What is the Difference Between a Humidifier and Diffuser?

Do you find yourself fretting over rough and dry weather that makes you curse the mornings during the colder months? Have you been using air fresheners and aromatic candles for freshening the house? Worry not! 

If you have landed here looking for the permanent solution to this problem, we have your back! In this article, we discuss everything you should know about humidifiers and diffusers, and in particular, the differences between them.

What is the Difference Between Humidifiers and Diffusers?

Humidifiers are electrical devices that balance low moisture in the air. The device prevents dry air from entering the lungs by releasing moisture into the air. 

Contrary to that, diffusers are a medicinal device that uses essential oils and spreads their fragrance across the room. These essential oils are made from freshly extracted plants with a strong fragrance to aid mental and physical health. 

In simple terms, humidifiers increase moisture, while diffusers create an aroma in the home using the natural oils of medicinal plants. 

Benefits of Humidifiers

  • Moisturized air: Humidifiers can complement a great skincare routine! Particularly in winters, humidifiers help to get rid of dry air, which helps to keep our skin moisturized.
  • Prevent skin diseases: Dry weather can cause certain skin reactions. Humidifiers prevent dry air from causing our skin to develop rashes, flakiness, bleeding, or other uncomfortable conditions like eczema or psoriasis. 
  • Reduces winter cold: During winters, the surrounding cold air makes it difficult to create warmth inside the house. The body gets exposed to diseases associated with cold temperatures. Humidifiers help the body fight against the cold, viruses, pneumonia, sore throat, and even asthma and other respiratory issues. 
  • Helps improve sleep quality: With reduced moisture, the body becomes vulnerable to sensitive weather that can disturb our sleeping patterns. The use of humidifiers promote sleep and help in improving breathing while we sleep.
  • Blocks static electricity: The use of humidifiers to moisturize the air helps to reduce those pesky static electricity shocks. 
  • Keeps wooden furniture in shape: If the indoor moisture content has a relative humidity between 40-52%, wooden furniture will have average moisture of 8-9%. Humidity below 40% is likely to cause your furniture to gradually shrink and develop cracks. So, humidifiers can help protect your wooden furniture, wooden floors, and walls from drying out and developing cracks or erosions.

Benefits of Diffusers

  • Uplifts mood: Diffusers are a great way to breathe life into a dull atmosphere as it infuses the air with a strong aroma of essential oils, making the room livelier.
  • Mental well-being: The essential oils poured in diffusers have a great soothing and calming effect on one’s mind and body, especially while performing yoga or meditation. Having a soothing aroma in the air can also aid in maintaining focus and clarity of thoughts when you are doing important work.
  • Help treat skin problems: With seasonal changes, skin problems are likely to take a toll on our health. With the use of an effective diffuser, the scent around the house will help you cope with skin irritation, inflammation, and other similar medical conditions. 
essential oil into diffuser
  • Useful during hormonal changes: The device is a boon for people with hormonal imbalance, especially for women during their menstrual cycle or pregnancy. It can help you feel more balanced during these periods.
  • Soothe severe pains: The medicinal benefits of essential oils can help reduce muscle soreness, joint pains, or strains.

Can Humidifiers and Diffusers Substitute Each Other?

Humidifiers and diffusers are different in how they function. Humidifiers are built primarily to humidify the air, whereas diffusers are designed to inject essential oils into the air. 

However, people often confuse the two devices as they are similar, and may even try to use them interchangeably without care for the results. 

While both devices sound similar and may appear to be doing similar jobs, humidifiers and diffusers should ideally never be considered as substitutes for each other.

Why Can Humidifiers Not Replace Diffusers?

  • Suppose you use essential oil in the humidifier. In that case, it is likely to harm the humidifier plastic tank as the oil tends to be warm and can break and make your humidifier stop functioning altogether. 
  • When a few drops of essential oils are poured into a humidifier, the nebulizer inside the humidifier tends to break down as the oil can clog the mechanisms inside the machine.

What’s the Alternative?

Humidifiers do not go well with concentrated oils as these are very thick and can cause a problem with the components. However, it is worth noting that there are two different types of humidifiers available for essential oils: an Airwasher and a 2-in-1 Humidifier & Diffuser.

Read more: Can You Put Essential Oils in a Humidifier?

Can You Use an Oil Diffuser as a Humidifier?

Yes, you can use an oil diffuser as a humidifier because it will increase the humidity in your room, but I would not recommend it. Because:

  • Diffusers are typically very small in size as compared to humidifiers. As a result, the water tank of a diffuser tends not to last long enough to properly humidify a room, so you may need to fill the diffuser tank repeatedly.
  • Diffusers work slower as compared to a humidifier. So, if you expect a diffuser to humidify the air in 2-3 hours, this is not likely to happen. 
  • Since the diffusers take in less water, the mist created by diffusers is not going to be super strong. 

In a nutshell, diffusers can be used as a humidifier when the moisture level in a room is not excessively low. If you need strong humidification, they might not be a great substitute for humidifiers as they simply do not humidify as effectively.

What’s The Alternative?

Ideally, you should have between 30-50% humidity in the room. If you want to use your diffuser as a humidifier, it is important to understand how much moisture is needed in the room. If you want a moisture level close to 40% and are patient enough to refill the diffuser tank several times, then diffusers can do the trick. 

However, it is important to note that only a humidifier can do the job if the room needs to be heated along with being moisturized.


Types of Humidifiers

Choosing the right humidifier is easy if you can address three simple issues: Price, requirement, and area. 

There is a fine line between choosing a good humidifier and a bad one, and it’s often confusing because so many options are available in the market. We have prepared this small guide to help you understand the differences.

There are five main types of humidifiers available in the market:

Cool mist humidifier

If you are hunting for a humidifier that is as effective in summers as they are in winters, then this type of humidifier can work well all year round. Place it in a large hall or large-sized room; a cool-mist humidifier works perfectly in large areas.

The humidifier operates by passing water through a filter to get rid of dirt particles and then puffing it out in the form of a cool-mist (hence the name).



✅ Safe for kids and pets

✅ Best for warm climates


❌Low noise

❌Requires maintenance

Warm Mist Humidifier

While cool mist humidifiers are more suited to warmer climates, warm mist humidifiers function better in colder climates. In this device, the water is superheated to kill the bacteria and other dirt particles (instead of passing it through a filter). 

Once it cools down to a warm temperature, the water is expelled through a fan, creating a warm mist and adding moisture to the room. 


✅Best humidifier for purifying air

✅Helps to clear away dirt and bacteria build-up within a room

✅Allows for sound sleep as they are very quiet


❌Potentially unsafe for kids due to warm moist air

❌More expensive and needs frequent cleaning

Ultrasonic Humidifier

With ultrasonic humidifiers, the metal plates inside the device cause vibrations at a high frequency. These vibrations break the water into tiny particles, which then disperses out in the form of a spray. 

These humidifiers are often designed with automatic functions, which makes them the most efficient amongst the various types of humidifiers. 


✅Available in warm and cool mist options

✅Self-automated features

✅Ultra-low noise

✅Consumes less electricity


❌Tends to be more expensive

❌Few models do not have a filtration system

Evaporative Humidifier

This type of humidifier passes water through a wick filter that is then converted to water vapor through an internal fan and then diffused out in the environment. Evaporative humidifiers work best if you have cold and flu symptoms. 


✅Automatic controls

✅Easy to carry and clean

✅Child and pet friendly

✅Quick results


❌Tends to make more noise

Steam Vaporizer

Steam vaporizers are the rare combination that offers the features of warm and mist humidifiers together. With multi-feature benefits, the steam vaporizer warms the water, creating steam that fumes out in the air. Additionally, the vaporizer can be set to cool settings, during which it can release cool mist. With their multi-temperature functionality, steam vaporizers can be used 12 months in a row.


✅Fits well to any season


✅Serves dual-function effectively

✅Quiet in nature


❌Harder to clean

❌Consumes more power

Related article: Best Humidifiers for 1000 Square Feet

Types of Diffusers

Diffusers also come in various shapes and sizes. Perhaps, the small size might fool you into thinking that they are not really very efficient. However, do remember that their main function is not that of a larger humidifier, but rather to diffuse essential oils into the air. 

We have prepared below a list of diffuser types to help you understand which type is suitable for your purpose. There are four main types of diffusers.

Nebulizer Diffuser

When you pour down an essential oil into the nebulizer, the oil moves upwards through a narrow stream at a high rate to create powerful fumes in the air. Fairly efficient in size and performance, nebulizers have a calming effect on one’s mind and physical health. 


✅Compatible with any essential oil

✅Does not require heat or water

✅Creates a high pressure for a long-lasting effect



❌Utilizes more oil

❌Can be noisy

Ultrasonic Diffuser

Similar to ultrasonic humidifiers, ultrasonic diffusers use rotating discs to break down oil in tiny droplets of mist. These types of diffusers mix water in addition to essential oil to create a fine mist at high frequency. 


✅More efficient use of oils, so less is required

✅Maximum output


❌Slows down the system

Heat Diffuser

These types of diffusers use heat to transpose a strong fragrance of essential oils. These also use oil and water mixture along with heat to infuse the air in appropriate proportion. 




✅Strong aroma


❌Releases hot mist, so may not be suitable for children

❌The heat changes the natural oil essence

Evaporative Diffuser

As the name suggests, evaporative diffusers work through an air-based medium to lift up the oil. When you pour an essential oil into the system, the oil transposes through airflow to a filter, which can be either a tissue or a pad. 

Air is forced into this pad to push the oil to blow out in sections across the room. The lighter oils move out easily, whereas the heavier oil components follow later.


✅Wind-blown method

✅Delivers quick results


❌Not as effective as other diffusers

Final Thoughts

Now that you are familiar with the differences between humidifiers and diffusers, you are equipped with the knowledge to select one for yourself.

As a final word of caution, we again suggest you not to try substituting the devices as either will work effectively only for its primary purpose. Trying to use one for the other’s purpose and expecting good results will likely disappoint you.

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