, which is what a gallon does. It is otherwise an unremarkable and perfectly competent $60 ultrasonic: no filters, a mist dial, an optional nightlight, auto shut-off. The 500 sq ft claim is the usual fiction.

Crane's fix for the original Drop's two real problems - the bottom-fill tank and the neck you could not get a hand into - plus a sound machine and a colour-changing nightlight aimed squarely at nurseries. The top opening is wide enough to reach inside and scrub, which is the single most useful change and the reason to pay $20 more. Three sleep sounds, an aroma tray for vapour pads, and the same one-gallon, twenty-four-hour, no-filter arrangement underneath.

Vicks declines to put a square-foot number on this one, describing it only as a medium-room unit - which, given how the rest of the category behaves, is its own kind of honesty. A 4.5-litre tank running 30 hours works out to just under a gallon a day, the same ballpark as everything else at this price. Dual scent-pad slots, a variable output dial, no filter. The usual ultrasonic caveats apply and the tank neck is narrow enough that cleaning it properly means a bottle brush.

Three washable parts, all stainless steel, all dishwasher safe - that is the entire product thesis and it is aimed squarely at the reason most humidifiers end up in a cupboard. Plastic tanks grow a pink film in the seams and scratch when you scrub them; a steel tank can be boiled, bleached or run through a dishwasher indefinitely. Carepod charges $350 for that, which is four times a Levoit with more capacity. It is still an ultrasonic with no demineralisation media, so hard water still means white dust, and Carepod publishes no room-size figure at all - a gap that reads as caution rather than oversight given what the competition prints.

Dreo does the thing most ultrasonic makers leave to a separate accessory listing: it ships a demineralisation cartridge and tells you when to change it. That single decision is why the HM311S sits in the no-white-dust filter on this site while several pricier ultrasonics do not. The rest is a competent $50 bedroom unit - 4-litre top-fill tank, real humidity sensor, app, 28 dB. Independent testing found it better suited to rooms under about 200 square feet than the 300 on the box, which is roughly where the arithmetic lands too: 300 sq ft wants 1.2 gallons a day and would drain the tank in about 21 hours rather than 32.

A litre more tank than the HM311S and a bigger room-size claim, from the same playbook: demineralisation cartridge in the box, humidity sensor, app, top fill. The 500 sq ft on the listing is the least defensible number Dreo publishes - that room calls for about 2 gallons a day, which would take the 5-litre tank down in roughly 16 hours against the 42 advertised. Treat it as a 250-300 sq ft machine and it is a good one. Against the HM311S it buys a litre of water and an aroma tray for $25; against Levoit's Classic 300S at a similar price it buys the demineralisation cartridge Levoit charges extra for, and gives up the longer-established app.

Vicks sells more humidifiers through drugstore shelves than most of this catalog sells anywhere, and the VUL545 is the one people pick up at nine in the evening when a child has croup. It works: a gallon of water, visible cool mist, a scent pad slot for menthol, and no filter to have forgotten to buy. What it will not do is hold 400 square feet - that room wants about 1.6 gallons a day, four times what the advertised 36-hour run delivers - and on hard water it powders dark surfaces within a few days.

Sixty hours of runtime and 505 square feet cannot both be true at once, and the Classic 300S is the clearest illustration of that in the whole catalog. Drain a 6-litre tank over the advertised 60 hours and the unit is putting out about 0.63 gallons a day, which is bedroom-sized. Hold 505 square feet at 40% and it needs roughly 2 gallons a day, which empties that same tank in under 19 hours. Both numbers come off Levoit's own spec sheet; only the setting changes. What you actually get for $72 is a competent, genuinely quiet ultrasonic for one room, with top filling, a real humidity sensor, an auto mode that targets 40-50%, and app control that owners either use constantly or never touch again. It is an ultrasonic with no demineralisation media, so hard tap water becomes white dust on the nightstand, and the tank wants weekly cleaning or it turns pink.

Ten litres is a floor-standing amount of water, and that is the whole proposition here - Levoit's answer to people who were tired of filling a 6L tank every other day. The 100-hour runtime figure is real at the lowest setting and is the longest in the catalog outside the console evaporatives. It is still an ultrasonic, so the white-dust and tank-hygiene arithmetic is unchanged, and a bigger reservoir means more standing water to keep clean rather than less. Levoit puts 600 square feet on the box; that room needs about 2.4 gallons a day, which drains ten litres in roughly 26 hours.

A tower with a 1.47-gallon tank, a demineralisation cartridge in the box, and a 426 sq ft claim - an oddly specific number that at least suggests somebody calculated rather than rounded up to 500. Seventy hours on the lowest setting is among the longest here, which as usual means the lowest setting moves very little water: about half a gallon a day. Where it earns its place is the combination of a demineralisation cartridge and a real humidistat at $80, which is not on offer from most rivals at this price.

Sold on being easy to clean - a wide 3.5-litre tank you can get a whole hand into, which is a bigger deal than it sounds given that the narrow-necked tank is why most cheap humidifiers end up growing something. Fifty hours on the low setting, no filters, and no room-size claim printed anywhere, which after forty-odd entries in this catalog reads as restraint rather than an omission. What you give up for the wide mouth is a sensor: there is no humidistat, so it runs at the level you set until it is empty, and in a small closed room that is how windows end up wet.