Best Ultrasonic Cool Mist Humidifier Reviews 2021

If you’ve shopped for a humidifier before, you’ll know at least a few things about ultrasonic cool mist humidifier models. Mostly designed for single rooms or personal use, the units deliver cool moisture to the home, with very few drawbacks. 

“It really cranks out moisture,” one user recently said on a review site. “You can visibly see the moisture coming out.”

Users are just as impressed with the low noise levels. 

“The best part is that you get reliable humidification without the noise often associated with other types of humidifiers,” another user wrote on social media. “They are just so quiet.”

In hurry?  Here’s a table of the best ultrasonic cool mist humidifier that have been vetted by our experts.

The Best Ultrasonic Cool Mist Humidifier Comparison Table

Last update on 2024-05-30 / Affiliate links / Images from Amazon Product Advertising API

What is an Ultrasonic Cool Mist Humidifier?

To start with, there are three broad ways to categorize humidifiers including;

  • Mode of operation
  • Size
  • Temperature of the mist. 

Ultrasonic humidifiers are a subtype under the mode of operation where we also have vaporizer humidifier, evaporative humidifier, and whole-house models

The name cool mist humidifiers comes from the fact that they produce cool moisture unlike other humidifiers such as steam vaporizers that produce warm moisture. 

How does an Ultrasonic Humidifier Work?

Ultrasonic humidifiers use a special technology known as ultrasonic vibration to break down water molecules into a fine mist. The units typically include a reservoir of water and a high frequency vibrating diaphragm. Interestingly, the vibration is so high that it’s beyond the range of human hearing (thus the name ultrasonic). 

These vibrations help to break down water particles into microscopic droplets. And once these droplets are produced, they are dispersed into the air. There is no heating of water or moisture at any point. Therefore, the moisture produced and distributed throughout the house is cool. 

Pros of Ultrasonic Humidifiers

There are many advantages of investing in an ultrasonic humidifier. The following are just a few benefits of these appliances;

  • Generate extremely fine mist

This is arguably one of the biggest advantages of ultrasonic humidifiers over other types of humidifiers. The ultrasonic vibrations produce an extremely fine mist, resulting in a refreshing indoor atmosphere.

  • They are very quiet

Another major perk of ultrasonic humidifiers is the noiseless operation. Some ultrasonic humidifiers produce less than 20 decibels, which is quieter than the most silent TV sets. Evaporative humidifiers, comparably, can produce up to 50+ decibels. The low noise levels make them the best humidifiers

  • No wicks or filters

Most humidifiers depend on a wick and filter to break down water into mist and remove dirt particles from the water. The majority of ultrasonic humidifiers have neither. Instead, they depend on the ultrasonic vibrations to break down water. 

  • Flexible applications

Ultrasonic humidifiers come in a wide range of sizes and designs making them flexible for various types of applications. The smallest models, including bottle and travel humidifiers, for instance, are great for personal use. Larger console models, meanwhile, can be used for whole room humidification. 

Downsides of Ultrasonic Humidifiers

The two major drawbacks of ultrasonic humidifiers are lack of a blower system and white dust. And since there’s no blowing in ultrasonic humidifiers, cool air may not travel far enough. This explains why ultrasonic humidifiers are best suited for personal use. 

White dust is another colossal menace. In the process of humidifying, ultrasonic humidifiers also pass off minerals in the form of white dust. The main cause of white dust is the lack of filtration. 

Though not a health hazard, white dust may not be a pleasant sight. The dust makes the home untidy as it settles on furniture and other appliances. One way to minimize white dust is by using distilled water or demineralization cartridges.

 Cool Mist Humidifier Vs Warm Mist Humidifier

Cool mist humidifiers, meanwhile, derive most of their advantages from the fact that they can’t burn you, your family, or pets. Since they don’t heat up, kids who accidentally touch the units during operation are under no risk of burns at all. Not to mention that because the moisture coming out of the nozzle is cool, people sitting close to the humidifier don’t have to worry about vapor burns.

This is completely different from warm mist humidifiers that involve heating. And burning is an ever-present risk as the humidifier’s parts may get hot or you can suffer burns from the hot vapor coming out of the nozzle.

The single drawback of cool mist humidifiers, however, is that they don’t add warmth to your indoor air. Indeed, they may make the indoors feel slightly colder as the stream of cold moisture enters the space. They are, therefore, best during the heating season. 

Ultrasonic vs. Evaporative Humidifiers

Ultrasonic humidifiers are often contrasted to evaporative humidifiers. The two are different in several ways, including;

  • Mode of operation

The first and most crucial difference between ultrasonic and evaporative humidifiers is their mode of operation.. While ultrasonic humidifiers depend on a vibrating diaphragm to break down water into mist, evaporative humidifiers, on the other hand, use a wick filter. The wick (which often doubles up as a filter) helps to draw up water from a reservoir. A fan system then blows the water in the wick to break it down into fine moisture particles.

  • Filter vs. no filter

 As earlier mentioned, evaporative humidifiers have a filter that helps to remove dirt particles from the water. Some HEPA filters used in modern humidifiers can remove up to 99.97% of waterborne particles. As a result of the filtration, evaporative humidifiers don’t produce the white dust common in ultrasonic humidifiers. Though a few ultrasonic humidifiers have filters too, most don’t.

  • Blower vs. no blower

Evaporative filters also have blower systems while ultrasonic humidifiers don’t. The blower system in evaporative humidifiers serves two purposes. First, it plays a key role in breaking down water particles into moisture. Secondly, it helps blow and distribute the resulting water vapour throughout the room. 

Best Ultrasonic Cool Mist Humidifier Reviews (Updated List)

Let’s begin by reviewing some of the best ultrasonic cool mist humidifiers available today. The following are six of the top ultrasonic cool mist humidifiers at the moment. Check out for the size of the tank and auto-control features. 

1. Pure Enrichment MistAire 1.5L Ultrasonic Cool Mist Humidifier

Pure Enrichment® MistAire™ Ultrasonic Cool Mist...
  • INSTANT DRY AIR RELIEF: Ultrasonic cool mist technology safely and quickly moisturizes dry air for up to 25 hours of continuous operation in medium to large rooms up to 250 square feet. Powerful mist output with high and low settings makes this humidifier ideal for bedrooms, baby nurseries, office, and indoor plants.
  • YEAR-ROUND COMFORT: High and low-speed settings combined with a 360° mist nozzle help you consistently balance and regulate the humidity in your home all year long for relief from congestion, coughs, cold-like symptoms, allergies, dry skin, and sinus issues
  • ENCOURAGE RESTFUL SLEEP: Easily run the humidifier overnight to maintain a healthy humidity level in your space. The optional night light offers a soothing glow while the whisper-quiet operation ensures you can sleep peacefully without any disturbance.
  • EASY-FILL TANK & AUTO SHUT-OFF: The sleek and transparent 1.7 liter water tank is easy to fill right from your kitchen or bathroom sink and the compact design doesn’t take up too much tabletop space. Plus, the automatic shut-off feature turns the humidifier off when the water level is low or the tank is removed.
  • 5-YEAR WARRANTY: This BPA-free humidifier comes with an AC power adapter, disk cleaning brush, and Pure Enrichment’s guaranteed 5-Year Warranty. Our customer support team provides quality service and peace of mind to millions worldwide all from a brand you can trust.

Last update on 2024-05-30 / Affiliate links / Images from Amazon Product Advertising API

Manufactured by Pure Enrichment, the MistAire is a beautiful ultrasonic humidifier with a white base and a see-through tank. The transparent container allows you to see the water level in the tank so you can know when it’s time for a refill. And the 1.5-litre tank lasts about 16 hours of continuous use. 

The MistAire’s High and Low-speed settings make it easy to adjust the rate at which moisture is released into your room. Even better, you can also adjust the nozzle to change the direction you want to the mist to go. The unit comes with optional night lights that offer a soothing glow if you want to use the humidifier at night. An automatic switch, meanwhile, keeps track of the water level and goes off when the level is very low. And the switch also goes off if the tank is removed. 

The MistAire’s package includes a humidifier, AC power adapter, disk cleaning brush, and a user manual. Pure Enrichment offers a 2-year warranty on the product. 


  • Easy-to-fill water tank
  • 360-degree mist nozzle
  • 16 hours of continuous use
  • Lightweight (1.75 pounds)


  • Requires a bit of assembly to prevent leaking
  • Works best in smaller rooms (150 sq. ft. or less)



2. Crane Drop Filter-Free 1 Gallon Ultrasonic Cool Mist Humidifier 

Crane Ultrasonic Cool Mist Humidifier for Bedroom,...
  • LARGE ROOM HUMIDIFIER: The Crane Drop Ultrasonic Humidifier features an easy-to-clean, detachable tank that holds one gallon of water to humidify bedroom, nursery, or indoor spaces up to 500 square feet for 24 hours
  • ADJUSTABLE HUMIDITY: This air humidifier features variable controls to set optimal humidity levels when used as a plant humidifier, baby humidifier, bedroom humidifier, or as small humidifier for the office
  • SOOTHE SEASONAL ALLERGIES: Add humidity to your dry living spaces and pair with relaxing steam inhalers that help fight cold and flu symptoms all year round and make wellness a priority
  • AUTO-SHUT OFF: Each small humidifier has an automatic shut-off safety feature
  • DROP SHAPE COLLECTION: We offer a collection of air humidifiers, humidifiers for women, men, and kids, and evaporative humidifiers in a range of colors to find the right large or small humidifier for your home, nursery, office, or bedroom

Last update on 2024-05-30 / Affiliate links / Images from Amazon Product Advertising API

Featuring an award-winning design and top-rated performance, the filter-free Crane Drop humidifier is made from antimicrobial materials These materials are well known for reducing mould and bacteria growth by up to 99.96%

Filter-free humidifiers tend to have issues with mineralized water hence we encourage the use demineralization cartridges to trap any dirt. The cartridges can be purchased separately. Alternatively, you can use distilled water. This noiseless unit has a removable 1-gallon tank that fits under most bathroom sinks for easy refilling. When full, the tank can run continuously for 24 hours. 

The Crane Drop is designed for spaces up to 500 square feet and features an automatic shut-off sensor that cuts power when the tank runs dry. Other features of the Crane include whisper-quiet operation, a 360-degree lid to help you direct the nozzle, and incredible energy efficiency. Last but not least, it’s a 120-volt unit and weighs 4.5 pounds.


  • Filter-free design
  • Auto shut-off sensor
  • 24 hours of continuous use
  • Whisper-quiet operation


  • Holds only a single gallon of water



3. Everlasting Comfort Ultrasonic Cool Mist Humidifier (6L)

Everlasting Comfort's Cool Mist Humidifiers for...
  • COLD MIST HUMIDIFIERS FOR BEDROOM: This large capacity humidifier from Everlasting Comfort has a 6L water tank and offers up to 50 hours of continuous use. It's one of the best cold mist humidifiers for bedrooms and large rooms.
  • LARGE ROOM HUMIDIFIERS FOR HOME: Our cool mist humidifier works perfectly as a room humidifier for bedroom large or small, featuring an ultra-silent design. This wonderful vaporizer humidifier ensures a quiet, easy, and clean breathing, adding to the comfort of your home.
  • EASY TO CLEAN HUMIDIFIERS: This air humidifier for bedroom stands out among large humidifiers for home due to its slim and large water tank that is easy to maintain and clean. This allows for efficient use, clean air and less frequent refills of our cool humidifiers for bedroom.
  • HUMIDIFIERS WITH ESSENTIAL OILS: Our cool mist humidifier is equipped with an automatic shut-off feature for safety. It includes an essential oil tray for adding your favorite aromas, making it more than just a cool humidifier for bedrooms.
  • LONG LASTING HUMIDIFIERS: Not only does our vaporizer humidifier function as a large humidifier for home and bedrooms, its adjustable motor and 360-degree nozzle disperse a cool mist for 22 to 50 hours, making it one of the top fill humidifiers for bedrooms.

Last update on 2024-05-30 / Affiliate links / Images from Amazon Product Advertising API

If you’re looking for a large capacity humidifier for personal use, the Everlasting Comfort would be a great option. Featuring a 6-litre (1.6 gallons) tank with a super high mist output rate of 9oz (equivalent to 270ml/hour), the humidifier can serve upto  500 square feet space comfortably. When full, the tank can run for 50 straight hours or about six nights of sleep. 

The 360-degree rotating nozzle and fully adaptable mist and steam output knobs allow you to control the humidification process. Besides, the unit has an auto-shutoff sensor that automatically turns off the humidifier if the water level in the tanks is very low or whenever the tank is removed. It’s also perhaps noteworthy that this humidifier doesn’t need a filter. However, it is recommended that you use distilled or demineralized water since tap water contains a lot of minerals.

The Everlasting Comfort features an essential oil tray where you can add your favourite essential oils for a much soothing experience. A fan inside the humidifier helps to circulate the oils into the mist. This unit weighs 4.2 pounds and comes with a 2-year manufacturer’s warranty. 


  • A large, 1.6-gallon tank
  • High mist output (270ml/hour)
  • Works for 50 hours straight
  • Essential oils tray included


  • No handles to carry the tank
  • Refills from the side



4. TaoTronics Cool Mist Humidifier with Humidistat (4L)

TaoTronics Humidifiers, 4L Cool Mist Ultrasonic...
  • 4L Tank Capacity, Works for All Night: Over a gallon of water lasts for 12-30 hour working time on a full tank; designed to humidify the air in rooms up to 10-30 m² / 107-322 ft², bedroom, nursery, office and so on
  • Informative LED display: Built-in Humidistat tells you the current RH; Easily choose between three mist levels; Set your desired humidity level, 40-60% is recommended
  • Nightlight & Sleep Mode: Choose to turn on the nightlight, or enter sleep mode to shut off LED screen for a discreet sleep at night
  • Safe to Use: Automatically shuts off when water runs out; Microporous cartridge filters the water from micro-organisms and bad odor, we recommend you change filters every 4-6 months
  • Please do NOT use with essential oils, which will damage the machine and cause leakage problem.

Last update on 2024-05-27 / Affiliate links / Images from Amazon Product Advertising API

Another majestic personal ultrasonic cool mist humidifier with all the bells and whistles, the TaoTronics comes in a rectangular design with three different colours, i.e. white, black, and grey.

The 4-litre (1.06-gallon) humidifier is incredibly silent at just 38 decibels, making it perfect for bedrooms and baby rooms. The tank, when full, lasts 25 to 30 hours, or approximately three nights. It’s designed for rooms up to 322 square feet, and features informative LED display lights, a built-in humidistat, and three mist settings, including a Night & Sleep Mode. 

This TaoTronics turns off automatically if the water level runs low. It has a micro-porous filter, which should be replaced every 4-6 months. The humidifier weighs 3.25 pounds. Do not use it with essential oils. 


  • Micro-porous filter cartridge
  • Built-in handle
  • Auto-shutoff
  • Less than 38 decibels 


  • It’s a bottom fill model



5. ONSON 2019 Humidifier, 4.5L Ultrasonic Cool Mist Humidifier

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The 4.5-litre (1.2-gallon) humidifier can run continuously for 15 to 30 hours, depending on the setting. It has three mist settings – low, medium, and high, so you can adjust to your liking. Informative LED lights tell you which setting is in use while a built-in humidistat signals if you’re generating enough humidity. 

The humidifier runs noiselessly at less than 30 decibels. The low noise levels make it an ideal option for bedrooms and office use. Built-in timers allow you to preset the unit to run for a predetermined period. The timer also cuts off the power supply when the water in the tank is used up or when excessive humidification is detected. 

The ONSON is a top fill model that makes refilling effortless. It weighs 3.45 pounds and is designed for spaces up to 480 square feet. Unlike most ultrasonic humidifiers, it features a steel mesh filter that helps to remove water borne particles to minimize white dust production. 


  • Low noise operation (less than 35 decibels)
  • High tank capacity (4.5 liters/1.2 gallons)
  • Great for medium-sized spaces, up to 480 Sq. Ft.
  • Three mist modes for ideal comfort


  • It’s one of the higher-priced options
  • No carry handles 



6. PureGuardian H4810AR Ultrasonic Warm and Cool Mist Humidifier

PureGuardian H4810AR Ultrasonic Warm and Cool Mist...
  • WARM & COOL MIST HUMIDIFIER: The PureGuardian H4810AR ultrasonic cool mist humidifier guards against dry air in the home, perfect for those with colds, allergies and dry skin; The easy fill 2 gallon tank is ideal 600 square feet rooms and runs up to 120 hours
  • LOW WATER INDICATOR & AUTO SHUT-OFF: When the unit is low on water the Refill LED on the front panel will light up, and the unit will shut off. Simply add more water to continue use. Unit will automatically resume running when water tank has been refilled
  • AROMATHERAPY TRAY: The aromatherapy tray option helps create a relaxing environment with your favorite essential oil; Oils are not included; Create a better home environment and optimize your comfort with an ultra-quiet, soothing cool mist
  • ADDITIONAL FEATURES: The humidifier is equipped with the option for warm or cool mist and 3 speed settings; a low water indicator light lets you know when it's time to refill the water tank; It also features a soft glow night light and a 12-hour timer
  • PURE GUARDIAN: By Guardian Technologies offers a full range of small appliance based solutions for happier and healthier lives at home, focused on creating powerful, safe and innovative technologies to help facilitate healthier, happier home environments; Input voltage: 120v 60hz

Last update on 2024-05-30 / Affiliate links / Images from Amazon Product Advertising API

Finally, the most expensive product on this list and also one of the most user-friendly humidifiers you can buy today, the PureGuardian H4810AR is simply majestic. A solid opaque white base and translucent blue tank that forms the top half give the unit a striking appearance, with the visible control panel to the front completing a stunning design.

This humidifier is by far the largest on our list, boasting a 2-gallon tank. The tank, when full, can run nonstop for 120 hours. Inside the humidifier is what’s known as Silver Clean Protection, this technology helps to fight the growth of mould and mildew on the internal surfaces of the tank. An optional aromatherapy tray is available if you’d like to have a few drops of essential oils to create a relaxing atmosphere. 

The control panel has several functions, including settings to control the level of humidification. There are three mist settings in total. In addition, the panel also features a low water indicator that lets you know when it’s time to refill the tank. Soft-glow night lights and a 12-hour timer are the other features accessible from the control panel. The 5.5-pound humidifier comes with a 5-foot long cord.


  • Large 2-gallon tank
  • Works for 120 hours nonstop
  • Optional aromatherapy tray
  • Auto shut-off switch
  • Silver Clean Protection technology


  • Most expensive on this list
  • Heaviest unit on this list




Factors to Consider when Buying a Cool Mist Ultrasonic Humidifier

If you decide to buy a cool-mist ultrasonic humidifier, there are several factors you’ll need to consider. These include;

  • Size

Humidifiers come in many sizes. Some are large enough to serve an entire house, while others are smaller models designed for personal use. Ultrasonic cool mist humidifiers are mostly designed for single rooms and personal use. Still, you’ll need to decide what size best suits the intended application.

  • Tank size

The tank (or reservoir) size is also very important. How many litres of water can the tank hold? The larger the tank, the less frequently you’ll need to refill it. Some humidifiers also allow users to buy larger tanks separately. That’s something else you want to consider. 

  • Noise rating

Although all ultrasonic cool mist humidifiers are comparably quieter than other types of humidifiers, the noise ratings vary. Some are rated at as low as 20 decibels or less while larger ones are rated in the 25-40-decibel range. Make sure to check the rating before making a decision. 

  • Warm/cool mist combo?

Yes, there are a few ultrasonic humidifiers that double up as warm mist and cool mist models. The majority are first and foremost cool mist humidifiers. But, a setting is available that when flipped instructs the unit to heat the water. So, do you want a 100% cool mist unit or a combo model?

  • Automated settings

Some advanced humidifiers are also designed such that you can pre-program the humidification process. Some, for instance, have flue, dry skin, and allergy settings to effectively meet your needs throughout the year. Others can also be set to run for a predetermined period and go off once that period elapses. 

  • Presence of a humidistat

Finally, the best humidifiers have a humidistat. As we mentioned earlier, a humidistat helps a humidifier keep accurate track of relative humidity. 

Humidifier FAQs

      • Do cool mist humidifiers cause mold?

Yes, mold remains of the key challenges faced by people who use cool mist ultrasonic humidifiers. The problem is often worsened by the fact that ultrasonic humidifiers don’t have filters. 

      • Can cool mist humidifiers make you sick?

Yes. Although they may help ease symptoms of cold and other respiratory diseases, when  not properly maintained and cleaned, cool mist humidifiers can harbor bacteria, allergens, mold, and other harmful microorganisms. And because the humidifiers don’t have filters, all these harmful microorganisms often find a way into your indoor air. 

      • Is it good to sleep with a humidifier every night?

The short answer is yes. Sleeping with the humidifier overnight comes with a series of benefits, including better sleep, reduced risk of infections, and relief from congestion. It is, however, important to watch out for over-humidification. Also, beware that the water tank can run dry, creating a fire risk. 

      • Is cool mist humidification good for coughs?

Yes. Unending coughs during the winter period may be caused by allergies. Dry indoor air can also cause an itchy throat which may cause coughing. Humidifying your home can help alleviate some of the symptoms. Remember, though, that humidifiers aren’t a substitute for medical treatment.

      • Does a cool-mist humidifier help with congestion?

Yes. Congestion during the winter weather is often caused by blocked sinuses. When there’s very little moisture in the air, lubrication in the sinuses is affected. Humidifiers help boost lubrication, thus easing congestion. 

      • Does cool-mist humidifier make a room cooler?

Not necessarily. Cool mist humidifiers produce a cool mist, yes. However, the cool mist won’t necessarily make your room cooler, especially if you’re using a heater simultaneously. The people seated close to the unit might, however, feel a slight breeze. 

Final Thoughts

The dry winter weather isn’t good for your health. With very little moisture in the air, the weather can cause serious problems, including allergic reactions, an itchy throat, itchy eyes, and cold symptoms. The best ultrasonic cool mist humidifier can help prevent or alleviate some of these issues. Just remember that humidifiers aren’t an alternative to medical treatment. If the symptoms persist, seek medical treatment.

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Melanie Mavery is an aspiring HVAC technician who is fascinated by the trends and opportunities in the HVAC industry. She spends most of her day writing content on home improvement topics and outreaching to prospects.  She's always looking for ways to support HVACs!