Gas Fitter Practice Test

What is the purpose of baffles in a hot water boiler?

1. To reduce water flow

2. Clean boiler tubes

3. Premix air and gas

4. Slow hot flue gases flow

The correct answer is: Slow hot flue gases flow

Baffles in a hot water boiler serve the purpose of slowing down the flow of hot flue gases. This is crucial because by extending the time that flue gases remain in contact with the heat transfer surfaces, baffles enhance the heat exchange process. As the hot gases flow through the boiler, they transfer their heat to the water more effectively, resulting in higher efficiency and better heating performance. The design of baffles creates a turbulent flow path, which further increases the surface area contact between the hot gases and the boiler surfaces, leading to improved heat transfer. Therefore, the presence of baffles contributes significantly to the overall efficiency of hot water boilers by ensuring that the maximum amount of heat is extracted from the combustion gases before they exit the system. In contrast, the other options relate to different functions that are not directly linked to the primary role of baffles in a hot water boiler system, making them less relevant in this context.