Dyson Purifier Cool Gen1 purifying fan. Automatically senses and captures pollutants to purify your whole room. Fully-sealed to HEPA standard – what goes inside, stays inside. Whole-room purification: Only Dyson purifiers have Air Multiplier technology, to draw in distant pollutants and project 290 litres of purified air throughout the room. Cools you in summer: The long range projection and powerful stream of purified airflow you cools you down. Diffused mode: Purifies without cooling you. Airflow is diverted through the back of the machine, maintaining effective purification.