There are four different types of diffusers:
Nebulizer is a device that doesn't use water or heat as other diffusers. The bottle of essential oil is attached directly to the nebulizer. As a result, the unit uses 100% pure essential oil. The benefit of using this device is a strong concentration of the essential oil. However, it can be noisier than the other devices depending on the specific model in use.
Basically, ultrasonic diffuser is the same as Nebulizer, but it uses water. This makes the mist not so concentrated. This device can be used as a humidifier, that can be very helpful especially in the winter.
An evaporative diffuser is a device that uses a pad or a filter to diffuse the essential oils. One of the disadvantages of this tool is that the light elements of the essential oils will be circulated around the ceiling first and will only come down at the end of the process.
A heat diffuser contains a small candle under a bowl to vaporize a mixture of water and oil. This device is very cheap and doesn't need a special maintenance, however, the heat can change the chemical structure of the oils.
- University of Minnesota, Kate Maher, RN, BSN, How can I inhale essential oils? https://www.takingcharge.csh.umn.edu/explore-healing-practices/aromatherapy/how-do-i-choose-and-use-essential-oils
- England, A. (2000). Aromatherapy and massage for mother and baby. Rochester, Vermont: Healing Arts Press.