The answer to 'how does air filter work' is that an air filter is a device that removes contaminants and particles from the air as it passes through. Air filters are typically made of pleated paper, fiberglass, or other materials that trap dust, pollen, pet dander, and other airborne particles before they can circulate through your home's HVAC system and living spaces.
As air is drawn through the filter, the media inside traps the particles, allowing clean air to pass through. Over time, the filter becomes clogged with these particles, reducing airflow and the filter's efficiency. That's why it's important to replace your air filter regularly, usually every 1-3 months, to maintain good indoor air quality and keep your HVAC system running efficiently.