A damper on an AC unit is a device that is used to regulate the airflow of air in a system. It is typically used to control the temperature of a room or area by regulating the amount of air that is being circulated. Dampers are usually made of metal and are usually located near the air handler or furnace. They are designed to open and close in order to control the amount of air that is being circulated. This allows the user to adjust the temperature of the room or area to their desired level. Dampers are also used to prevent the air from entering or leaving the system, which can help to reduce energy costs. Additionally, dampers can be used to control the amount of air that is being circulated in order to improve the air quality in a room or area. By controlling the amount of air that is being circulated, the user can reduce the amount of dust, pollen, and other allergens that are present in the air.