The Best Humidifier
A low-maintenance humidifier that self-regulates to prevent over-humidification. Unlike competitors, it’s not prone to bacterial growth or emission.
A self-regulating humidifier with additional options for specific humidity levels. However, it can be a little noisy and requires more regular cleaning to prevent bacterial growth.
The Best Humidifier
If you suffer from dry skin, sinus pain, or cracked lips, chances are the air in your home or office is too dry. Humidity levels will also naturally drop as winter approaches — cold air holds less moisture than warm and heaters dry out the air even more. A good humidifier can add the right amount of moisture to the air to alleviate pesky symptoms and maintain an optimal humidity level of 30 to 60 percent.
Our top pick for humidifiers is the Honeywell HCM 350 ($58). The Honeywell is an evaporator — the only type of humidifier that self-regulates to prevent over-humidification that can lead to mold and bacteria. That means you can enjoy safe and balanced humidity levels without having to supervise your machine. Better still, studies also show that the Honeywell is not prone to growing or emitting bacteria — a common problem for competing models. It’s also a breeze to clean and we appreciated its low-maintenance design. We missed the built-in humidity meter that other models offered, but its natural failsafe for preventing too much humidity means that’s not a dealbreaker — the Honeywell was hands-down our favorite.
If you want a bit more control over the humidity levels in your home, we recommend the Vornado EVAP3 ($90). Like the Honeywell, It’s an evaporator, so you won’t have to worry about over-humidifying your home. With the higher price tag comes a built-in humidistat — a device that measures humidity levels and adjusts output — so you can set a specific humidity level within the 30 to 60 percent range for maximum comfort. The tradeoff? The humidifier is prone to growing bacteria in the reservoir tank (don’t worry, though, it won’t spew it into the room) and a bright blue light on the machine can be a nuisance during the night. We prefer the hygienic and less-intrusive design of the Honeywell, but the Vornado Evap3 is a solid alternative.
How We Found The Best Humidifiers
Room shape and size mattersThe humidifiers on our list will suit the average room (about 400-500 sq. ft.), but if you have a large room or high ceilings it may take longer to reach optimum humidity levels. If you have an incredibly large room, investing in two humidifiers is a better option.
To find our contenders, we looked at best-of lists from consumer advocacy and tech sites, such as Consumer Reports and Digital Trends, for humidifiers that outperformed others when it came to reaching optimal humidity levels. We also compared consumer reviews on sites like Amazon, Target, and Bed, Bath & Beyond to find humidifiers that earned high marks for hassle-free cleaning and maintenance. After hours of research, we found the most consistently celebrated humidifiers to maintain balanced humidity levels in an average-sized room (think living area or bedroom).
First, we evaluated different technologies and brought in the best evaporators and ultrasonics.
Not all humidifiers are created equal. Different technologies for producing mist effect the comfort and humidity level in your home, as well as the time you’ll spend cleaning. We separated our contenders into four categories — evaporators, ultrasonic, warm mist, and airwashers — to compare the pros and cons of each method. You can read more about the differences between them below. The bottom line? Evaporators are the best bet for most people. For one, they self-regulate, relying on the natural process of evaporation, which decreases when humidity levels are high. They also have a lower risk of emitting bacteria, meaning you can breathe easy while enjoying safe and balanced humidity levels.
That said, the 14 humidifiers we brought in for testing were not all evaporators. After all, other models — in particular, ultrasonics — are incredibly popular, and we wanted to see for ourselves if they offered anything to outweigh the benefits of an evaporator. (Spoiler alert: they didn’t.)
Then, we tested how well our machines maintained safe humidity levels.
Keep a hygrometer handyAir quality expert and CEO & Co-founder of Airboxlab, Jacques Touillon, explained “you need to be able to read what’s in the air to protect yourselves from excessive or scarce humidity.” Keeping a hygrometer in your home at all times of the year can help you know when to use your humidifier and when you can keep it in storage.
The best humidifiers should maintain humidity within a range of 30 to 60 percent. Go below 30 percent, and you won’t escape dry noses and staticky doorknobs. Go above 60 percent and over-moist air leads to mold or mildew that can be harmful to your health and home. During testing, we spaced hygrometers (devices that measure humidity levels) around our testing room to see how well each humidifier could reach and maintain specific humidity levels throughout a whole room.
We tested various humidity levels between 30 and 60 percent as recommended by most of our manufacturer manuals (this can vary slightly depending on location and season, though). All of our humidifiers were able to reach optimal humidity levels, but several came close to over-humidifying our testing room. For example, the Boneco 7135 Ultrasonic’s built-in humidistat wasn’t accurate, underestimating the real humidity level of our testing room by as much as 20 percent. That means its impressive output of mist could unwittingly keep pumping up to 80 percent humidity, leading to moist walls and dangerous mold. No thanks. Others, like the Sunpentown Su-4010 Dual Mist Ultrasonic, didn’t fare much better. In the absence of a built-in humidistat (and without the inherent self-regulation of evaporators) their impressive mist output easily over-humidified our room.
We gave preference to humidifiers that reached and, most importantly, maintained optimal humidity levels with minimal supervision. We like humidifiers that we can set and forget (until it’s time to refill) and the Honeywell HCM 350 and the Vornado Evap3 aced our testing.
Finally, we compared overall design for ease of use, maintenance, and cleaning.
Most of our humidifiers were pretty easy to use and maintain. The controls were straightforward and removing the tanks and replacing the filters was simple. Though if we nitpick, the SPT SU-9210 evaporator had controls that produced a loud beep and a bright display that would be disruptive at night. The humidifier also had parts that were just a touch more difficult to clean and refill, leading us to make a few small spills.
As for cleanliness, the Honeywell HCM 350 takes top spot. According to a Consumer Reports evaluation of humidifier cleanliness, it had no significant bacterial growth in the reservoir and no potential to emit bacteria. The SPT SU-9210 and Vornado Evap3 both had some bacterial growth in the reservoir, although no potential to emit that bacteria. To be fair, we are nitpicking again, since none of our finalists actually emit bacteria and regularly cleaning your humidifier tank will reduce the likelihood of it forming in the first place. But when it comes to finding the best, small differences matter, and after hours of comparisons we had two favorites.
Our Picks for Best Humidifier
When it comes to maintaining safe humidity levels without accumulating bacteria, the Honeywell HCM 350 takes the crown. It may be lacking the high-tech features of other models, like a built-in humidistat, but the Honeywell HCM 350 is the best at what it’s designed to do: safely humidify.
As an evaporator, the Honeywell relies on the natural process of evaporation to humidify — as the amount of moisture in the air rises, the ability of water to evaporate naturally decreases. That means the Honeywell self-regulates and you won’t have to worry about the mold or mildew that comes from exceeding safe humidity levels. The machine also emits moisture as water vapor, instead of heavy mist, which means you won’t have to worry about puddles or white dust — common problems for ultrasonic models. Using the humidifier is as simple as filling it up and turning it on, and out of all the machines we tested, the Honeywell HCM 350 was the easiest to set and forget. Of course, you will have to refill the one-gallon tank every 12 hours, so you can’t forget it completely, but the tank has a large hole and sits upright which makes refilling a breeze.
The biggest draw of the Honeywell HCM 350 is its cleanliness. Cleaning the machine is easy — all the parts that require cleaning are submersible and easy to rinse, unlike competitors that have parts attached to electronics. It’s also the only humidifier on our list with no significant bacterial growth risk in the reservoir or potential to emit bacteria. Add to that replacement filters that cost a low $8, and you have an affordable humidifier that provides comfort with fewer germs.
The Honeywell HCM 350 does have a few flaws. The high setting is fairly loud, which can be distracting, making this a poor match for light sleepers. In addition, the humidifier doesn’t have a humidistat to set a specific humidity level, although as an evaporator it naturally decreases output as humidity increases. The Honeywell HCM 350 outperforms all others when it comes to the criteria that count: producing safe and healthy humidity levels.
Going above and beyond the basic self-regulating perks of other evaporators, the Vornado Evap3 has an intuitive button interface that allows you to set specific humidity ranges, giving you more control.
The Vornado does this thanks to its on-board humidistat — a device that adjusts the output of mist to match a pre-set humidity range (with outer limits of 35-60 percent). More importantly, its humidistat is actually quite accurate, with just a five-percent margin of error. Translation? You can choose the range that brings you the most comfort without having to worry about reaching unsafe humidity levels. By comparison, the Honeywell HCM 350’s only customization is its fan speeds.
Customization options aside, we also gave points to the Vornado for being easy to maintain. It comes with a 1.5 gallon tank that only needs refilling every 12 hours. And while we were initially worried that the use of two filters would make maintenance tedious and costly, we were glad to see that replacing filters was painless and that a $13 replacement will last a standard one to two months.
Regular cleaning (daily rinsing and one deeper clean each week) is essential with the Vornado. After all, the Consumer Reports study we mentioned earlier shows its reservoir is susceptible to bacterial growth. Rest assured, the same studies show that the Vornado won’t emit bacteria, but regular cleaning will help prevent its build up in the first place. There are two small annoyances we should flag with the Vornado: the small blue light on the control panel is very bright, which may disturb some sleepers, and the machine is noticeably loud on its highest fan setting. Popular user hacks for these minor shortcomings include covering the blue light with some tape, and sticking to the lower fan settings, at least at night, so they weren’t dealbreakers for us.
Despite a slight resemblance to a Keurig coffee maker, the Vornado Evap3 is a pleasant and unobtrusive addition to any room. It will fit neatly in a corner or on a table and, on its lower fan settings, will quietly add moisture to the air without producing the distraction of wafting mist. For those who want a safe and reliable humidifier with just a bit more control over humidity levels, the Vornado Evap3 is a solid alternative to our top pick.
A primer on different humidifier technologies
At their core, all humidifiers are designed to add moisture to the air. But different humidifiers use different methods to produce mist. The short version is that an evaporator is the best choice for most people, but we discuss the strengths and weaknesses of each type below.
Evaporators blow air over a wet wick or filter to release moisture as a cool mist. The evaporation from the wick depends on the humidity of your room — as humidity levels rise, the output of mist naturally decreases. In other words, evaporators self-regulate to maintain a safe and comfortable balance of humidity. According to a study led by Consumer Reports, they are also the least likely to grow and emit bacteria. The catch? The wicks need replacing every two to three months, and they tend to be slower and louder than their counterparts.
Ultrasonic humidifiers vibrate a diaphragm with sound waves to produce mist quickly and quietly — no wick or filter necessary. But their silent and efficient design comes with a few tradeoffs. Since they don’t use the natural process of evaporation, most do not self-regulate. Those that do rely on a built-in humidistat, a device that measures humidity levels and adjusts output, but these aren’t always accurate (it depends on the humidifier and manufacturer). That means ultrasonics require supervision to prevent over-humidification. You will also have to spend more time cleaning — ultrasonic models are more prone to emitting bacteria and white dust (a powder of minerals from water that is harmless but a chore to wipe up).
Warm mist humidifiers use an internal heater to boil water and release steam. The warm mist can be soothing in colder months, and many let you infuse menthol for even greater comfort. But we couldn’t overlook one glaring flaw: safety concerns. A snagged cord or bumped table could easily lead to scalding. For any household, especially those with young children or pets, this adds unwelcome danger. Also, the temperature of the water makes no difference to the spread of germs, although regularly cleaning your humidifier can.
Airwashers are a combination of evaporators and air purifiers. They promise balanced humidity levels and the ability to remove large particles, like pollen and dust mites, from the air. But since air quality experts recommend an air purifier with a True-HEPA filter (the standard for filtering airborne pollutants and something air washers typically lack), you’re actually better off getting a separate air purifier to work alongside your humidifier. Airwashers are also expensive — even purchasing the best air purifier alongside one of our humidifier top picks will save you about a $100 compared to investing in a pricey airwasher.
Impeller humidifiers use spinning discs to fling water at a diffuser that then sends water droplets into the air. In theory they should work well, but all the impellers we looked at received a lot of negative reviews on sites like Amazon. Customers report low moisture output and excessive white dust. Simply put, the other styles were far more popular, and impeller humidifiers didn’t show up on any best-of lists during our research.
You can make your own humidifier cleaner
Dr. Sarah Kohl, a clinician with over 25 years of experience, told us “bacteria are everywhere...if people don’t clean their humidifier, it can spew mold or bacteria into the environment. Cleaning your humidifier regularly will take care of any health risks.” While our top picks aren’t prone to emitting bacteria, waiting too long to clean your machine will eventually result in bacterial growth — moisture makes this unavoidable.
You can pick up a humidifier cleaner for around $10, but most manufacturers suggest a DIY method in their manuals. Common solutions use a teaspoon of bleach or vinegar mixed with a gallon of water that is poured into the base tray.
A humidifier won’t cure what ails you
According to Dr. Kohl manufacturers will promise a lot of health benefits from using a humidifier, but “there are no real good scientific studies to support these claims.” She explained that humidifiers “do what they’re designed to do — humidify the air. They’re just going to make you feel more comfortable.” That’s not to say humidifiers aren’t useful. Dr. Kohl explained that while you’ll still have to wait for any cold or flu to pass, there’s no harm in a little extra relief from dry noses and skin while you recover.
Pets share our ideal humidity range
Keeping humidity levels within 30 to 60 percent is also important for pets. Humidity levels under 30 percent can lead to dry skin and aggravated allergies while humidities above 60 percent can make it too hot for your dog or cat. The symptoms are relatively easy to spot — for example, dandruff during the dry winter or abnormal thirst are good signs that your humidity levels are unbalanced. We recommend keeping a hygrometer handy as its the easiest way to ensure the humidity levels in your home are keeping both you and your pets happy and safe.