The Best Ultrasonic Humidifiers for Cool Mist and Comfort

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The wintertime can not only bring cold temperatures but dry air as well. Dry air can have unbearable effects on your body, such as nose bleeds, flaky skin, and difficulty breathing.

Fortunately, there are many benefits that a humidifier provides. Using an ultrasonic humidifier can help alleviate many issues by adding moisture to the air in your home.

In this article, I’ll discuss what to look for when buying an ultrasonic humidifier. I’ll also review some of the best ultrasonic humidifiers on the market right now.

Best all-around ultrasonic humidifier

Levoit Top Fill Cool Mist Ultrasonic Humidifier

This Levoit humidifier has a smartphone app that sets it apart from other humidifiers. You can use the app to dial in the humidity level that you desire. The app also gives you updates—such as when you need to clean the humidifier

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The Levoit Top Fill Cool Mist Ultrasonic Humidifier is the best all-around ultrasonic humidifier. First of all, it has an adjustable humidistat that allows you to dial in the exact humidity level that you desire. It also has a large 6-liter tank for long operation.

There are a few things that make this humidifier stand out from the others. The best feature is that it connects to your WiFi and can be controlled with an app. The app allows you to remotely adjust humidity levels. You can even use the app to turn the humidifier on and off.

Perhaps the most underrated feature is that it fills from the top. Having a top-filling humidifier is important for a couple of reasons. First, it allows you to leave the humidifier in one place and simply bring a pitcher of water when you need to refill it. You also don’t need to fumble with removing a tank and bringing it to the sink every time you need to fill it up.


  • The smartphone app allows for remote control from nearly anywhere
  • Fills from the top so you don’t need to fumble with a tank
  • Adjustable moisture settings for precise humidity control


  • The hygrometer is not the most accurate—but still very precise

Bottom Line

The Levoit Top Fill Cool Mist Humidifier is the best all-around ultrasonic humidifier since it performs well and is very easy to use and maintain. It does its job right and is a set-it-and-forget-it kind of device.

Best ultrasonic humidifier for small rooms

Pure Enrichment Ultrasonic Humidifier

The Pure Enrichment humidifier is one of the easiest-to-use humidifiers on the market today. It has four different settings of humidification so you can dial in the right amount of humidity for your room. When running, it is so quiet that you won't even notice that it's on.

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The Pure Enrichment Ultrasonic Humidifier is a compact humidifier that is suited for use in small areas such as bedrooms or home offices. It is a no-frills device that is great for overnight use since it has whisper-quiet operation.

Our favorite feature about this humidifier is that it includes a built-in night light that is perfect for illuminating a dark room before bed or setting the mood. Cleaning this humidifier is easy since it disassembles into a few parts and includes a cleaning brush.

Filling up the Pure MistAire Ultrasonic Humidifier is simple – just remove the tank, remove the cap, and fill it up with water in your bathroom or kitchen sink. With a full tank, this humidifier will operate continuously for up to 16 hours.


  • Includes night light
  • Compact for use in small rooms
  • The tank is small enough to fill in bathroom sink


  • May leak if not properly cleaned

Bottom Line

The Pure Enrichment Ultrasonic Humidifier is ideal for humidifying small spaces. Its quiet operation is suited for bedrooms and offices.

Best ultrasonic humidifier for large rooms

Levoit 6L Ultrasonic Humidifier

The Levoit 6L ultrasonic humidifier packs a multitude of features, including a programmable humidity setting, warm and cool mist options, and a large tank. It is capable of keeping an accurate humidity level for days on end.

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The LEVOIT 6L Ultrasonic Humidifier is the biggest humidifier in our roundup and packs the most features by far. First of all, it is capable of humidifying large rooms – spaces up to 753 square feet, or about 27’x27’.

Better yet, this is the only humidifier in our roundup that has a built-in humidistat. With the humidity sensor, you’ll be able to dial in the precise amount of humidity that you desire in a space. Then the humidifier will automatically adjust its mist level to maintain your desired humidity.

Besides being able to disperse a cool mist, this humidifier is also able to disperse a warm mist as well. By using the warm mist setting, you can relieve symptoms brought on by dry air in the cold winter months. The warm mist setting also allows for greater moisture output for humidifying the largest of spaces.

This humidifier includes some convenience features as well. First, it has a remote control. You’ll be able to conveniently adjust the humidity settings without leaving your couch. You can also use the remote to set a timer so you don’t accidentally forget to turn the humidifier off.

If you enjoy aromatherapy, this humidifier also has an aromatherapy tray so you can add some of your favorite oils to disperse throughout your home.


  • Includes a humidistat for precise humidity level control
  • Includes remote control for easy operation
  • Has an automatic shutoff timer so you can set it and forget it


  • Can be tricky to reseat a full tank onto the unit

Bottom Line

The LEVOIT 6L Ultrasonic Humidifier is the full-featured ultrasonic humidifier that has everything you need and more. While it’s designed for humidifying large spaces, it can work just as well in small spaces since it will automatically adjust mist levels with its included humidistat.

Best ultrasonic humidifier with small footprint

Raydrop Cool Mist Humidifier

The Raydrop Cool Mist Humidifier has a small footprint, so you can keep it in a small space that needs humidity.

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The Raydrop Cool Mist Humidifier is a small humidifier with a large tank for continuous operation. It has a 2.5L tank that can last up to 30 hours on the lowest mist setting.

Since this humidifier has a small footprint, it is suited well for small rooms where there is not much space.

One of our favorite features of this humidifier is that it fills up from the top. Simply remove the lid and fill it up with distilled water and it’s ready to go. That means you don’t have to fumble around by removing a tank and bringing it to the sink.

If you enjoy the scent of aromatherapy or essential oils, you can add the oils directly to the water in the tank. Since the tank is translucent, you can also monitor the water level inside the tank visually.


  • Fills from the top so you don’t need to remove the tank
  • Includes aromatherapy tray
  • Large tank will allow for continuous operation


  • Moisture output is sufficient for only small rooms

Bottom Line

The Raydrop Cool Mist Humidifier is best suited for humidifying small areas for long periods of time. It can last up to 30 hours on a single tank and will automatically shut off when it’s out of water. With its adjustable dial, you’ll be able to dial in how much mist you want the humidifier to discharge into your room.

What is an ultrasonic humidifier?

An ultrasonic humidifier is a device that adds moisture to the air. It is used inside of homes when the air is dry, such as during the wintertime. By adding moisture throughout a space, they keep your home comfortable even when the weather is cold and dry.

With a comfortable level of humidity inside your home breathing becomes easier, and skin does not dry out.

Ultrasonic humidifiers are able to add moisture to the air without the use of heat, so they are safer to use than evaporative humidifiers.

How does an ultrasonic humidifier work?

Ultrasonic humidifiers work a bit differently than evaporative humidifiers. Ultrasonic humidifiers work by converting water into a fine mist by means of high-frequency vibrations.

The fine mist produced by the vibrations is blown into the air by a fan. Once the mist is propelled out of the humidifier, it evaporates and adds humidity to the air in the space.

Ultrasonic humidifiers have a tank that must be filled with water for it to work. A tank of water will last from a few hours to a few days, depending on how much you use the dehumidifier.

Ultrasonic humidifiers also have an adjustment knob that allows you to control the amount of moisture that you add to the air. Some ultrasonic humidifiers also have a humidistat that allows for fine-tuning of the humidity level in a room.

The mist droplets created by an ultrasonic humidifier evaporate into your room's air

How to choose an ultrasonic humidifier

Choosing an ultrasonic humidifier largely depends on the type of room that you need to humidify. A large open office will require a large humidifier to satisfy the room’s humidification requirements.

It should be noted that bigger is not always better, and the performance of your humidifier will depend on many factors such as temperature, pressure, and relative humidity levels.

Ultrasonic humidifier tank size

A better way to select the humidifier that you need is by the size of the reservoir, or tank.

If you will be using the humidifier in a large space, you will want a humidifier with a large tank. This may sound obvious, but you’ll want to ensure that you don’t have to refill the humidifier’s tank multiple times a day.

Likewise, if you will be humidifying a small room, then you can get a humidifier with a small tank. This will let you save a bit on your purchase, and the humidifier won’t take up as much space in your small room.

Ultrasonic humidifier filter

Another thing to consider when choosing an ultrasonic humidifier is whether the humidifier has a filter.

A filter will aid in removing dissolved minerals from the water as the humidifier runs. The result will be cleaner air and less “humidifier dust” buildup inside your home.

If you will be running your humidifier constantly, consider purchasing a humidifier with a filter to improve the air quality inside your home.

The downside is that you’ll have to periodically change the filter, and that can add to the costs of using the humidifier.

Ultrasonic humidifier water

If your humidifier does not have a filter, it’s a good idea to use distilled water instead of plain tap water when filling up your humidifier’s reservoir.

Distilled water has been treated to remove most minerals and dissolved solids, so you’ll have less dust in your air.

Some ultrasonic humidifiers have additional features that others do not have. These additional features can make or break its usefulness for your situation.

Ultrasonic humidifier features

There are a few additional features that you can find on ultrasonic humidifiers.

The additional features are not necessary, but they do make using the humidifier much easier and more convenient. I’ll go over them below.

Ultrasonic humidifier humidistat

One of the best features to have in an ultrasonic humidifier is a humidistat.

A humidistat allows you to dial in the precise amount of humidity that you desire in a space.

The humidistat works by sensing the humidity inside of a room and adjusting the humidifier’s output to maintain a precise humidity level.

The result is accurate control of humidity levels, so it is never too wet or too dry inside of your room.

Ultrasonic humidifier automatic shutoff

Another important feature is an automatic shutoff.

The automatic shutoff works by automatically turning off the humidifier when the tank runs out of water.

This is an important feature because running your humidifier without water may damage the humidifier. Automatic shutoff is a standard feature in most ultrasonic humidifiers.

Ultrasonic humidifier aromatherapy oil compartment

One other feature that some ultrasonic humidifiers have is an additional compartment for aromatherapy oils.

This is a great feature if you want to diffuse aromatherapy or essential oils into your air – then your ultrasonic humidifier can do that for you.

Ultrasonic humidifier comparison table

Tank Size:





Humidity Output:

Up to 300mL/hr

150 mL/hr

Up to 300mL/hr (Cold mist)

Up to 500mL/hr (Warm mist)

180 mL/hr

Room Size:

215-505 sqft

250 sqft

Up to 753 sqft

300 sqft






Aromatherapy Tray:





Night Light:





Benefits of using an ultrasonic humidifier

Ultrasonic humidifiers offer many benefits over using a plain old evaporative humidifier:

  • Whisper quiet. Ultrasonic humidifiers have much smaller fans than evaporative humidifiers, so they are much quieter. However, they still do make a small amount of noise, so take note if you will be using it in a quiet area, such as a living room or bedroom.

  • No filter is required. Most Ultrasonic humidifiers don’t have any filters so you won’t need to worry about changing filters. However, some ultrasonic humidifiers do include filters (more on this below).

  • Easy to clean. The operating principle of ultrasonic humidifiers is relatively simple. This means that there is less complexity and fewer parts to clean.

  • Cool mist. Since ultrasonic humidifiers work by high-frequency vibrations, there is no heating element inside of them. This means that there is no risk of burns when touching an ultrasonic humidifier. This is great for families with children.

  • Less energy consumption. Ultrasonic humidifiers consume very little electricity compared to their evaporative counterparts. This means that you’ll save money on your electric bill.

How to clean an ultrasonic humidifier

Even though ultrasonic humidifiers don’t heat water, they still need to be cleaned.

Dissolved minerals are present in all tap water, and can scale up the interior of your humidifier.

You will need to clean your humidifier at least every 3 days, and even more often if you run it constantly.

Since ultrasonic humidifiers are relatively simpler machines than their evaporative counterparts, cleaning them is quite simple.

The main goal of cleaning a humidifier is to remove any scale or mineral buildup. To clean your ultrasonic humidifier, follow these steps:

  1. Turn off and unplug the humidifier.

  2. Disassemble the humidifier. Remove the tank from the basin and drain both completely.

  3. Fill the tank half full with warm water. Add two (2) tablespoons of white vinegar. Shake or stir the tank to allow the water-vinegar solution to clean the interior of the tank.

  4. Add warm water to the basin, but not too much to allow the basin to overflow. Add two (2) tablespoons of white vinegar to the basin. Stir the water-vinegar solution to clean the basin.

  5. Allow the tank and basin to soak with the water-vinegar solution. Periodically stir or shake to allow the solution to clean and disinfect the humidifier parts.

  6. Use a soft nylon brush to scrub off any stubborn mineral buildup. Be careful not to damage any parts.

  7. After allowing the tank and basin to soak for about 30 minutes, empty the cleaning solution out of them. Rinse the tank and basin with clean water and dry it with a paper towel. Note: Do not let any of the electronic components get wet, such as the power cord.

About Your HVAC Training Shop Author

Hi, my name is Trey Lewis and I’m the founder and chief editor at HVAC Training Shop. My goal for this website is to help homeowners troubleshoot and maintain their home’s HVAC systems. Whether it’s changing an air filter, troubleshooting a blower motor, or just buying a new humidifier, I want to make sure that you’re covered.

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