G2 Gas Fitter Practice Exam

Which of the following burners is NOT equipped with a mechanical device for supplying combustion air?

1. Natural draft burners

2. Forced draft burners

3. Fan-assisted burners

4. Power burners

The correct answer is: Natural draft burners

Natural draft burners rely on the principle of buoyancy to draw combustion air into the burner. This occurs naturally due to differences in air temperatures and densities within the combustion chamber and the flue, allowing hot exhaust gases to rise and create a vacuum that pulls in air from the environment. Consequently, natural draft burners do not require any mechanical devices, such as fans or blowers, to aid in air intake. In contrast, forced draft burners, fan-assisted burners, and power burners all utilize mechanical means to supply combustion air. Forced draft burners include a fan that pushes air into the combustion chamber, ensuring a steady and controlled supply of air regardless of external conditions. Fan-assisted burners also utilize fans to enhance air supply for combustion, making them more efficient. Power burners use mechanical combustion air supply systems that can precisely control air flow and pressure, contributing to optimal combustion performance. Understanding this distinction between different types of burners is crucial for gas fitters, as it influences the design, installation, and maintenance of combustion systems.