Final answer:
A barometric damper is used to regulate airflow in a chimney or flue system based on changes in barometric pressure.
Step-by-step explanation:
A barometric damper is a device used in buildings to regulate airflow and control the draft in a chimney or flue system. It works by automatically adjusting the opening of the flue based on changes in barometric pressure. When the pressure inside the building is lower than outside, the damper opens to allow air to flow out of the building. On the other hand, when the pressure inside is higher than outside, the damper closes to prevent air from flowing back into the building.