What is the object placed in an appliance to change the direction of, or retard the flow of, air, air-gas mixtures, or flue gases?

• A. Damper
• B. Baffle
• C. Diffuser
• D. Flue

Answer: (B)

A baffle is an internal flow-directing element used inside appliances to steer or slow down gases. By changing the path of air, air-gas mixtures, or flue gases, a baffle helps gases travel over the heat exchanger or through the intended route, which improves heat transfer and promotes more complete combustion. It can also create the turbulence needed to mix air and gas effectively and prevent concentrations of flow that could cause uneven heating or flame problems.

This matches the definition often used in NFPA 54, which describes a baffle as a device placed in an appliance to change the direction of, or retard the flow of, air, air-gas mixtures, or flue gases. A damper mainly regulates flow by opening and closing passages, not primarily directing flow. A diffuser distributes flow in ducts, not inside the appliance to direct combustion or flue gases. A flue is the conduit for exhaust, not a directing device inside the appliance.