How electric diffusers work: do they need water?

Some electric diffusers use water to carry fragrance into the air. Others diffuse fragrance directly. The method depends on the device, so check how yours works before filling it.

Understanding the difference makes it easier to choose a diffuser and use it correctly.

How does an electric diffuser work?

An electric diffuser releases fragrance into the air. Some disperse a fine mist from a mixture of water and a compatible oil. Others use heat to help fragrance evaporate, or air to disperse it directly.

The power source alone does not tell you how a diffuser works. What matters is the mechanism inside it.

Does an electric diffuser need water?

Not always.

Water-based diffusers have a tank that you fill with water and the recommended amount of a suitable oil or fragrance. The device then disperses a scented mist.

Waterless diffusers use fragrance without a water tank. Cold-air diffusers are one example.

Before adding water, read the instructions for your device. A diffuser designed to use fragrance directly should not be filled with water.

How does a waterless electric diffuser work?

A waterless diffuser releases fragrance without mixing it with water. The mechanism varies between devices.

Cold-air diffusion uses air to break the fragrance into a fine mist that disperses through the surrounding space.

Celestial's Vessel 01 uses this method. It works without water or heat.

What is cold-air diffusion?

Cold-air diffusion uses air pressure to break fragrance into fine droplets and release them into the room.

There is no water to add and no need to heat the fragrance. Use a formulation made for this type of diffuser, following the device's instructions.

Water-based and waterless diffusers

Water-based diffusers: You add water and a compatible oil or fragrance to the tank before switching on the device.

Waterless diffusers: You use a compatible fragrance directly. Cold-air diffusion is one way of doing this.

The choice comes down to where you will use the diffuser and the filling and cleaning routine you prefer.

When does a waterless diffuser make sense?

A waterless diffuser can suit someone who would rather refill a fragrance bottle than prepare a water tank each time.

Some models are portable and suitable for a home, office or car. Check the intended uses of the particular device before moving it between spaces.

For help with setup, scent intensity and timers, read our guide to using an aroma diffuser.

Frequently asked questions

Before you fill the diffuser

Check whether your device uses water, heat or cold-air diffusion. Choose a compatible fragrance and follow the filling instructions for that model.

If you prefer a diffuser that works without water or heat, you can read more about Vessel 01.