ID FAN / Induced Draft Fan refers to the Induced Draught Fan as a type of fan that produces or generates negative pressures. This pressure is created inside the combustion air systems like that of kilns, etc. In coal-fired boilers, they are connected and present in the path or route of flue gas between the chimney and the electrostatic precipitator. They are also used along with that FD fans for affecting the pressure values which are less than that of ambient air pressures.