What does an induced draft fan do in a boiler system?

An induced draft fan plays a critical role in the operation of a boiler system by pulling flue gases out of the furnace. This function is essential for maintaining the efficiency of the combustion process. By creating a negative pressure within the combustion chamber, the induced draft fan ensures that the combustion gases are effectively removed from the boiler system, facilitating the safe and efficient expulsion of exhaust gases through the chimney or stack.

This process helps to ensure that sufficient fresh air is drawn into the combustion chamber for optimal burning of the fuel, thus improving heat generation. Additionally, effective removal of flue gases helps to minimize the chance of backdrafts or buildup of harmful gases within the boiler, contributing to the overall safety and operation of the system.

The other options, although related to boiler function, do not accurately describe the purpose of the induced draft fan. For example, pushing air into the furnace is typically the role of a forced draft fan. Increasing water flow to the boiler generally involves pumps, and regulating water levels is managed by level controls and other devices in the system.