What is the term used for an area in which fuel or a gaseous substance is burned?

The term for an area in which fuel or a gaseous substance is burned is known as the combustion chamber. This is a critical component in various engines and heating systems where the combustion process occurs. The combustion chamber is designed to contain the mixture of fuel and air, allowing for efficient burning and energy release.

In engines, for instance, the combustion chamber is where the fuel-air mixture ignites, producing the high-pressure gases that drive the pistons. In heating systems, the combustion chamber is where the fuel is burned to produce heat, which is then transferred to water or air for distribution.

The other options relate to different functions within gas systems but do not refer to the area of burning fuel directly. A storage chamber is primarily for holding fuel before it is used, a control chamber generally refers to areas that regulate the flow or pressure of a substance, and a draft chamber is associated with airflow or ventilation rather than active combustion.