The Homedics Total Comfort Deluxe Ultrasonic Humidifier disperses visible cool mist. ts home décor design is great for large bedrooms and family rooms up to 400 sq. ft. The .97 -gallon top-fill tank is easy-to fill and provides up to 45 hours of runtime with auto-shutoff protection when the water runs out. Homedics Ultrasonic Humidifiers have high-frequency technology that converts water into a fine evenly dispersed mist. Choose from 3 cool mist settings and a variable dial that helps to maintain the desired room humidity. Enjoy aromatherapy benefits with the included essential oil pads and aroma tray.