Gas Fitter Practice Test

What is the role of an induced draft fan in a forced air furnace?

1. To increase humidity

2. To remove combustion gases

3. To enhance air intake

4. To regulate temperature

The correct answer is: To remove combustion gases

The role of an induced draft fan in a forced air furnace is to remove combustion gases from the furnace. This component is crucial for ensuring that potentially harmful exhaust gases, such as carbon monoxide, are effectively expelled from the system and do not enter the living space. By creating a negative pressure within the combustion chamber, the induced draft fan pulls combustion gases and by-products through the venting system and outside of the home, enhancing safety and compliance with ventilation requirements. In terms of the other options, the induced draft fan does not function to increase humidity, enhance air intake, or regulate temperature. Increasing humidity is typically managed by a humidifier, enhancing air intake involves a different set of components, and temperature regulation is primarily the role of the thermostat and the furnace's heating elements rather than the draft fan itself.