The Seasonaire has Triple Air Purification that cleanses and purifies the air around you. The Hepa Filter removes 99.9% of all dust, allergens, mold spores, pet dander and pollen that are larger than 0.3 microns. Next the UV Purification Chamber kills 98% of all airborne bacteria that passes through it. Then the Multi-Polar Ionizer will ionize the air and to give a fresh mountain like scent. A built-in humidifier adds moisture. Use with or without the heater