Exhaust fan, also known as negative pressure fan, negative pressure fan, etc., utilizes air convection to keep the indoor environment in a negative pressure state, forming a suction force that continuously sucks in outdoor air and expels the stuffy and hot indoor air, thereby achieving ventilation and cooling effects. It is a type of air conditioning device, also known as a ventilation fan, that is driven by an electric motor to rotate the fan blades and drive the airflow, enabling the exchange of indoor and outdoor air. The purpose of exhaust is to remove indoor polluted air, regulate temperature and humidity, and is widely used in households and public places.