What Does an Essential Oil Diffuser Do?

Air fresheners and scented candles might seem like quick fix solutions to rid our homes or offices of any unpleasant odors, or simply to keep the place smelling nice – but they are not without their problems. Candles always pose the risk of a fire if you have unruly kids or pets running around, and as effective as they might be in releasing enzymes which cancel out bad smells, they can still be quite polluting if they’ve got some paraffin in the mix. Air fresheners, on the other hand, merely mask smells, rather than get rid of them completely, and apart from their ephemerality, also come with phthalates, chemicals which have been linked to multiple health concerns.

This is where essential oils come in. While they may be considered slightly more expensive alternatives – depending on the type of essential oil you choose – they are an all-natural means of leaving your home or workplace fragrant, with the help of the right diffuser.

Essential oils & aromatherapy

Why diffuse essential oils?

Extracted from plant matter – from seeds to leaves to flowers – these all-natural oils offer a concentrated punch of nature no matter what they are used for, be it skincare and cosmetics, or aromatherapy. While there has been no concrete clinical conclusion that essential oils can be directly linked to health benefits, studies and individuals subscribing to this type of alternative medicine have identified the healing abilities of inhaling essential oils. Associated with reducing stress, aiding sleep, alleviating tiredness, improving one’s mood and even helping cope with depression, these oils can be absorbed directly from the air when diffused, delivered straight to where they are needed.

Diffusing essential oils

So what type of diffusers should we be looking at? It depends, in part, on your preferences. The most popular types of essential oil diffusers are generally ultrasonic diffusers and nebulizers – electronic, heatless diffusers which don’t alter the oils’ composition. Here is a breakdown of how they work.

Ultrasonic Diffusers

These are the cheaper of the two, and are water-based. The best options will come with a largish water tank, clearly marked with the maximum capacity you can fill them to – the more water the tank can hold, the longer you can keep your diffuser running without needing to refill it. A few drops of your chosen essential oil into this, and this cold diffusion device works the water and oil into a fine mist by using high-frequency sound waves bubbling through the liquid. Since heat is not used, the structure and composition of the oils are not altered and therefore retain their properties and benefits – though the addition of water means the mist is a very diluted version of the oil, and more effective at wafting a subtle scent through the room it is placed in than anything more heavy-duty. If you want a stronger scent, you’ll have to add more oil.

Ultrasonic diffusers often come in translucent plastic casings which light up when activated – at home, this might entertain the kids or your pets, or even add a nice ambiance depending on the style and type of lighting, but may not appeal to everyone, especially if you are thinking of adding one to your workplace. The ideal option lights up discreetly, without being too glaring or garish.

We also recommend looking into a diffuser with a timer – this lets you control how long your diffuser will be running, so you avoid overusing it and get the most out of the mixture without having to frequently refill. Smaller diffusers do require more frequent refilling, but are often programmed to spray out a concentrated burst of mist at given intervals, so they leave a lingering aroma for some time before the fragrance needs to be restored again.

Because of the water-based aspect of this device, some ultrasonic diffusers are also advertised as humidifiers, for adding that extra degree of moisture into the air. Nonetheless, the humidifying abilities of most diffusers, especially those on the smaller scale, are negligible, so be wary if you are specifically looking for a device which can help add a little moisture to your home during dry, winter months.


If you are looking to scent up a bigger space, or to enjoy a stronger, more concentrated scent likely to have more tangible therapeutic effects, these are the heavy-duty diffusers you need. A nebulizer is also a cold diffusion device, heatlessly working pure essential oil, without dilution, into a fine mist by running high pressure, compressed air through it. As a result, you get stronger fragrance, enough to scent up a whole flat or home.

Because of this, a nebulizer is the better choice if you are actually looking to engage in aromatherapy – since the process doesn’t alter the chemical structure of the oil itself, the health benefits and properties remain the same, easy to absorb by simply inhaling in the mist. Since these don’t pump additional moisture into the air, they’re also effective if you intend to use them where it tends to get humid – but will run out faster, since they are spraying out pure oil.

Because of the high air pressure required to convert oil to mist, nebulizers tend to be noisier as well as more expensive, though the best brands offer diffusers which let you control the intensity of the diffusion process – the lower the intensity the quieter the noise, as well as the longer you get to use the nebulizer without needing to refill.

Nebulizers might also be a little finicky to clean – many come with glass jars or components, meaning they need to be handled with care, especially when washing down the oil which may have accumulated inside, and kept well out of reach of children. With their glass and oftentimes wood-based designs, though, nebulizers are generally more aesthetically pleasing and sturdy than ultrasonic diffusers.

Opportunity Cost

Essential Oils

While nebulizers definitely win when it comes to stronger scents and aesthetic appeal, they also run through more essential oils than we may be willing to use up, especially if they tend to lean on the pricey side. If you’re looking to scent up a single room or a small flat, a diffuser with a medium to large tank can be discreetly tucked into a corner to infuse a subtler scent around your home, while nebulizers are the better deal for stronger fragrances and large, more open spaces.