Who this is for
The Honeywell HCM-350 (front), and (back, from left) the SPT SU-4010, SPT SU-9210, Safety 1st, and Air-O-Swiss 7135. Photo: John Holecek
If you are bothered by any of the symptoms caused by dry air, such as dry sinuses, nosebleeds, cracked and sore lips, or shocks from static electricity, the air in your home is likely too dry. Getting a humidifier would help to ease these symptoms. On the other hand, if you notice condensation routinely forming on the inside of your windows or you frequently find yourself having to clean mold off your walls or window frames, your home is too humid, so you don't need a humidifier.
How we tested
We tested the humidifiers in a climate-controlled space while regularly logging temperature, humidity, and particle count where applicable. Then we evaluated them for ease of use and ease of cleaning, which are just as important as humidifying power. A typical humidifier is full of nooks and crannies that funky stuff loves to grow in, and because some of those dirty parts house the electronics, they can be difficult to clean. We also evaluated noise levels and the cost of ownership over an expected product lifetime of three years.
Unlike other humidifiers, the tray in the Honeywell HCM-350 is dishwasher safe and has few right angles where gunk can accumulate. Photo: Ganda Suthivarakom
The Honeywell HCM-350, which has an affordable price tag, performed consistently well across all of our tests and was the easiest model to clean and fill, which are the two things you'll be doing most often with any humidifier. The HCM-350 is designed so that every part that touches water is free of electronic components and sharp angles for easy washing, and the reservoir and water tray are dishwasher safe. Also, this model is the only humidifier we've found that has a seamless, molded reservoir, which eliminates a common problem in inferior models: leaks.
As the HCM-350 has ranked among the best-selling humidifiers on Amazon for quite some time, it's unlikely to become unavailable. But if it does, we recommend a runner-up in our full guide.
For larger rooms
The Sunpentown SPT SU-4010 is best for rooms larger than 400 square feet.
Evaporative humidifiers like the Honeywell are a better value for most people, but if you have a room that's larger than 400 square feet, the Sunpentown SPT SU-4010 ultrasonic humidifier is your best bet. It has an ion-exchange water filter that helps keep microbial growth and mineral dust—issues that are common with ultrasonic models—to a minimum, and it has dual mist spouts that you can aim toward the part of the room you want the humidity to hit (or aim away from things that should stay dry). It's more effective than the Honeywell at humidifying a large bedroom, and it performs as well as models that cost twice as much. However, the base of the unit has electronics attached, and mildew tends to build up along several sharp angles inside, so it isn't easy to clean. It can also overhumidify if you're not careful.
More expensive but very efficient
An inside view of the Venta LW25's rotating disk and reservoir system. Photo: John Holecek
The Venta Airwasher LW25 is worthy of its high price tag only if you are willing to pay a lot more money up front for lower power consumption and less-frequent cleanings. The LW25 works by moving air over a set of slowly rotating discs. It's incredibly energy efficient, drawing only 7 watts on high, yet effective at humidifying, despite using only 0.2 gallon of water per day. While your typical humidifier needs cleaning about every third day, the Venta requires cleaning only every 10 to 14 days and relies on a proprietary chemical mixture to keep funk down between cleanings. It also has a large reservoir that can go a couple of days between refills. Whether those features are worth a lot of money is up to you.
What about warm-mist humidifiers?
Although we strongly prefer evaporative or ultrasonic humidifiers, we know that some people prefer warm-mist humidifiers. We have a warm-mist humidifier pick—and some general words of caution about them—in our full guide to humidifiers.
Wrapping it up
After a third year of testing, we think that the Honeywell HCM-350 is still the best humidifier for most people. This machine combines solid performance with a virtually leakproof, dishwasher-safe reservoir. And among the humidifiers we tested, it's the easiest to fill and clean, too.
This guide may have been updated by The Sweethome. To see the current recommendation, please go here.