Functionally, the Sunpentown SU-2020 (2016 update) resembles our pick for larger spaces, the SU-4010. It differs chiefly in having a 2-gallon tank, twice the size of the SU-4010’s. Although the higher capacity is tempting, it means a full tank weighs over 16 pounds—a lot to lug around, especially if your sink is far from the humidifier. The big tank also gives it a larger footprint, 8.5 by 12.5 by 14 inches, versus 5 by 13 by 12 inches. That makes it harder to place on a bookshelf or side table—a potential problem, because elevating ultrasonic humidifiers is recommended to help the mist evaporate before it falls to the floor and puddles. And indeed, most complaints about the SU-2020 focus on that issue exactly: the mist condensing on floors, rugs, or furniture, often causing damage.
The Aircare MA0800 (2016 update) is an evaporative humidifier, like our main pick and runner-up. Aircare claims the MA0800 will humidify a space as large as 2,600 square feet. That, to be blunt, is doubtful, and many owners hoping to humidify their whole home with a single unit note that they’ve been disappointed. It gets high marks for durability and its ability to humidify large, though more reasonable, spaces. It’s a big machine, 12 inches deep, 18 wide, and 16½ high—not something you can tuck away on a shelf. It has a large 2.5-gallon tank that weighs more than 20 pounds when full; on the plus side, the manufacturer claims a potential 8 gallons of moisture output per day, which is very high. We’ll likely call one in for the next test, as a “large room” contender; we missed it until now because it’s advertised as a whole-house or “console” humidifier.
On its face, the Pure Enrichment Ultrasonic Cool-Mist Humidifier (2016 update) sure seems popular. But despite its high star rating on Amazon, the authenticity of many of those reviews is questionable. Besides that, its tiny 1½-liter tank means it’s useless for all but the smallest spaces—maybe 125 square feet, a 10-by-12 room. Its (seemingly authentic) negative reviews focus on two other disqualifying factors: It tips over easily, and when it tips, the tank has a tendency to break.
The Opolar 3.8-liter Ultrasonic Humidifier (2016 update) is intriguing because of its wide fill hole, which the manufacturer claims makes it easier to clean. Cleaning humidifiers is vitally important—see Health risks of a dirty humidifier, above—and our main pick’s ease of cleaning is key to our endorsement of it. Otherwise, however, this is a standard-issue ultrasonic humidifier, and in spite of its higher price, it offers no clear advantages over our ultrasonic pick, the Sunpentown SU-4010.
If you must have a budget-friendly ultrasonic, the Safety 1st Ultrasonic 360° Humidifier works, which is impressive for such a cheap unit, but its drawbacks keep it from being a pick. It’s not a bad deal for its currently price of about $30, but you’re going to get only that much worth of humidifier. It runs very quietly and is capable of outputting a fair amount of moisture—it raised our test area’s relative humidity by 17.5 percent over our three-hour testing period. But it’s limited by a tiny 0.8-gallon reservoir that will need frequent refilling, and it lacks a mineral filter, which means you’ll have to use distilled water if you want to avoid mineral dust issues (which you do). Also, it has a two-piece reservoir with a small opening (making it hard to clean) and a long list of customer reviews that complain about leaking and other problems.
The Air-O-Swiss 7135 was an earlier top pick because of its silent operation, humidistat, and prodigious moisture output. Indeed, that it was able to raise an already-moist room’s relative humidity by 34 percent is quite impressive (though it did create a big puddle around the base in the process of doing so). Previously, we put a lot of value into this humidifying ability, but based on feedback we’ve gotten, it’s more than most people need and more than most people want to pay. Its price is already high. Add the highest cost of consumables (water treatments/demineralization cartridges) and electricity ($100 over three years) and you get the humidifier with the highest cost of ownership by far. Plus, its humidistat completely failed to maintain a consistent level.
The Winix Air Washer was effective at humidifying, but had no effect at removing particles and did little to justify its exorbitant price tag. Though it uses the same basic technology as the Venta, its design made it more difficult to use. The base reservoir was not symmetric, and we had to insert the setup disks in the correct orientation.
The Sunpentown SU-3600 Digital Ultrasonic Humidifier with Humidistat is a Sunpentown humidifier that crams a fairly capable machine into a compact, stylish package that would fit on most nightstands. We liked the small size, and it’s nice that the 1-gallon reservoir has a fill cap that seals in an eighth of a turn. But that’s offset by annoying touch-sensitive controls that offer no tactile feedback. You can’t tell what you are doing without looking. It also has a wildly inaccurate humidistat, which read 33 percent for the duration of a run designed to test its ability to hold the humidity constant at 65 percent. Instead of holding steady here, it pumped up the humidity to a muggy 77 percent and soaked the floor. And it’s missing a demineralization cartridge, so you’ll have white dust to contend with or the added cost of distilled water.
The Stadler Form Hera is billed as a top-shelf unit, with warm and cool ultrasonic mists and bidirectional nozzles, a humidistat, and a night mode that automatically dims the display. But our unit generated excessive screeching noise measured at 74 decibels! The humidifier put out mist, but was so loud that we aborted our tests. It’s well-reviewed at Allergy Buyers Club, and we can’t imagine anyone tolerating this noise level, so perhaps our tester was defective. Amazon reviewer Matt states, “Maybe this humidifier provides more advanced features than other models, but since it doesn’t get the basics right it really doesn’t matter.” We have to agree.
The Stadler Form Fred steam humidifier is either sleek and modern, or an ugly alien saucer/mini charcoal grill. It has a 2-gallon reservoir that’s good for all day on high. Controls are simple to use, though quite small: a power button, high-low button, and rotary knob for moisture output. When assembling, your hand gets pinched when installing the reservoir, and the lid is slightly difficult to align. The vent gets very hot during operation, and points toward the back, so you can’t put it close to a wall. Finally, during testing, the output rate varied widely, from 1.0 to 1.9 gallons per day. We cannot recommend it, even if you love its looks.
The Honeywell HWM705B Filter Free Warm Moisture Humidifier is nearly identical to the Vicks. Both are made by Kaz. The Honeywell was more flimsy and the outside got hotter to the touch. Despite consuming the same amount of energy (~230 W), it raised the RH only 15.5 percent, from 55.5 to 71 percent, during our three-hour test. Only choose this model if you must have black.
The Optimus Coolmist Ultrasonic Humidifier is a well-reviewed, bare-bones ultrasonic model with simple dial control and strong 2-gallon-per-day output. We found the output rate high, but extremely variable at 1.0 to 2.1 gallons per day (both on the high setting). The reservoir is a bit small at 1.11 gallons. It contains non-replaceable ceramic filters that will do little to trap minerals and prevent white dust.
Dyson’s AM10 is a uniquely shaped ultrasonic humidifier that builds on their earlier fan models. We wondered what you might get for spending as much as possible for a humidifier. The biggest difference from a basic ultrasonic model to one that costs much more is that it has a powerful fan to force the water droplets out through the oval opening. We found it solidly constructed and attractively designed and, well, different. Though not necessarily in a good way. For instance, you have to remove the oval portion before accessing the water reservoir. That’s an extra step. The tank’s fill hole is quite small, about the size of a quarter, making it more difficult to fill and harder to turn the knob to seal. Control is possible only via the remote, and the display is quite small and dimly lit. It performed well, ranking first on ability to hold relative humidity at a set point (average 1.4 percent RH over the set point, and 0.8 percent RH standard deviation), and third on humidity change (25.5 percent RH). Dyson definitely makes a statement with its design, but it fails to deliver value. Save your $500 to spend or invest elsewhere.
The Vornado Evap3 is a very attractive model. It aced the humidity-hold test, reaching the steadiest value among evaporative models, 3.6 percent over the set point and 1.0 percent standard deviation. It has a moderate 1½-gallon tank and high output of 2.7 gallons per day. It uses two wicking filters that last for four to eight weeks before they need to be replaced, at a cost of $12. Operating modes are high, low, or auto, with a built-in humidistat with values ranging from 35 to 60 percent RH, or continuous operation. Unfortunately, it’s a little bit loud on high (54 decibels), just making our 55-decibel cutoff, and the fill cap is really hard to turn.
The Vornado Evap2 is a promising humidifier and the little version of the Evap3 model. It uses a single wicking filter. It also performed well on the humidity hold, coming in second among evaporative models. But it’s too loud (59 decibels), and inserting the reservoir is too awkward. Aligning the base is also tricky as it has to come in at an angle, and we found ourselves struggling each time we refilled.