Essential oil diffuser purchasing advice: how to choose the right product

  • What You Need to Know
  • Aroma diffusers not only spray pleasant fragrances in the room, but also ensure higher humidity.
  • In most of the devices, ultrasound atomises a water-oil mixture into a fine mist and distributes it in the room.
  • The devices hold several hundred millilitres of water and are also suitable for continuous operation.
  • Essential oils can have positive effects on physical and mental well-being.
  • With an integrated lamp, the diffusers spread a pleasant light and even serve as room decoration.

A world full of scents

The natural scent of spruce or pine needles, the beguiling fragrance of colourful rose and tulip fields or the appetising lure of exotic vanilla and cocoa extracts: With an aroma diffuser, you bring the spectrum of this world into your own four walls. No matter in which room and at which time of year, a diffuser provides a pleasant feel-good atmosphere. With the right device, you can eliminate dry air and improve your well-being.

Aroma diffusers produce a fine mist that not only distributes the fragrance oil dissolved in the water in the room, but also ensures higher humidity. Thanks to ultrasound technology, the devices do not contain any harmful substances. Instead, aroma diffusers even bring a health-promoting component. The emerging wellness atmosphere is equally stimulating or relaxing for body and mind.

What is an aroma diffuser used for?

Aroma diffusers are particularly suitable for use in the cold winter months, when the heating air creates a dry indoor climate. In both private and commercial premises, the small, practical devices provide higher humidity, which counteracts the dry air and thus prevents irritating coughs. The diffusers distribute the mist evenly throughout the room, unlike room sprays, for example, which are usually limited to a small area. In addition, the scent of a diffuser oil is far more digestible and less intense. Last but not least, you can use aroma diffusers as decorative elements. Some manufacturers use visually appealing materials and place special emphasis on the design, as the devices are usually placed in living rooms and should not attract negative attention. Discreet lighting, which contributes to the feel-good ambience, is also part of the equipment.

Aroma diffusers can be placed in all rooms of your house. In rooms where children or infants sleep, you should make sure that the devices do not disperse any oils in the air. Although it makes sense to humidify dry air here as well, small children could react sensitively to the scented oils in the water. If you are only interested in air humidification, pure air humidifiers are recommended. With aroma diffusers, as the name suggests, the aroma is in the foreground.

Pro points

  • Even distribution of the fragrance oil
  • Health-promoting
  • Very quiet
  • Increase in humidity
  • Simple operation and cleaning


  • Regular refilling
  • Should only be used with caution if you suffer from allergies

For the well-being of body and mind

Aroma diffusers can provide relief from both physical and psychological complaints. Especially in case of respiratory diseases, irritable cough or dry mucous membranes, the devices have a beneficial effect: blocked and congested noses are cleared by the mist and breathing becomes easier. However, please note that an aroma diffuser does not have the same medical effect as an inhaler. So you should not inhale the mist directly.

The scents emanating from the diffusers can have a stress-reducing effect and help with depressive moods and sleeping disorders. Some oils also improve your concentration. People with sensitive noses should use essential oils, as they emit natural fragrances. Allergy sufferers are well advised to find out about the ingredients in advance, however, as essential oils may well contain allergens.

Aroma diffuser in the living room
When buying an aroma diffuser, you should pay particular attention to the possible lighting, the volume, the material, the extras, the filling quantity and the oils that can be used.

What should I look for when buying an aroma diffuser?

When buying an aroma diffuser, you first have to decide what kind of oil you want to use. There are essential oils as well as synthetically produced perfume oils. The device must be compatible with the oil you prefer. Furthermore, the filling quantity is an important factor. You should select this according to how long you want to leave the diffuser in operation without interruption. Last but not least, you can think about the lighting, the volume and the material; these should correspond to your preference or sensation. The power consumption of most devices is not worth mentioning, as basically all aroma diffusers work very economically.

Good oil for more aroma

The fragrance oils that you use in aroma diffusers differ in the way they are produced. Some are made of natural substances and are composed of various ingredients, while others are produced synthetically. Different fragrances are basically available in both variants. When buying, pay attention to the manufacturer and product specifications.

The natural ones: Essential oils

Essential oils are the most common variety on the diffuser oil market. Their scent is pleasant and calming. The oils are extracted from plant parts and have a positive effect on physical as well as psychological complaints. They are real, water-insoluble oils that leave a film on the inner surface of the aroma diffuser. This means that frequent cleaning is necessary.

Due to their production, the products are usually more expensive than their synthetic counterpart. Nevertheless, when buying, make sure that you buy sustainable products. In addition, the plants from which the essential oils are extracted should have been grown in a healthy environment, without the addition of artificial fertilisers, pesticides or weed killers. This is the only way to ensure the purity of the product and the mist that the diffuser emits. Manufacturer’s claims and certificates should identify the product as one hundred percent pure.

The artificial ones: perfumed oils

The less expensive perfumed oils are synthetically produced fragrances. Because they are usually water-soluble, aroma diffusers are far easier to clean. Note that these artificial oils are only designed as room fragrances. They do not bring any positive health effects. Despite the artificial production, they can cause or intensify allergies.

For full enjoyment: the filling quantity

The filling quantity determines how long you can use the aroma diffuser without interruption or refilling. The water tank of the device not only influences the running time, but also the size and weight of the diffuser. Most products have a water tank with a capacity of 100 to 500 millilitres. You should orientate yourself towards the upper limit if you want the diffuser to spray mist all day long. This requires a tank that holds 300 to 400 millilitres. If you only use the device occasionally, diffusers with small tanks that have a capacity of less than 100 millilitres are also suitable. There are also much larger devices that hold over 1,000 millilitres of water and are best suited if the device is in continuous use and the water tank is not to be refilled regularly.

In any case, refilling the tank is not a major effort and can be done in a few simple steps. Most diffusers atomise 25 to 40 millilitres of water per hour. You can manually adjust the evaporation rate on many devices. If you only want to add a little fragrance to the air in the room, a low evaporation rate is perfectly adequate. The higher setting is recommended if you want to increase the humidity in the room.



Almost every diffuser model has a lamp whose light can be set to different colours. In most cases, you can set the colour intensity and an automatic change. When buying, make sure that the light can also be used independently of the diffuser itself. However, the lighting is only suitable as indirect light, as the luminosity is not strong enough to illuminate the whole room. Dimmable lights can be used as night lights, for example.



Most aroma diffusers work very quietly because of the ultrasonic technology. However, no device is completely silent. You will always hear a slight splash and the spray of the mist. However, the volume is usually below 30 decibels. Some ultrasonic diffusers even go below 20 decibels, making them as quiet as a rustling leaf or snowfall. In some exceptions, the volume of the devices is in the 40- to 45-decibel range, which, however, is only close to a whisper.

The material


Aroma diffusers are usually made of different materials. The water container is made of a thermoplastic such as polypropylene or polyvinyl chloride. The casing is made of glass, ceramic or plastic. The plastic is often modelled on a visually appealing surface, such as wood. It is important that the material used is not susceptible to water vapour.

The extras


The most important extra function of an aroma diffuser is the automatic switch-off. This ensures that the device switches itself off as soon as the water tank is empty. Otherwise, the diffuser could be damaged. With a timer, you can manually set the usage time and determine when the device should be switched on. For this purpose, you can also use the interval mode, in which the diffuser switches on and off regularly. Some devices even have a built-in loudspeaker.

How does an aroma diffuser work?

In common aroma diffusers, water and oil are not heated to produce the water vapour. Instead, almost all devices work with ultrasound. In simple terms, vibrations are transmitted to the water surface. There, capillary waves are formed, which continue to rise until individual drops are formed. The fine drops form the mist that emerges from the diffuser. Since the water has mixed with the oil, the drops also contain the fragrance, which is distributed as a mist in the room. Diffusers with ultrasonic technology work extremely quietly. Moreover, thanks to the ultrasonic technology, hardly any limescale residues remain, which makes cleaning easier for you.

For more cleanliness: Cleaning

You should clean your aroma diffuser at least once a month. If you use essential oils, it does not hurt to rinse the device more often to remove oil residues and limescale. Remember that all substances inside the diffuser are atomised, including limescale and other foreign substances. Use vinegar essence or descaler to descale the unit. Switch on the diffuser and leave it in operation for about 15 minutes so that the device cleans itself. You can remove any residue with a sponge or cloth. If you also want to wash the water tank with dishwashing detergent, use an odourless detergent. Otherwise, the scent of the detergent will also be atomised during the next cycle.

Handling tip

As with any other household appliance that comes into contact with tap water, limescale deposits will also form in an aroma diffuser. Depending on the hardness of the water, this will occur sooner or later. To prevent limescale deposits, use distilled water. Optionally, you can also filter the tap water before adding it to the water tank.

Where do I place an aroma diffuser?

Aroma diffusers should not be placed near electrical appliances or wooden or leather furniture. There should be no furniture that is susceptible to water within a radius of about 40 centimetres. Due to the mist, water residues will accumulate around the unit. Ideal locations are those where a slight air circulation can distribute the mist or fragrance in the room. A place between two windows or an elevated position, such as on a shelf or gallery, is particularly suitable. However, the diffuser should not be placed directly in front of the window, as the mist would condense on the window and not be distributed in the room. In order for it to work correctly, the device must also stand horizontally.

When buying your aroma diffuser, pay attention to whether the device is operated via a mains connection or with batteries. If a cable is required, you will always have to rely on a power socket. With a battery compartment, you are much more flexible.

How to use

When using an aroma diffuser, there are a few things to keep in mind to maintain the functionality of the device:

  • No hot water: Do not put boiling water into the diffuser. This will not speed up the nebulisation process. Instead, you would damage the device.
  • Do not switch on when dry: Leave the unit switched off when the water tank is empty. Most of the time, the automatic shut-off function stops operation as soon as the water is used up.
  • Keep a safe distance: Keep a safe distance from the diffuser. Although the fragrance oil is beneficial, it should not be inhaled directly. After all, the device is not an inhaler.

Are aroma diffusers better than incense sticks and room sprays?

Although this is a matter of taste, the scents of aroma diffusers are usually perceived as more pleasant. Incense sticks work with smoke, which can be harmful to the respiratory system and irritating to the eyes. In addition, they can lead to headaches. Room sprays contain high doses of perfume and smell very intense, often even pungent. In addition, the fragrance does not spread throughout the room, but remains in one spot. Aroma diffusers distribute the scent in the room, increase the humidity to a healthy climate and are beneficial for body and mind. Moreover, they are safer than incense sticks because they switch themselves off thanks to the automatic switch-off.