Forced Draft Fan is a type of a fan supplying pressurized air to a system. In the case of a Steam Boiler Assembly, this fan is of great importance. As we know, for a Steam Boiler to generate steam, combustion must occur, be it any fuel (wood/coal/rice husk/pet coke/LDO/Furnace oil) and for combustion to exist one of its three main requirements, is the air.