The Quietest Diffusers – Class, Capacity And Decibels

People all across the U.S. use diffusers in their homes to enjoy their favorite scents and for aromatherapy benefits. However, when some diffusers are turned on, they make a continual annoying humming noise that can disrupt sleep. Fortunately, a number of diffuser manufacturers also produce quiet models.

A diffuser is regarded as quiet if it produces less than 40 decibels (dB) of noise. Diffusers that do not use a fan, such as ultrasonic are often quieter than those with a fan, similarly a diffuser set on a low misting speed are often quieter than higher speeds. Some whisper-quiet (<30 dB) diffusers are the Asakuki (15 dB), HLS ultrasonic (23 dB), and FrapCekre (23 dB).

This guide will go over what makes a diffuser quiet and then take you through the quietest 10 diffusers available, highlighting if they are suitable for bedrooms and their unique characteristics and capacity.

What qualifies a diffuser to be quiet

There are different factors that contribute to a diffuser being considered quiet. These factors result in some diffusers producing a substantially loud noise level during operation, while others are ultra-quiet.

These factors include:

  • Misting speed settings.
  • Class (or type) of diffuser.
  • Resultant noise decibel level.

1. Misting speed settings. 

Diffusers feature misting speeds. Most diffuser models have low, medium, and high misting speed settings that are programmable based your preferences. Various reasons can determine the desire for a certain misting speed, such as existing odors in the space, the size of the space, or even the quality of the essential oil used.

When a diffuser is set on a high misting speed, it is most likely to produce more noise than when it is set to a low misting speed. Unfortunately, even at a low misting speed, certain diffusers will still emit noise beyond 60 decibels, which is as loud as a conversation and certainly loud enough to disrupt sleep.

2. Diffuser Class.

There are different classes (or types) of essential oil diffusers available, including:

  • Ultrasonic diffusers.
  • Nebulizing diffusers.
  • Heat diffusers.
  • Evaporative diffusers.

Each of the diffusers listed above works well with essential oils and is suitable for aromatherapy. However, as is customary, everything has both positive and negative aspects. The diffusers mentioned above have their own set of advantages and disadvantages, and in this case, we’re talking about diffuser noise levels.

Usually, nebulizing diffusers are louder than the other types of diffusers. That’s because they only use essential oils, which can be heavier or thicker at times, and require a continuous air flow to disperse the oil into the air as tiny droplets.

Evaporative diffusers are typically the most quiet – however, they are also the least efficient at dispersing the aroma of essential oils throughout a space. Ultrasonic and heat diffusers strike the right balance between quietness and effectiveness.

3. Resultant noise decibel level.

During operation, a diffuser’s noise production typically ranges from very quiet to very loud. A diffuser’s noise level is measured in decibels (dB), and each device has its own dB value that varies depending on the misting speed setting and type of diffuser.

You can utilize the noise decibel range to better grasp what a quiet diffuser is. The term “silent diffuser” refers to a diffuser with a low decibel output. That is to say, a diffuser with a low decibel range of 20 to 30 dB is considered a silent or whisper-quiet diffuser. Any decibel level higher than 60 dB is considered loud.

Here is a run down of decibel values with a related sound to help you choose the right diffuser for you.

Noise levelExample sound
10 dBNormal breathing
20 dBTicking watch
30 dBSoft Whisper 
40 dBGentle rain
50 dBRefrigerator hum
60 dBNormal conversation
70 dBWashing Machine
80 dBCity Traffic
90 dBMotorcycle

The 10 Quietest Diffusers

There are so many diffusers available today, but most are not quiet. Here is a detailed guide to the 10 quietest diffusers available.

Each diffuser’s coverage area and decibel rating are listed in the specifications section, so be sure to choose one that fits your needs and the size of the room you wish to disperse during purchase.

1. PureSpa 3-in-1 Oil Diffuser

PureSpa by pure enrichment is a 3-in-1 ultrasonic cool mist diffuser with a powerful mist output that can also be used as a humidifier to relieve dry air symptoms, including dry lips, nose, and throat, by adding humidity to the interior air. The diffuser has a low decibel level that produces ‘whisper-quiet’ operational noise (20-30 decibels), so it won’t wake you up as you sleep, meditate, or work.

The model has a 2-liter water capacity and can run for up to 22 hours on high Mist mode and 50 hours on low Mist mode. The diffuser can cover up to 350 square feet of space, making it ideal for small to medium spaces.

The diffuser has seven color-changing LED lights that provide a calming ambience and a mild night light glow, which helps to improve your mood and relieve anxiety.


  • Easy to use and clean.
  • Small and portable.
  • 7 color-changing lights.
  • BPA-free.
  • Affordable.
  • Features a powerful mist spray.


  • Requires regular cleaning as it features a humidifier component.

2. ASAKUKI 300ML Essential Oil Diffuser

The ASAKUKI essential oil diffuser has a water tank capacity of 300 ml. This brand is made in such a way that it can also serve as a humidifier. It’s an exceptionally low-noise diffuser with a noise level of just 15 decibels. As a result, it’s a good diffuser for the bedroom because it won’t disturb the user’s sleep even if it’s left on all night.

The device also has 7 different LED light colors that may be utilized as lights or turned off entirely by the user at night. It offers multiple timed settings as well as a safety auto-switch that keeps it from overheating if the water runs out.


  • Quiet operation device.
  • Can be used as a night light.
  • Automatic shut-off feature.
  • Easy to use, refill and clean.

3. ARVIDSSON Ultrasonic Cool Mist Diffuser

The ARVIDSSON is an ultrasonic cool mist diffuser with noise levels as low as 25 decibels at low fan speeds, ensuring that even light sleepers are not disturbed during their cool night sleep. As a result, it’s a good choice for the bedroom, even if you have a child, without the worry of the device waking it up from its sleep.

The brand is built entirely of iron and has a 500ml capacity, allowing it to last for 10-15 hours on a single charge. It also comes with four mist timers that may be customized to the user’s liking.


  • Quiet operation device.
  • BPA-free.
  • Automatic shut of feature.
  • Pets and kids-friendly device.
  • Easy to use and clean.
  • Durable.
  • Can be used as a night light.


  • Some reviewers complain about water leakage.

4. FrapCekre Essential Oil Diffusers

The FrapCekre is a 500 ml ultrasonic essential oil diffuser which is among the quietest diffusers with a low noise decibel range of as low as 23 decibels. The essential oil diffusers come with six 10ml bottles of tea tree, lavender, eucalyptus, orange, peppermint, and lemongrass essential oils.

The diffuser comes in seven distinct light hues to fit the demands of the user. Each color includes a bright and dim setting, and the user can choose from seven different hues. It’s also possible to cycle through 14 different colors (bright or dark) or stick to a single hue.

With a 500ml water tank, the brand can disperse a room for up to 15 hours of operating time on a single fill. A user can also select from four timer settings (ON/1H/3H/6H).


  • Quiet operation diffuser.
  • Easy to use.
  • Automatic shut-off device.
  • Can be used as a night light.

5. InnoGear Diffusers for Essential Oils

The InnoGear diffuser is an ultrasonic essential oil diffuser with a low noise decibel range of 25 decibels that is ideal for the bedroom. It comes with a 300ml water tank, and a strong mist output spray for quick room dispersion.

Color-changing lights are also available, which may be customized to the user’s tastes. Color changing, one color fixed color, bright, dim, or off modes are all options for the light.

The brand also has a timer that can be set to ON, 1H, 2H, or 3H.


  • Quiet operation diffuser.
  • BPA-free.
  • Easy to use.
  • Auto shut-off feature.
  • Can serve as a night light.

6.  HLS ultrasonic essential oil diffuser

The HLS is an ultrasonic essential oil diffuser that also functions as a humidifier to alleviate the symptoms of dry skin, nose, and throat caused by dry air. The diffuser has a quiet noise decibel range of as low as 23 decibels, making it ideal for use in the bedroom without the stress of bothersome noises disrupting your sleep.

This essential oil diffuser comprises an oil set that includes the most popular wood grain essential oil diffuser as well as the top 10 pure essential oils, allowing it to diffuse a greater area.

With a single fill, it has a capacity of 550 ml and a continuous runtime of 10 hours. It also has four built-in timer settings that the user may employ depending on their needs and an automatic shut-off option that allows the diffuser to stop off if it runs out of water.


  • Quiet operation device.
  • BPA-free.
  • Automatic shut-off feature.
  • Can cover large rooms.
  • Easy to use and clean.


  • Shorter run time.

7. Everlasting Comfort 

The Everlasting Comfort is a cool mist essential oil diffuser that can also serve as a humidifier with a noise decibel range of as low as 30 decibels, making it an ideal diffuser for the bedroom. Because it is silent, the user will be able to utilize it while sleeping without waking up due to distracting background noises.

It also has an adjustable mist output level and a 6-liter tank, which lasts for longer periods of time with just a single fill. The brand can run for up to 50 hours of operation in 500 square foot rooms, making it suitable for medium and large rooms.


  • Quiet operation device.
  • Easy to assemble, use, and clean.
  • Suitable for large rooms.
  • Long-running time.
  • ETL certified.
  • Automatic shut-off feature.


  • You cannot add in essential oils directly when using it as a diffuser.

8. Mooka essential oil diffuser and humidifier

Mooka is a humidifier that doubles as an essential oil diffuser. It’s a whisper-quiet diffuser that makes less than 28 decibels of noise.

The device has a waterless auto-off feature with a red LED light to alert the user if it runs out of water while in use.

It also contains a 180-degree nozzle for managing high/low mist if the user needs to change the misting speed settings, as well as a 7-LED color-changing feature that may be utilized as lights in the dark.

The brand is capable of diffusing an area for up to 21 hours of continuous operation in low mist mode.


  • Quiet operation.
  • BPA-free.
  • Automatic shut-off feature.
  • Easy to use, refill and clean.

9. Exqline 1500ml Large Essential Oil Diffuser.

Exqline is a humidifier that may also be used as an essential oil diffuser. With a noise decibel range of 35 decibels, it is one of the quiet diffusers.

The brand comes with three mist modes that can be adjusted and a 270° rotatable knob that can be used to vary the humidity level depending on the user’s demands. It is appropriate for small to medium-sized rooms because it is designed to humidify and disseminate the air in places up to 325 square feet with a 450 square foot aromatherapy smell coverage area.

The diffuser can diffuse areas for up to 12 to 14 hours at the highest mist level, and roughly 22 hours at the lowest mist level in a single fill.


  • Quiet operation device.
  • BPA-free.
  • Long-running time.
  • Auto shut off feature.


  • It’s prone to leaking.
  • Can only use water-soluble essential oils.

10. Aromatherapy Essential Oil Diffuser

The Aromatherapy essential oil diffuser is a low-noise ultrasonic cool mist diffuser that also serves as a humidifier with a decibel rating of 30 decibels.

The 500 ml water tank will provide 12 hours of constant aroma with a single fill. A timer is also included with the diffuser. All the user has to do is choose from one of the timer options: 1 hour, 4 hours, 8 hours, or continuous, and the diffuser will turn off after the specified time. 


  • Quiet operation device.
  • Automatic shut off feature.

Are there any silent diffusers?

Diffusers that produce fewer than 20 decibels of noise are considered silent diffusers as they produce a noise level equivalent with breathing. While diffusers that generate 20 to 30 decibels of noise are considered whisper-quiet. All diffusers generate some noise during operation, so none are truly ‘silent’.

The ASAKUKI essential oil diffuser is a ‘silent diffuser’ producing just 15 decibels of noise, while the diffusers by ARVIDSSON and InnoGear are whisper-quiet generating an average of 25 decibels.


Silent diffuser (15 dB)


Whisper-quiet diffuser (25 dB)


Whisper-quiet diffuser (25 dB)

Do ultrasonic diffusers make noise?

During operation, an ultrasonic diffuser makes a mild humming noise. The noise level is minimal and usually less than 60 dB. However, ultrasonic diffusers can generate loud, irritating noises indicates an underlying issue such as lack of water, a malfunctioning diffuser, or high mist speed.

Plentiful Air has detailed troubleshooting information for when diffusers are not working properly available here.

Are diffusers supposed to make noise?

During operation, a diffuser will usually create noise. The motor and fan strength will provide a background humming noise depending on the misting speed settings. On a low fan setting, a diffuser can produce noise as low as 20 decibels or as loud as 60 decibels on a high misting speed level.

Nebulizing diffusers generally create the most noise, while ultrasonic are often the quietest.

Russell Singleton

Russell holds a Bachelor of Science (Environmental and Marine Geoscience) with Class I Honors. He is currently completing his doctorate in science and is passionate about all earth processes, especially isotope geochemistry and paleohydrology.

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