Which of the following is not a requirement for a fire damper?

A fire damper is a crucial component used in HVAC systems designed to prevent the spread of fire and smoke through ductwork. The correct answer highlights that fire dampers do not need to be part of a listed grease extractor. While fire dampers are essential for various building safety codes and may be used in areas where grease extractors are also employed, there is no explicit requirement mandating that they must be included as a part of the grease extractor system itself.

The other requirements outlined in the options reflect essential standards that apply to fire dampers. They must be accessible for maintenance because regular checks and serviceability are critical to ensure they function correctly when needed. Furthermore, annual testing is necessary to verify that the fire dampers will operate effectively during a fire event. Lastly, installation in all ductwork is a standard requirement, specifically in certain areas of commercial or industrial buildings where fire safety protocols necessitate dampers to limit the spread of fire and smoke.

Thus, option A stands out as the one that is not inherently required for a fire damper, making it the correct choice.