Humidifier Vs Diffuser – Which Is Better For Your Needs?

Ile Kauppila

Written By

Ile Kauppila

Expert Reviewed By

Josh Mitchell

Last Updated On

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Due to my breathing issues, I use a humidifier and a diffuser in my home.

One improves my home’s air quality by adding moisture to it and the other uses essential oils to add a fresh fragrance to the air.

Which unit does which job, though? I have been asked countless times about which option is better and why.

So, in this guide, I’ll explain what the difference between a humidifier and a diffuser is and when you should use each device.

Key Takeaways

  • Humidifiers improve air quality in dry environments by adding moisture to the air.
  • Diffusers disperse essential oil scents into your living space.
  • Both are beneficial to your health – humidifiers combat dryness-related illnesses, whereas, diffusers promote aromatherapy.

Humidifiers Vs Diffusers: Key Differences Explained

humidifier vs diffusers

Although they seem similar, humidifiers and diffusers differ in many ways. Here’s my breakdown of the most significant differences between them.

Diffusers Cover A Much Smaller Area

Diffusers are generally smaller and can’t cover very large areas.

I use a very small unit, for example — just big enough for my bedroom.

Humidifiers come in a wide variety of sizes, from small personal units to huge whole-house humidifiers, and can humidify even large rooms and buildings.

That said, there’s a range of sizes available for both machines.

Pay attention to a diffuser’s or humidifier’s volume to match it to the size of your living space and get the most benefits.

humidifier sqft coverage

TL;DR: Determining the volume of the room is the first in determining what size of humidifier or diffuser you need.

Humidifiers Improve Air Quality, Diffusers Don’t

Essential oil diffusers do not generally improve air quality — they only add scents and fragrances into the air.

Although some essential oils, like eucalyptus, have antibacterial properties, diffusers aren’t designed to enhance air quality.

Humidifiers, on the other hand, can improve the quality of indoor air but adding moisture to it.

What are the Optimal Humidity Levels

A humidity level between 30-50% can moisturize your airways, destroy airborne viruses, and reduce asthma and allergy symptoms.

I can breathe much easier with properly humidified air.

TL;DR: If you face health issues caused by dry air, then you need to procure a humidifier.

Diffusers Have A High Scent Strength

I love my diffuser because it adds strong, lovely scents to my home. These machines are purpose-built to dispense fragrant essential oils into the air.

Basic humidifiers don’t produce scents because their goal is to build up the moisture level in dry air.

Important Note:

Any scents (good or bad) coming from your humidifier could be a sign of operational problems.

Both Offer Different Health Benefits

Both essential oil diffusers and humidifiers can provide health benefits — only in different ways.

A humidifier can bring you significant health benefits, including:

  • Reducing coughing and congestion
  • Providing relief for asthma and sinus problems
  • Keeping your skin and hair moisturized
  • Destroying airborne viral particles (1)
  • Relieving snoring (my wife really appreciates this benefit)

Meanwhile, you’re likely to see these diffuser benefits:

  • Aiding relaxation and feelings of calmness
  • Reducing anxiety
  • Promoting peaceful sleep
  • Improving mood
  • Reducing congestion and inflammation
  • Providing relief for skin conditions

TL;DR: While humidifiers physically help you with many ailments, diffusers provide benefit to your mood and mental state.

Diffusers Can Affect Your Mood

Diffusers win when it comes to influencing your mood. The essential oils used with a diffuser create a spa-like aromatic environment in your home.

My unit can really improve your mood, depending on the essential oil I use.

A humidifier only emits a fine mist or water vapor into dry air to increase moisture levels.

They don’t do anything in particular to improve your mood. That said, being able to breathe easier does make me a lot happier!

Available In Varying Sizes But Humidifiers Are Larger

Diffusers and humidifiers are both available in many sizes for use in different rooms.

Humidifiers tend to be larger, though, since boosting the humidity in your home is a more intensive process than wafting scents around.

Let me illustrate this.

A diffuser’s water reservoir holds on average around 1-2 cups of water.

An average humidifier tank, on the other hand, has a volume of around one gallon.

TL;DR: Humidifiers are often larger is size and can hold more water as compared to diffusers.

Diffusers Are Cheaper Comparatively

When it comes to humidifier vs. diffuser price, diffusers tend to cost less than humidifiers.

They are generally smaller and simpler devices, which keeps their price low.

The retail price depends entirely on the unit’s size, volume, and additional features, though.

I’ve seen a high-end luxury essential oil diffuser with all possible bells and whistles costing triple or more than what a basic desktop cool mist humidifier does.

Humidifiers Have A Higher Running Cost

Humidifiers and diffusers both need electricity to run, which will add to your monthly utility bills.

However, humidifiers consume more energy on average than diffusers.

Humidifiers tend to be larger and require regular filter changes, which adds to their running costs.

If you want to minimize your device’s running costs, look for Energy Star or other energy efficiency labels on the box — or my favorite, ultrasonic humidifiers.

TL;DR: Humidifiers not only consume more electricity, some types also require regular filter change adding to the overall operation cost.

Humidifiers Are High Maintenance Compared To Diffusers

Humidifiers need more maintenance than diffusers. That said, you should clean both units regularly — I recommend doing it once a day — to prevent mold and bacterial growth in the water tank.

The cleaning process is similar between both devices.

Humidifiers may require you to replace filters too or other consumable parts to maintain their effectiveness. It’s not a huge task, but still, more than you need to do with most diffusers.

Their Respective Hazards Are Different

Both kinds of devices have water tanks that could leak or spill, causing water damage.

If you don’t clean the tanks regularly, they could also get moldy and introduce spores or bacteria to the air in your home.

Humidifiers can increase the humidity level in your home too much.

Excessive moisture in the air can promote the growth of mold, bacteria, and dust mites that could cause respiratory issues.

I accidentally got my curtains moldy with my first humidifier.

On the other hand, if your diffuser is too powerful for a small room, the overwhelming scent could cause headaches or breathing issues.

Additionally, you must be careful not to use essential oils that could bother allergy sufferers. (2)

Also, do not put essential oils in an average humidifier.

Can you put essential oils in humidifier

TL;DR: Both carry certain risks. The key is to not go overboard with humidification or with oil diffusion.

What Do Humidifiers & Diffusers Have In Common?

Despite their differences, there are things that humidifiers and diffusers share with each other. I’ll detail the similarities between them below.

Both Can Add Moisture

Both a humidifier and a diffuser can add moisture to indoor air since they use water vapor.

However, humidifiers are designed specifically to boost moisture levels and will be far more efficient.

Diffusers add moisture only if the diffuser is an ultrasonic/humidifying diffuser.

Both Have Disinfecting Properties

Humidifiers help control allergens

Humidifiers can reduce the levels of viral particles because higher humidity levels make it difficult for viruses to survive.

Disinfecting essential oils, such as eucalyptus, lavender, geranium, lemon, clove, or thyme, can also destroy certain viruses when dispensed through a diffuser. (3)

That said, neither device is intended to clean indoor air. I recommend looking into air purifiers to clean your home air.

Easy-To-Use Design Is Typical For Both Devices

Most modern diffusers and humidifiers have easy-to-use designs that make operating them a breeze.

Between auto shut-off functions, mist speed and volume controls, timer options, and accessible water or essential oil refill valves, it is easy to add one of these devices to your home.

They Have A Similar Lifespan

Most humidifiers and diffusers can last anywhere from 5 to 15 years.

Your device’s lifespan will depend greatly on its brand, build quality, and how well you maintain it.

With proper cleaning and maintenance, you can enjoy the benefits of a high-quality diffuser or humidifier for years to come.

I recommend investing in a good unit because the cheapest available device can break within months or weeks.

TL;DR: While both are different devices, they do have some minor overlaps. Still, the devices should not be used interchangeably.

What Does An Oil Diffuser Do?

Oil diffusers work to create a spa-like home environment with calming fragrances that can make it easier to breathe.

Different types of diffusers emit essential oils in different ways.

Nebulizing Diffusers Use Pressurized Air

A nebulizing diffuser forces a pressurized air stream through tubes containing essential oil, turning it into an oil mist that spreads into the room.

They create a cool mist because they do not use heat or water, so they are easy for busy homeowners.

Ultrasonic Or Humidifying Diffusers

Ultrasonic diffusers send out a water-based oil mist. The diffuser has a vibrating plate that breaks the oil-laden water into a fine mist.

These machines can boost air moisture levels in small amounts.

Evaporative Diffusers Use Fan

An evaporative diffuser uses a fan to evaporate essential oils into the air in gas form.

This works well for people who are only interested in the scent of the essential oil (like me).

Heat Or Electric Diffusers

A heat diffuser uses a heat source to warm and evaporate essential oils.

This kind of silent unit is less common. These devices can get too hot to be in rooms with children, so there are some safety concerns to be aware of.

TL;DR: The principle of operation for diffusers is almost similar to humidifiers. However, diffusers are far more efficient and use parts and components that would not break due to the corrosive nature of the oils.

Pros & Cons Of Diffusers

  • Fragrant aromatic scent
  • Fun light features on some devices
  • Calming Zen presence created with essential oils
  • Essential oils can have health and aromatherapy benefits
  • Low maintenance
  • Do not add moisture to dry air
  • Will not help with congestion in sinuses
  • Small area coverage

What Does A Humidifier Do?

A humidifier adds moisture to dry air and increases the overall humidity level in the room.

These devices are generally split into warm mist and cool mist humidifiers.

Types of humidifiers

Warm mist humidifiers boil water with a heating element to produce steam vapor.

They can be very effective at humidifying a room but come with similar safety concerns as heat diffusers.

The most popular types of humidifiers are cool mist humidifiers, such as ultrasonic humidifiers and evaporative humidifiers.

Ultrasonic humidifiers are my favorites and work like ultrasonic diffusers — using a vibrating diaphragm to create water droplets.

Important Note:

Despite evaporative humidifiers having a filter, they are not intended to clean the air.

Evaporative humidifiers have a fan that blows air over a wet wicking filter to introduce moisture to the space.

TL;DR: A humidifier serves the primary purpose of increasing the humidity levels. There are different types of humidifiers ultrasonic and evaporative humidifiers being the most popular choices.

Pros & Cons Of Humidifiers

  • Comfortable humidity levels
  • Helps with sinus congestion
  • Helps with allergies
  • Better sleep and less snoring
  • Helps reduce virus levels
  • Healthier plants and wood furniture
  • No fragrance
  • White dust from hard water
  • Requires daily cleaning

Are There Humidifiers That Are Also Diffusers?

Yes, there are aromatherapy humidifier/diffuser combinations that provide both a sweet, perfumed scent and add moisture to the air.

These combinations are often called aromatic ultrasonic humidifiers.

This kind of cool mist humidifier dispenses both water and essential oils in the mist it creates.

The water slowly brings up the humidity level, and the oil adds a delightful scent to the space.

Personally, I’m not a huge fan of these units as they need to be run for a longer time to have a noticeable effect.

Some humidifiers have containers for essential oils. As the humidifier runs, it also introduces oil into the air.

TL;DR: There are some special humidifiers that can also work as diffusers such as the aromatic ultrasonic humidifiers. They are not as efficient as dedicated diffusers, but they are compatible with all kinds of essential oils.

People Also Ask (FAQs)

Can You Use A Diffuser As A Humidifier For Plants?

No, you cannot use a diffuser as a humidifier for plants. Diffusers don’t increase air moisture enough to benefit plants.

Can You Run A Humidifier And Diffuser At The Same Time?

Yes, you can run a humidifier and diffuser at the same time. I recommend keeping them at least two feet apart so that they don’t interfere with each other.

Can You Sleep With A Diffuser On?

Yes, you can sleep with a diffuser on. However, I recommend purchasing a unit with an automatic shut-off setting in case the device runs out of oil.

Do Oil Diffusers Help You Sleep?

An essential oil diffuser can help you sleep. Some people sleep better when they breathe in calming fragrances, such as lavender or eucalyptus, but others are not affected by the scents.

So, Which Is The Better Option For You?

Humidifiers and diffusers both help you breathe easy in your home. With my guide, you now know which unit is right for you.

If you want more moisture in your home air, choose a humidifier. But if it’s a calming fragrance you’re after, purchase an essential oil diffuser.

Or, you can do what I did and buy both! Using a humidifier and diffuser together can create an optimal home spa experience.


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Ile Kauppila

MA Multimedia Journalism / BA English Philology

Ile Kauppila
Ile Kauppila is a globetrotting writer and editor living in Virginia. Ile holds an MA degree in Multimedia Journalism and a BA in English Philology. Ile has written for a variety of home, HVAC, and energy-related websites and publications. He has covered HVAC solutions, insulation, and energy-efficient construction, automotive AC systems for multiple auto dealerships and garages.

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