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Diffuser vs Humidifier vs Vaporizer: Which Is Best?

The ultimate battle between diffusers, humidifiers and vaporizers.

If you’re looking to increase the humidity in your home, you’ve likely come across three very similar devices.

Humidifiers, vaporizers, and diffusers might seem alike, but they differ in purpose. To answer all your questions, we’ve spent hours searching everything you need to know about these three devices.

Which type would suit you, and how do you choose the right one for you? Let’s walk through what they all do, how they work, and finally, who the winner is.

Key Takeaways

  • Diffusers disperse essential oils and increase humidity, while humidifiers and vaporizers primarily increase humidity in your home.
  • Cleaning is crucial for all devices to prevent buildup and maintain efficiency; use vinegar for cleaning diffusers, humidifiers, and vaporizers.
  • Diffusers generally cost between $15 and $50, humidifiers range from $25 to $150, and vaporizers typically cost around $20 to $35.
  • For allergies and congestion, vaporizers are the best option due to their ability to release clean, sterilized moisture into the air.

What Do They Do?


A diffuser is a device that disperses essential oils through the air. It works similarly to a humidifier by emitting moisture into the air. However, you can add your favorite essential oil to the tank or an oil tray.

As you turn on the device, the essential oils are mixed with the water and emitted into the air. Diffusers are often used to create an aromatic atmosphere and can offer many health benefits by increasing humidity.


A humidifier’s sole purpose is to increase the humidity in your home. There are different types of humidifiers ranging in size and function. Humidifiers are meant to keep the relative humidity in your home at a comfortable level between 30 and 50 percent.

You simply fill the tank with water and select your desired setting. Most devices feature a timer that you can set to suit the hours you’d like the device to work.


Vaporizers increase the humidity in your home, similar to humidifiers. But, they work differently.

Vaporizers use electrically powered heating elements to heat the water in the tank. As a result, the water boils and creates steam which is then dispersed through the air.

How They Add Moisture to the Air


A diffuser mixes water from the reservoir with the added essential oil, which is then dispersed in the air. Essential oil diffusers can help to bring some much-needed humidity to a room, but they aren’t as effective as humidifiers.

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A common type of humidifier is ultrasonic. This humidifier uses ultrasonic vibrations to emit a strong mist of moisture into the air. A cool mist is dispersed in tiny, easily inhaled particles. Plus, because it’s cool, it won’t cause dampness.


Vaporizers, on the other hand, utilize heat to create steam or vapor that you can inhale. Although it’s often called a warm-mist humidifier, the moisture which is dispersed is cooled before it reaches you.

However, keep children and pets away from the unit because the water can be hot when it first disperses.

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How They’re Cleaned


It’s essential to clean your essential oil diffuser regularly since the oil can build up and cause clogs.

One simple way to clean the diffuser is by filling the tank with clean water and adding two squirts of dishwashing soap. Allow the mixture to sit for a minute or two, then use a sponge to scrub the inside gently.

Additionally, you can also add two teaspoons of white vinegar to the clean water and leave it to sit for up to 10 minutes.

Keep In Mind

Always unplug the diffuser, humidifier, or vaporizer before cleaning it to avoid any risk of electrocution.


A common problem with humidifiers is a build-up of limescale or minerals within the tank and disperser. This often occurs if you’re using tap water that’s high in minerals — also known as hard water.

Another issue is mold or mildew, which can occur if you leave water in the tank for an extended period.

The easiest way to clean a humidifier is by taking it apart and adding a couple of teaspoons of white vinegar to the tank. Fill it halfway with water, and then give it a good shake. The vinegar will effectively remove mold, mildew, limescale, or mineral build-up.


Because vaporizers heat the water, it’s crucial to unplug it and leave it to cool for 30 to 60 minutes before cleaning. Next, you should empty the tank if there’s any water left and remove the heating element. Fill the tank with clean water to rinse, empty the contents, and wipe it.

To clean the heating element, soak it in pure white vinegar for up to 10 minutes, then rinse it under the tap. Make sure you cover the steam outlet with your finger. In between rinsing, turn it upside down to empty any water inside the element.

How Much They Cost


Depending on size and design, diffusers typically range in prices between $15 and $50. Some devices can be higher priced because you also get a few essential oil samples to try.


Humidifier prices range between $25 to $150. The more expensive models come with larger tanks and various features, whereas the cheaper models are smaller and simpler.


Vaporizers typically cost a little over $35, but you can easily find models that cost around $20.

How Safe They Are


Diffusers are considerably safe, but there are a few things to remember, especially if you have children or pets.

Some diffusers can become quite hot as they heat the water and oils. This can be dangerous if within reach of young children.

Another danger could be oils. Cats and dogs can be especially sensitive to specific essential oils due to their high concentration (1).

Safety First

If you have pets or children, keep the diffuser out of their reach and preferably in a separate room.


Cool-mist humidifiers are safe to use around pets and children. They do not create heat or disperse potentially harmful essential oils. However, you may still want to keep them out of children’s reach to avoid the device being knocked over.

Keep in mind, however, that if you don’t maintain your humidifier properly, it could potentially emit contaminants and mold into the air.


The main concern with vaporizers is burns. If the device were to fall over, boiling water would be spilled, which would burn your skin. If you have children or pets in the house, keep the vaporizer far out of reach to ensure it won’t burn them.

How Well They Work for Allergies


Specific essential oils can have beneficial effects when it comes to allergies. For instance, peppermint reduces inflammation.

However, adding the wrong oils or combinations could cause an allergic reaction. So it’s essential to do some research before adding oils.


Low humidity levels can irritate the airways, but high humidity is the main cause of indoor allergens.

High humidity levels can cause dust mites as well as mold and dampness (2). Keeping the humidifier clean is also crucial to avoid mold being dispersed through the air.


A vaporizer is a better option for dealing with indoor allergies and low humidity. Because the water is boiled, contaminants are killed and removed, resulting in a clean mist.

How Well They Work for Congestion


Similar to allergies, the diffuser’s effectiveness depends solely on the oils you’re using. Peppermint and eucalyptus oils are well-known for easing congestion and opening the airways (3).


A humidifier is very effective at easing congestion. It’s a popular device to help you deal with cold and flu symptoms as well.


Similar to humidifiers, vaporizers add a good amount of moisture to the air that will help to ease congestion.

Can You Put Anything Inside Them?


You can add your desired essential oils to the tank.


Never add essential oils to the tank of a humidifier since the oils can damage the internal parts. If you want to add some scents to your humidifier, you can add water-soluble scented additives. But always check with the manufacturer first.


Certain brands of vaporizers, such as Vicks, allow you to add inhalants such as Vicks’ Soothing Vapors. However, this shouldn’t be used around young children.


When Should You Not Use a Humidifier?

You should not use a humidifier when the moisture levels are already high. Also, don’t use a dirty humidifier because that will spread germs and potentially encourage mold growth.

Which is Better: Cool Mist or Warm Mist Humidifier?

Deciding which is better between a cool mist and warm mist humidifier depends on personal choice. However, warm mist humidifiers are quieter because they don’t rely on a fan to disperse the mist, and are better for dispensing medicinal additives that help with seasonal ailments.

They also humidify the air more efficiently and reduce bacteria and germs.

Do Diffusers Cause Mold?

Diffusers can cause mold because mold spores can multiply in the dark and damp water reservoir. It’s always advisable to change the water regularly because stagnant water breeds germs and bacteria.

Is It OK to Sleep With a Diffuser On?

It is okay to sleep with a diffuser on, provided it doesn’t wet the air too much. Choose a diffuser with a timer to control when it turns off and on.

Where is the Best Place to Put a Diffuser?

The best place to put a diffuser is three feet away from where you sit or sleep, away from direct sunlight, and elevate two feet from the floor. Also, don’t place it next to furniture because excess moisture will cause damage and mold growth.

How Long Can You Keep a Vaporizer On?

You can keep a vaporizer on for five to fifteen minutes, depending on the room conditions, capacity of the water reservoir, and other factors like the setting. Selecting the lowest mode extends the runtime of the vaporizer.

And the Winner Is…

Adding a bit of moisture to the air is excellent if you’re dealing with dry skin or congestion issues. Diffusers, humidifiers, and vaporizers all work effectively at adding moisture to the air. So how do you choose?

A diffuser is the clear winner if you want a pleasant scent and the benefits of essential oils. But it’s not going to increase humidity levels massively.

A humidifier is a must-have if you need to increase humidity levels in your home quickly and effectively.

A vaporizer is a fantastic option if you want something to increase humidity levels while being a bit more hygenic. The steam will ensure the water is clean and sterile.

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About the Author

Matthew Sullivan

Matthew Sullivan is a technical writer with over 15 years of hands-on experience in the realm of HVAC, humidity, air purification, and mold prevention. With a background rooted in mechanical engineering, Matthew seamlessly blends the intricate world of technicalities with the everyday challenges that homeowners and businesses face. His vast expertise has led him to collaborate with leading HVAC manufacturers, consult on cutting-edge air purification systems, and become a sought-after voice on mold mitigation.