What is a primary function of induced draft fans in a steam system?

Induced draft fans play a crucial role in steam systems by enhancing the combustion process in the furnace. Their primary function is to pull draft through the furnace, which helps in effectively managing the air-to-fuel ratio needed for efficient combustion. By creating a negative pressure within the combustion chamber, these fans ensure that the products of combustion, along with excess air, are drawn through the system and expelled through the stack.

This controlled draft not only improves the efficiency of the fuel being burned but also aids in maintaining the desired temperatures within the furnace. Proper draft is essential for maximizing heat production and ensuring complete combustion, which ultimately leads to higher system efficiency and reduced emissions. In contrast, the other functions presented are not typical roles of induced draft fans in steam systems.