What is the role of the fan in a forced draft system?

In a forced draft system, the primary role of the fan is to push air into the combustion chamber. This is crucial for the efficient combustion of fuel as it ensures that an adequate supply of oxygen reaches the fuel, allowing it to burn effectively. By increasing the air pressure in the combustion chamber, the fan helps to enhance the combustion process, leading to improved efficiency and reduced emissions.

In contrast, creating a vacuum is generally associated with draft systems that require drawing air rather than pushing it. Extracting flue gases pertains to other systems where gases need to be vented from the combustion process, typically done by exhaust fans or other equipment. The mixing of fuel and air usually occurs within the combustion chamber itself through burners or mixing devices, rather than directly by the fan's action. Thus, pushing air into the combustion chamber is a fundamental aspect of forced draft systems, promoting better combustion outcomes.