In a balanced draft system, the forced draft fan is typically:

In a balanced draft system, the forced draft fan is primarily responsible for introducing air into the furnace for combustion purposes, while the induced draft fan helps to remove exhaust gases. The forced draft fan is typically designed to handle cooler, relatively clean air rather than hot combustion gases; thus, it is not designed to manage high temperatures that one might find in the exhaust stream.

The size relationship between the forced draft fan and the induced draft fan can vary based on the design and requirements of the system. However, it's common for the induced draft fan to be larger because it needs to create sufficient suction to pull the combustion gases out of the furnace and through the exhaust system effectively.

These factors contribute to the conclusion that the forced draft fan is often smaller than the induced draft fan, making the assertion accurate in a balanced draft system context. Such design considerations ensure optimal operation and efficiency of the combustion process while maintaining safety and effectiveness in exhaust handling.