An aromatherapy diffuser is any device that disperses the scent of essential oils into the air. The type of essential oil diffuser you choose will depend on how you plan to use it and what effects you want to achieve. For example, some diffusers use heat, but some sources (not all agree) believe that heat may change certain components of essential oils, reducing their therapeutic benefit.
Let's look at the types of aromatherapy diffusers.
A nebulizing diffuser, or aromatherapy nebulizer, pumps air through a chamber filled with essential oils. A nebulizer uses no heat and no water, and converts the essential oil into microscopic droplets that stay in the air for a long time.
Nebulizers produce the strongest aroma and effectively disperse essential oils while maintaining their therapeutic properties.
Cold air diffusers atomize a mixture of cold water and essential oils, breaking up molecules into a microscopic mist. Many cold air diffusers use ultrasonic technology to create a high frequency that atomizes the water and oils.
For a strong diffusion, this option is the next best choice after a nebulizer.
Aromatherapy vaporizer is a somewhat nebulous term that's applied to a variety of devices (including ones that diffuse the scent of herbs). One type of aromatherapy vaporizer has a diffusing cartridge, on which you place the essential oil. A stream of air then flows through the cartridge and diffuses the essential oil without using heat.
Other types of vaporizers do use heat. Some vaporizers use water, and some don't.
Aromatherapy oil burners or oil warmers use either candles or electricity to create heat that disperses the scent of essential oils into the air. Candle diffusers are popular and can add ambience to a room. Electric oil burners offer the safety advantage of no flame and also come in many decorative types
A similar option is a lamp ring. The terra-cotta ring has a grooved lip that sits directly onto a light bulb. The lip holds essential oil, and the heat from the light bulb heats the oil, dispersing it into the room.
A fan diffuser is efficient, quiet, and easy-to-use. A small fan blows air through a pad containing essential oils. This type of essential oil diffuser is best suited to small spaces.
With a reed diffuser, you place essential oil in a bottle, place the reeds in the essential oil, and the scent diffuses through the reeds.
Terra cotta diffusers come in the form of aromatherapy pendants you can wear, as well as in the form of tabletop terra cotta pieces. The porous surface of terra cotta diffusers disperses the scent of essential oil into the air.
If you don't have a diffuser, you can disperse essential oils in these ways: