Nadine Walder , 22 February 2023

Humidify the air

The difference between humidifiers and aroma diffusers: what you need to know

Humidifiers and aroma diffusers both use water and are often confused with each other as a result. While the former humidify whole rooms, the latter fill the room with fragrance in the form of mist. Because aroma diffusers emit a small quantity of water, we are often asked whether these devices can also be used as humidifiers. The answer is simple: no. Humidifiers and aroma diffusers differ in several respects. Read this article to find out everything you need to know about the differences between these devices and when each of them should be used.


Visual differences between humidifiers and aroma diffusers

You can tell the difference between humidifiers and aroma diffusers pretty quickly just by looking at them. Aroma diffusers tend to be small decorative devices so they come in different shapes and colours and fit in well as decorative elements in lounges and offices. Humidifiers, on the other hand, tend to be bigger because they have to be able to emit a larger quantity of water into the room.

Unlike humidifiers, some aroma diffusers have additional light functions for improving the atmosphere in a room. These can take the form of LED lighting in different colours or mood lighting to create a relaxing atmosphere in a room. Stadler Form also offers aroma diffusers with a special flame effect. 

A final point worth mentioning in terms of appearance is the size of the water tank. Humidifiers usually have larger water tanks so that they can store more water. In the case of humidifiers, the technical data should always indicate the humidification capacity (how much water is emitted into the indoor air per hour) and the water quantity. The latter will determine the running time. Aroma diffusers have a smaller capacity and small water tanks because they are designed for the nebulisation of essential oils. It is not possible for aroma diffusers to have a high capacity on account of their technology and size.

The difference between humidifiers and diffusers: Range of applications

Humidifiers and aroma diffusers are used in different environments. Humidifiers are used in dry rooms in which the level of humidity is low. That is often the case in rooms with air-conditioning or during the winter months when the heating dries out the air. A humidifier increases the level of humidity and can help reduce itchy eyes, dry skin, dry mucous membranes and a scratchy throat.

Aroma diffusers, on the other hand, are suitable for people who want their room to smell good and want to enjoy the benefits of essential oils. An aroma diffuser can be used in any room you want to fill with fragrance. The use of essential oils with an aroma diffuser can help improve your mood, relieve stress and create a relaxing atmosphere in a room.

How does a humidifier work and how does an aroma diffuser work?

Humidifiers and aroma diffusers have different functions: humidifiers increase the level of humidity in order to improve well-being and health while aroma diffusers diffuse essential oils in order to improve well-being and mood.

The two devices work in different ways. In the case of humidifiers, we generally distinguish between four different systems. Vaporisers heat the water in the device and the hot water vapour is emitted into the indoor air. In the case of ultrasonic nebulisers, ultrasonic technology is used to split water into tiny droplets which are emitted into the room in the form of mist. An evaporator sucks in the dry indoor air, guides it through the water-saturated filters inside the device and emits it back into the room, optimally humidified. Finally, an air washer also works in accordance with the principle of evaporation and is a combination of humidifier and air purifier. 

Aroma diffusers also work in different ways. Stadler Form aroma diffusers either use ultrasonic nebulisation or evaporation for room fragrancing. Ultrasonic aroma diffusers use a membrane to split water and essential oil into tiny droplets which are emitted into the room. In the case of aroma diffusers based on evaporation, we use fragrance globes for room fragrancing. With these, either a fan blows air across the fragrance globes to release the fragrance or the indoor air flows through the balls and absorbs the fragrance directly.

Humidifiers with an aroma function

The decision on whether you should use a humidifier or an aroma diffuser will depend on your requirements and the type of room. Humidifiers are particularly useful in rooms where the air is dry while an aroma diffuser can be used in any room to fill it with a pleasant fragrance and create a relaxing atmosphere.

If you want both ideal humidity indoors and a pleasant fragrance, there are solutions to meet these needs too. You can add essential oils to some humidifiers. Our Ben, for example, is a 3-in-1 device. He humidifies the air, fills the room with a pleasant fragrance and has a cosy open fire effect. Our humidifier families Oskar and Eva as well as air washers Robert and George have a fragrance container to which you can add drops of your chosen essential oil. 

If you are still not sure whether an aroma diffuser, a humidifier or a combination of both is right for you, we will be happy to give you advice on which to choose.


If you have questions related to indoor room climate, please get in touch with us. Or subscribe to our newsletter to regularly get informed about current topics regarding indoor climate, experience reports or Stadler Form insights.