A Guide to Nebulising Diffusers vs Ultrasonic Diffusers for the Home

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If you have ever Googled the word “diffusers”, you are already aware of how diverse the search results returned are. There countless methods to diffuse scents through your home, from little fans which plug into USB ports, to heated-warming plates, to reeds in glass jars, and this list carries on. 

Yet when it comes to diffusers there are 4 main types which include heat diffusers, evaporative diffusers, ultrasonic diffusers, and nebulizing diffusers. I won’t be talking about the heat or evaporative diffusers in this post, you can see more here, but I would like to mention that the heat diffusers will damage the oils that you are using, and that’s why I would not recommend using or buying one. 

A few weeks back I was sent an attractive and expensive nebulizing diffuser that I needed to do a review on. So I decided to spend the next two weeks testing and comparing the differences between the ultrasonic and nebulizing diffusers and to find out which one is a clear favorite. I decided to set up each machine in a different room, the ultrasonic in my kitchen, and the nebulizing machine in the living room. I spend about the same time in both of these rooms every day. 

Both of these diffusers create a very fine mist that diffuses the scents into the air. Yet this is where their similarities stop. 

What's Inside?

The Ultrasonic Diffuser

The ultrasonic diffuser uses ultrasonic vibrations which are caused by a disc that is small which is located inside the liquid. This disc breaks the essential oils up into micro-size particles which are then dispersed in a very fine mist through the air. These particles are absorbed very easily into the lungs. 

The Pros:

  • They add humidity into the room that you use them in
  • They are usually a more cost-effective choice
  • There are more designs and styles on offer

The Cons:

  • You shouldn’t or can’t use essential citrus oils inside them as the parts can erode
  • You have to fill the machine with water

Nebulizing/Nebulising Diffuser

The nebulizing or nebulising diffusers operate with a vacuum that pulls the essential oils or the liquids from the bottom part of a glass tube up to the top part of a micro-tube, while jets of air that come from a second micro-tube blows out micro-particles of the oils in the form of a very light vapor. The bigger particles will drop back down again inside the reservoir and the cycle repeats. This method allows larger volumes of the pure oil to disperse through the air rapidly. 

The Pros:

  • Easy setup and the system starts running immediately
  • You do not have to use water
  • These machines quickly release strong concentrations of the oil directly into the surrounding air
  • You are able to use the citrus essential oils in these machines 

The Cons:

  • They are slightly noisy 
  • It is not possible to use the resinous and thicker essential oils
  • They use up essential oils very quickly, so you will be spending a lot more money on your essential oils

What Is The Real Deal?

So after using both machines for a period of 2 weeks, here is my opinion on each machine. 

Physical Appearance and Design 

When it comes to appearance there are many attractive ultrasonic diffusers and nebulizing diffusers to choose from. They also come in different designs which makes it easy to find a style that matches up to your home or office space. There are a lot more options when it comes to the ultrasonic diffusers due to the way in which they operate which has allowed the manufacturers to produce a number of highly interesting designs. Overall, the nebulizing machines offer a more luxurious look and feel, due to the hand-crafted glass reservoirs. 

The Winner: For this round, it is a tie, as it is possible to get highly attractive designs for both the ultrasonic and nebulizing diffusers. 

Ease Of Use 

Before you can use an ultrasonic diffuser, there will be a place at the top that you have to open. Most machines feature 2 layers. The next step involves pouring water inside the well, making sure you avoid overfilling it, as this will flood your machine. Now add the oil, plug the machine in and press the on button. 

With a nebulizing diffuser, your first step involves removing the glass-cap. There is a reservoir where you can add your favorite essential oils. Now replace the cap and turn on the machine. 

Both machines will need to be cleaned every now and again, and it shouldn’t take you more than a few minutes. 

The Winner: For this round, the clear winner is definitely the nebulizing diffusers. It literally takes 5 seconds to get your machine running. 


The very first thing that I noticed when using the nebulizing diffuser for the first time was the very strong smell of the oils. Anyone that knows about essential oils is aware that for some oils when you first open the bottle you might not like the aroma of the oil, but you will end up loving the smell once you put it inside an ultrasonic diffuser. Oils diffused through a nebulizing diffuser will smell just like they do from the bottle, as the oils are not chemically altered throughout the process of diffusion. What this ultimately means is that if you do not like the smell of a particular essential oil, the oil will not change its aroma when you use it inside a nebulizing diffuser. 

Through my tests, I found that I could easily run the ultrasonic diffuser a lot longer. With the nebulizing diffuser, the smell can become overwhelming quite quickly, and in a short time the machine will use up the oils and then the smell disappears altogether. 

Instead of jumping to my own conclusions, I conducted a bit of research where I found out that the aromatherapists usually suggest only using nebulizing diffusers for a period of 15 minutes. I started to look at this machine as a type of therapeutic tool instead of a “very expensive air freshener”. After that, I started enjoying this machine a lot more. Overall, I prefer the more gentle and softer aromas that the ultrasonic diffuser produces, but when you need a specific essential oil for a therapeutic purpose, the nebulizer offers the best way to diffuse pure essential oils. 

The Winner: For this round, I personally prefer the ultrasonic diffuser which I could use for 4 hours at a time to diffuse a gentle and softer aroma.


It now makes sense why the professional aromatherapists use the nebulizing diffusers. They are also attractive in a more classical way, and similar to a type of alchemist’s tool, these machines easily deliver a full, pure, and clear diffusion of any essential oil along with potent aromas. Even though I did not test this for myself, I do understand that this type of diffuser is more appreciated for therapeutic applications when it comes to aromatherapy. 

Yet this is not to say you shouldn’t buy an ultrasonic diffuser. These machines offer outstanding value when it comes to more gentle and milder yet lengthy and consistent diffusion of different aromas using humidity. I also prefer the ultrasonic diffuser when it comes to my toddler as the smell is less intense and softer, making it a lot safer when it comes to what she is breathing in. 

My conclusion on these two machines is that there isn’t a clear winner. Both serve a different purpose. I am hoping that my thoughts on these two different diffusers will help you to make your own mind up about which one is best for your needs.

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