In a forced draft system, where is the fan located?

In a forced draft system, the fan is positioned at the point of air entry. This configuration allows the fan to push air into the combustion chamber or furnace, creating positive pressure within the system. The advantage of this placement is that it helps ensure a consistent supply of combustion air, which is vital for efficient and effective combustion processes.

Positioning the fan at the air intake allows for better control over the airflow, leading to improved combustion efficiency. Since the fan is responsible for forcing air into the furnace, it enhances the mixing of the fuel and air, contributing to a more stable flame and reducing the likelihood of incomplete combustion or harmful emissions.

This setup contrasts with other configurations, such as placing the fan at the stack exit, which would not effectively control the airflow necessary for combustion. Similarly, having the fan within the furnace itself could lead to operational complications and safety concerns, whereas locating it near boiler controls does not provide the necessary airflow dynamics required for proper combustion. Thus, the fan's position at the point of air entry is critical to the functionality of a forced draft system.