The Coway Airmega 400 model features smart mode (auto, sleep, eco) and real-time air quality monitoring, so you can rest assured that your air is being cleaned at all times. The Coway Airmega 400 is designed to accommodate room sizes up to 1,560 square feet and it cleans the air two times in one hour. Coway Airmega draws contaminated air from two sides and pushes filtered air out the top of the unit, cleaning the air you breathe faster and more efficiently. The air filter indicator tells you when the two Max2 filters need to be replaced, and the pre-filters need to be cleaned for maximum efficiency, based on how much air they have processed. The easy-to-clean pre-filter captures large particles like hair, fur and dust in its micromesh, so Max2 filter can work more effectively. The Max2 filter—a combined activated carbon and a Green True HEPA filter—captures and reduces up to 99.99 percent of particles 0.01 microns in the air, including pollen, pollutants, and other allergens. It also reduces more than 99 percent of volatile organic compounds and reduces fumes such as NH3 and CH3CHO. With its Smart Mode feature, the Coway Airmega automatically adapts to its surroundings by adjusting fan speeds based on the room’s air quality. That means your unit is energy efficient without compromising efficacy. When the air quality in the room remains purified for 10 minutes or more in smart eco mode, Coway Airmega turns the fan off to conserve energy. When Coway Airmega’s built-in light and pollution sensors detect that the room has been dark and the air is clean for three minutes, Coway Airmega reduces noise and power consumption. Coway Airmega’s pollution sensor communicates indoor air quality in real-time. The brightly colored LED ring lets you know how clean or dirty your indoor air is every minute of the day.