Using your K&N HVAC filter is easy. First, turn off your HVAC system before installing the filter. Place the 14 x 25 x 1 filter in the designated filter slot in your HVAC unit. Make sure it fits snugly. When it comes to maintenance, check the filter regularly. If it looks dirty, it's time to clean it. To clean, gently remove the filter from the unit. Wash it with mild soap and lukewarm water. Rinse thoroughly to remove all soap. Let it dry completely before reinstalling. Don't use harsh chemicals or abrasive materials as they can damage the filter. With proper care, your K&N filter will last the life of your HVAC unit.