In terms of heating systems, what does the term "draft hood" refer to?

The term "draft hood" specifically refers to a component designed to manage the airflow of combustion gases and ensure safe venting from heating systems. Its primary role is to prevent backdraft, which occurs when exhaust gases re-enter the system or building rather than being carried outside. This is critical for maintaining the safety of the heating system and preventing the accumulation of harmful gases like carbon monoxide in living spaces.

A draft hood accomplishes this by allowing for proper venting and maintaining draft pressure within the flue system. By ensuring that gases flow in the intended direction, it protects the integrity of the heating system and the safety of the occupants.

The other options, while related to heating systems, do not accurately describe the function of a draft hood. For example, regulating temperature pertains to different components like thermostats or control valves, and thermal control relates to managing the heat levels within a system rather than the exhaust flow. A part of the exhaust system could include various components, but it is the specific function of preventing backdraft that defines the draft hood.