Pet dander, pollen, cigarette smoke and mold. These are examples of airborne particles that contanimate the air we breathe inside our homes. While an air purifier has not been proven to eliminate these contaminates, they have been known to greatly reduce the numbers. An air purifier works the same way a fan works. It sucks in air from the back and as it releases it back out into the home, it is purified by one several means. If it is ionized then the machine produces electrically charged air that attatches itself to the airborne particles, UVGI uses UV lamps to steralize the air and the most common types of air purifiers use HEPA filters.