Using your K&N HVAC air filter is easy. First, turn off your HVAC system. Remove the old filter and replace it with your new K&N filter, making sure it's properly seated in the filter slot. When it comes to maintenance, check the filter every three months. If it looks dirty, it's time to clean it. To clean, gently vacuum the filter to remove large debris. Then, soak it in a mild detergent and warm water solution for about 15 minutes. Rinse it thoroughly with clean water and let it air dry completely before reinstalling. Avoid using harsh chemicals or high - pressure water as they can damage the filter. With proper care, your K&N filter will serve you well for a long time.