Although Chicago is known as the Windy City, it is in fact less windy than many other major American cities. Average wind speeds range from 8 miles per hour (13 km/h) in late summer to 12 miles per hour (19 km/h) in spring months.
A flue is a duct, pipe, or opening in a chimney for conveying exhaust gases from a fireplace, furnace, water heater, boiler, or generator to the outdoors.
The damper is actually a flap inside the flue, which can be adjusted manually to allow smoke to escape or air to enter. The damper is often made of metal or ceramic so that it can tolerate the heat of the fire.