Several different industrial fans are required. A type of fan used in the power industry is a draft fan. Draft fans play an important role in thermal power plants because they are responsible for maintaining the flow of gases through the boiler system. There are two types of Draft fans that are used in the power industry; forced draft fans and induced draft fans.

Forced draft fans supply the air necessary for fuel combustion by pushing air through the combustion air supply system and into the furnace. Induced draft fans exhaust all gaseous combustion products or flue gases from the generators to the open atmosphere.

The key difference between a forced draft fans and an induced draft fans is that forced draft fans force outside air into the heating system whereas induced draft fans draw flue gases from the system out into the atmosphere. Both forced draft fans and induced draft fans operate in such a manner that it balances the air system in the boiler to make the combustion process efficient.