chimney

A chimney is a stone or brick construction which contains one or more flues. A flue is a passage within a chimney through which smoke, fumes, and gases rise. A flue is lined with clay or steel to contain the combustion wastes. By channeling the warm, rising gases, a flue creates a draft that pulls the air over the fire and up the flue. Each heat source, such as a fireplace or furnace needs its own flue; however, several flues may occupy a single chimney.