How Often Should a Diffuser Actually Run?

Running a diffuser continuously from morning to night is neither necessary nor pleasant. Scent fatigue sets in quickly — after twenty minutes or so your nose stops registering a fragrance you are sitting inside of.

Use the intermittent mode

Most units offer a mode that runs for thirty seconds and pauses for thirty. This uses noticeably less water and, more usefully, keeps the scent perceptible because your sense of smell gets a chance to reset between bursts.

Sessions, not marathons

A thirty to sixty minute session is enough for most rooms. Two short sessions — one in the early evening, one before bed — will do more than four hours of continuous running, and your oils will last considerably longer.

Ventilate anyway

A diffuser is not a substitute for opening a window. Run it in a room that gets some air movement, and switch it off before you leave the house.