The exact duration of an air freshener's scent will vary depending on the product type, the room size, and the airflow. For example, aerosol air fresheners typically disperse their fragrance more quickly than plug-in air fresheners, which release a steady stream of aroma beads over a longer period.  Similarly, spraying a large amount of air freshener into a small space will cause the scent to be quickly overpowered, while a light mist in a large room will allow the fragrance to linger for hours. Most air fresheners will provide sufficient fragrance for about 2 to 6 hours.