Wednesday, December 20, 2023

The Best Ultrasonic Humidifier: Ultra Quiet, Easy to Clean & Fill

We live in New England, where the winters are cold and the indoor air is dry from the heating system. I am also susceptible to respiratory illnesses such as colds, flu, bronchitis, and pneumonia in the winter, so using a humidifier is necessary for both health and comfort.

We have found that ultrasonic humidifiers, which we prefer for reasons I'll go into below, tend to last only a few years. So, we have tried a variety of brands and models. The Levoit LV600S Smart Hybrid Ultrasonic Humidifier we purchased a month ago is our favorite by far.

Levoit LV600S Smart Hybrid Ultrasonic Humidifier
The Levoit LV600S is the New York Times Wirecutter's top pick as
The Best Humidifier of 2023. We love ours!

How to Choose a Room Humidifier

After purchasing multiple humidifiers over the years and doing a lot of product research before each purchase, we've gotten good at choosing a good one. Here are the key considerations when shopping for a humidifier.


There are four main types of portable room humidifiers we considered, which differ based on how the humidity is generated.

Warm mist humidifiers heat the water to create the vapor, i.e., steam. They're great for cold, dry winter climates like ours, and the heat cuts down on germs and bacterial contamination. We have found that they can create a lot of humidity — sometimes too much if you don't keep an eye on the moisture levels. However, warm mist units tend to be noisy, use more energy, and be more difficult to clean than cool mist models. Also, if you have children or pets, a reservoir filled with boiling water may not be the safest choice.

Cool mist units increase the humidity of the room without raising the temperature, so they're ideal for dry, warm climates. They tend to be pretty energy efficient. The units emit a humming sound that may bother some people, while others may experience it as "white noise" that is acceptable. We have found that they can be prone to developing mold and mildew and need to be cleaned more frequently than other types.

Evaporative humidifiers are a subset of the cool mist category. These units create vapor by using a fan to blow air through a moist filter, speeding up the natural process of evaporation, and that vapor is emitted or blown into the room. Like other cool mist models, evaporative humidifiers are safe for children and pets (because the mist is cool or room temperature), and are energy efficient. The filter needs to be changed regularly.

Ultrasonic humidifiers use high-frequency sound vibrations to break the water into droplets, which are then expelled into the air. These units are very energy efficient and extremely quiet, making them a great choice for bedrooms. Many models offer the option of producing cool or warm mist. They may or may not require a filter.

After having tried several types, we prefer an ultrasonic.

Size of Room

As with choosing an air conditioner or space heater, it's important to choose a model designed for rooms of a similar size to the one for which you are purchasing the unit. The power of whatever is creating the mist determines the volume of space the unit can humidify.

Reservoir Capacity

The size of the reservoir determines how long the unit can produce vapor (not how much it can produce) and, therefore, how often you will need to refill it. For that reason, it's important to make sure the reservoir is at least large enough to continue producing mist throughout the night, while you are sleeping.

I look for a large-capacity reservoir that I can fill only once or twice a day.

Ease of Filling

A top-fill reservoir is much easier to fill than a bottom-fill tank. A top-fill reservoir can be filled without removing it from the base unit, whereas a bottom-fill reservoir must be lifted off the base, carried to a faucet, and inverted under the tap to fill it. This can be messy (the water drips) and, if you have a large tank, heavy after you fill it.

Our last ultrasonic humidifier had a bottom-fill reservoir, and we hated it. The sink in our master bedroom's en-suite bathroom is old and small, and we couldn't get the opening of the reservoir under the faucet. That meant we had to carry the dripping tank to and from the kitchen.

Also, since a humidifier should only be on when the reservoir is in place, we had to remember to turn off the power, remove the tank, fill it, replace it, and turn the unit back on.

Ease of Cleaning

It's important to clean your humidifier frequently to avoid breathing vapor filled with germs, mold, and mildew. So, choosing a model that is easy to clean has become one of our top criteria.

Consider the size of the reservoir opening (can you reach inside easily?), and the size and number of corners, nooks, and crannies in the base and tank.


Consider whether you want manual or automatic controls or a choice. For example, you might want to manually set the rate at which the unit produces mist (regardless of the ambient humidity level), or you might want to set a target humidity level and let the unit automatically start and stop producing vapor as needed to maintain that humidity.

If you live in a climate where the humidity is fairly constant, manual controls are fine. However, if you live in an area with more variable weather conditions, like New England (where the saying goes, "If you don't like the weather, just wait a minute"), a unit with an automatic setting to maintain a target humidity level will be important.

Price of Consumables

Some types and models require water filters, mineral absorption pads, or other consumables, some of which may be optional (like the aroma pads for our new unit) or may depend on whether you have hard or soft water in your house.

It's important to determine which consumables, if any, are required, how often they will need to be replaced, and how much they cost, to help you determine the total cost of ownership over the expected lifetime of the product.

Customer and Expert Product Reviews and Recommendations

When my husband and I are researching products like humidifiers, we always do our due diligence. We comb through Amazon product reviews and look to expert product reviews and recommendations such as those from Consumer Reports and The New York Times Wirecutter to help us narrow our short list of candidates and finalize our product selection.

Levoit LV600S ultrasonic humidifier and filtered water pitcher
The Levoit LV600S Smart Hybrid Ultrasonic Humidifier can crank out plenty of humidity when needed, and for a long time, thanks to its powerful output and large-capacity, 6-liter water tank.

Why We Love the Levoit LV600S Smart Hybrid Ultrasonic Humidifier

After trying so many different humidifiers over the years, here are the reasons we love our new Levoit LV600S humidifier.

The NYT Wirecutter's Top Pick

This ultrasonic humidifier topped our list of candidates after we read the New York Times Wirecutter article "The 6 Best Humidifiers of 2023" and saw that the Levoit LV600S Smart Hybrid Ultrasonic Humidifier was their top pick. That was a compelling expert recommendation, and when we looked at the Amazon customer reviews for this product we were extremely impressed with the overwhelmingly positive feedback.

Hybrid Warm/Cool Mist Ultrasonic

If you're not sure which type to buy, the Levoit LV600S Smart Hybrid Ultrasonic Humidifier gives you the best of all worlds. This model defaults to cool mist, but there is a Warm Mist button that cycles through your choice of warm mist settings (low heat, medium heat, high heat, heat off).

For example, if someone is sick and has chest congestion, you can select one of the warm mist options to help them breathe easier.

The brand's "exclusive" Warm Mist mode claims to have improved mist dispersion and a powerful output: "Set at 550ml/h, the warm mist function generates temperature variation, boosting air circulation for 4× faster relief from discomfort" vs. cool mist.

There is also no risk of being scalded by hot vapor, as the mist is released at a safe temperature of 86-120 °F.

Designed for a Large Room

With its powerful 550ml/h output, the Levoit LV600S is designed to humidify an area as large as 753 square feet. 

Large Reservoir

One of the things we love about this model is the large 6-liter capacity reservoir. We keep our humidifier cranking 24/7 during the cold, dry, New England winter months, and although we top up the water daily, the tank is usually still about half full after 24 hours.

Depending on the settings, the manufacturer claims the unit can produce humidifying mist for up to 50 hours on a single tank of water.

Easy to Fill

The Levoit LV600S is a top-fill model. So, instead of having to turn off the power, remove the water tank, carry it to the sink, turn it over, unscrew the cap, maneuver it under the tap, fill it, replace and tighten the cap, carry it back to the base, and seat it properly before turning the power on again, as we did with our previous model, we can just lift the lid, top up the tank with filtered water from our Brita pitcher, and replace the lid. Easy peasy!

Easy to Clean

This is by far the easiest-to-clean ultrasonic humidifier we have owned. The large opening in the tank makes it easy to reach inside, and the interior corners of both the base and the water tank are very accessible. The cleaning brush that comes with this model is also larger than those from our previous units.

Ease of Operation

The Levoit LV600S has simple, intuitively labeled buttons on the front control panel and a large, easy-to-read, digital display (which is turned off automatically in Sleep Mode).

Automatic Humidity Control

Since we live in New England, the ability to have the unit adjust the volume of mist output automatically to maintain a desired target humidity level is essential. We love this set-it-and-foreget-it mode. However, you can also set the mist output level manually, if you prefer.

Reasonably Priced Consumables

The Levoit Replacement Mineral Absorption Pads should be replaced every 2–4 weeks depending on the hardness of your tap water. A pack of 10 costs $9.99 on Amazon at the time of this post's publication. You can also find less expensive replacement pads that claim to be compatible with this model.

The Levoit Water Filter Sponges should be changed about once a month, depending on the water hardness in your area. At the time of this article's publication, a 10-pack costs $9.99 on Amazon.

There are also optional Levoit Aroma Pads that can be used with essential oils and placed in the Aroma Box compartment at the back of the base. The mist will diffuse the aroma when the humidifier is in use. A pack of 16 costs $9.99 on Amazon as of this writing.

Extremely Quiet

At a noise level of less than 28dB, the default unheated, cool mist mode is practically silent, which we love. The sound increases when the Warm Mist settings are used to heat the water, but this model is still extremely quiet compared to our previous humidifiers.

Sleep Mode

The Sleep Mode turns off the lighted controls display and changes the mist setting from a manual mode (if applicable) to an automatic mode and uses the humidity sensor to automatically adjust the mist level to maintain 50-60% relative humidity. 

Sleep Mode also turns off the warm mist, if applicable, to reduce noise, but you can press the Warm Mist button to turn it back on if desired.

My husband can't sleep well unless our bedroom is completely dark, so being able to keep the display turned off is a great feature for us. We keep our set to Sleep Mode all the time unless we need to change a setting manually, which makes this appliance much more unobtrusive.

Minimal "White Dust"

After running our Levoit LV600S nonstop for the past month and filling it with filtered tap water from our Brita pitcher, we still haven't seen any sign of the dreaded mineral residue on our furniture or floors.


Although we have not yet needed to use it, you can set a timer to automatically shut off the unit after a preset interval (between one and 12 hours).

Memory Function

This model will remember your Mist Level, Humidity Level, Warm Mist, and Wi-Fi settings even when the unit is turned off or unplugged. It will not remember your Sleep or Timer settings, however, and the display will turn on automatically when the unit is turned back on.

Aroma Box

At the back of the base, there is a compartment called the Aroma Box. You can pull it out, put 8–10 drops of essential oil onto an Aroma Pad, place the scented pad into the compartment, and replace it. This will lightly scent the water vapor. We have not tried this yet.

“No Water” Indicator With Auto-Shutoff

If there is no water in the tank, this indicator will blink 10 times and the humidifier will shut off automatically. The indicator lights up when the water tank is removed and remains on until the tank is re-seated on the base.

Mobile App

What makes the Levoit LV600S Smart Hybrid Ultrasonic Humidifier "smart" is that it is Bluetooth- and VeSync-enabled. VeSync is a smart home app that allows you to control connected devices remotely from anywhere.
Screenshot of the VeSync smart home mobile app on my iPhone. The app lets you
control your humidifier and other VeSync-enabled devices from your smartphone.

We only started using the app this week, and it's a great option with an extremely intuitive, easy-to-use interface. It's also nice to know that we will be able to control our humidifier remotely when we travel.

The app allows also you to access additional smart functions including a sophisticated Plant Mode and is compatible with Amazon Alexa and Google Assistant for voice commands.

Sleek Design

Although appearance is less important to us than function and features when we choose an ultrasonic humidifier, this one has the advantage of looking streamlined and unobtrusive and doesn't detract from our home decor. A nice bonus!

Helpful Humidifier Tips

Optimize the Humidity Level

If you live in a climate with cold winters, keep the humidity level low enough so the mist doesn't condense on your windows (and potentially rot the wood window frames).

Consider a Standalone Indoor Hygrometer

A humidifier's built-in humidity sensor (humidistat) measures the humidity in the immediate vicinity. For a more accurate measure of the room's humidity, we put an inexpensive indoor hygrometer on the far side of the room and set the humidifier's target humidity so that our desired humidity level displays on the hygrometer.

Protect Against Possible Leaks

The only time we had an ultrasonic humidifier leak, it was the result of user error. (It had a bottom-fill tank and when we refilled and replaced it on the base, we didn't seat the reservoir correctly, so the water leaked onto the table.) So, as a precaution, we now put our ultrasonic humidifiers on an old plastic cutting board on top of a sturdy plastic 12-gallon lidded storage container. The cutting board provides a stable surface for the unit to sit on, and the interlocking flaps at the top of the crate are not water-tight, so if there is ever a leak, the water would fall through the interlocking flaps and be contained inside the crate with no risk of damaging our hardwood floors.

If you want to keep the humidifier manual and consumable supplies (e.g., filters) next to the humidifier, as we do, put them in a zippered plastic freezer bag to keep them dry and protect against possible leaks.

Use Distilled or Filtered Tap Water

If your tap water is hard, you can cut down significantly on the dreaded white mineral dust (the residue from the minerals in the water after the emitted mist evaporates) by using distilled or filtered water. We keep a Brita water filter pitcher next to our humidifier and use the filtered water to refill the reservoir.

In fact, the manufacturer of our model recommends that all users use distilled water or filtered water to fill the Levoit LV600S Smart Hybrid Ultrasonic Humidifier instead of tap water, which they say "might leave white dust and grow mold."

Give the Gift of Health and Comfort

If you know someone who lives in a cold or dry climate, has respiratory issues, or gets colds easily, the Levoit LV600S Smart Hybrid Ultrasonic Humidifier would make a great gift!

The Best Ultrasonic Humidifier: Ultra Quiet, Easy to Clean & Fill by Margaret Schindel

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Note: The author may receive a commission from purchases made using links found in this article. “As an Amazon Associate, Ebay (EPN) and/or Esty (Awin) Affiliate, I (we) earn from qualifying purchases.”


  1. I never knew there were so many different types of humidifiers. We have a cool mist humidifier that the tank has to be removed to fill. I would certainly prefer a top fill model like yours. Thanks for the excellent review of the different types.

    1. Sam, I’m glad my review is helpful to you. The top-fill feature is one of the things we love about this humidifier compared to our previous models. We run it as a cool mist humidifier unless one of us is sick.

  2. This sounds like a great choice in humidifiers. I am sure I would much prefer a unit that fills from the top and I would especially want one that is easy to clean. I have heard that humidifiers that are not cleaned properly, can do more harm than good. Thanks for the recommendation!

    1. Ms. Mouse, you are correct that cleaning humidifiers routinely is essential. That’s why choosing one that is easy to clean is so important. The top fill feature and wide lid opening help make filling and cleaning this model much easier than on other top-rated models we have owned in the past.

  3. Your humidifier review is well-timed, Margaret, as my son and I were discussing the need for one for each of our residences just recently. Dry air in the bedroom is definitely a problem. Thank you.

    1. I’m so glad, Elf! My husband and I couldn’t be happier with this model and recommend it wholeheartedly.

  4. Lots of information on these humidifiers. We have one attached to our furnace are these room ones better in your area?

    1. Mary Beth, we have never had one attached to our furnace, so I can’t compare this to that type. How easy (and convenient) is it to clean the one you have, and how happy are you with the humidity level?

  5. Thank you for your detailed review on the humidifiers. There are often so many choices with these things it can be difficult to sift through the things we need to focus on, so this is very helpful. I didn't know there were four types and there are many features to bear in mind prior to purchase. This Levoit LV600S Smart Hybrid Ultrasonic Humidifier sounds a great choice!

    1. Thank you so much for your kind words, Raintree Annie! I enjoy doing product research “deep dives” and sharing what I have learned, as well as my product recommendations, with others who might find them helpful.

  6. Margaret, you have filled in all the questions that I would have had. I like that it's easy fill and easy clean, these two things are really important to me. I will have to look into this and see if it's something we should be using as well. Thanks for a great review that answers all the questions anyone could possibly have.

    1. Olivia, I’m so glad you found my review helpful! In your Canadian climate you would definitely benefit from using a humidifier, especially in the winter. This one is so much better than any of our previous models! Easy to use, easy to clean (compared to others we’ve had), full-featured, and the option to switch from cool mist to warm mist if one of us gets sick is great.

  7. This sounds like an excellent choice. We just deactivated our very old humidifier that is attached to the furnace. It's done. I've been thinking of a stand alone unit and truly appreciate your article and having the research already done for me. Not sure if we will get a humidifier; we're going to see how the winter goes - however, I do know they're beneficial to have; important to have. Thanks again Margaret; this is a timely article for me.

    1. Barbara, I’m happy my review was timely for you. In cold Northern climates like ours, a humidifier is a valuable investment in health and comfort. If you decide to get a stand-alone humidifier, I give this one my highest recommendation!


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