Whether it's a steam-heat winter or a long, dusty summer, install a new humidifier filter or evaporative wick in your humidifier before your dry season starts. Get rid of the limescale and bacteria in your old unit with a humidifier cleaner, and control indoor dust and particulates with an air purifier. Grainger humidifiers and humidifier replacement filters help keep ambient moisture levels up, and your indoor air clean and fresh.