The Trion Console 350 Electronic Air Cleaner is a portable room air cleaner. This unit contains 2 prefilters, 2 collector cells and 2 charcoal after filters. Maintenance on the Trion Console 350 Electronic Air Cleaner consists of washing out the collector cells and prefilters on a monthly basis and replacing the charcoal filters every 3 months. The charcoal filters must be replaced more often if you have a heavy smoker in the space.