What is the purpose of a draft inducer fan in high-efficiency furnaces?

The purpose of a draft inducer fan in high-efficiency furnaces is primarily to help create proper venting and exhaust of combustion gases. This fan assists in maintaining the correct airflow for the combustion process, ensuring that exhaust gases are efficiently removed from the heat exchanger and vented outside. This is crucial because improper venting can lead to the buildup of harmful gases, such as carbon monoxide, within the home environment.

In high-efficiency systems, the draft inducer creates a negative pressure in the flue, enabling the furnace to operate safely and effectively. Proper venting prevents any potential backdrafts that could lead to the re-entry of dangerous gases into the living space. This system is essential for maintaining safety and compliance with building codes that regulate the venting of combustion appliances, ensuring that the furnace operates at optimal efficiency.