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.
Chimney and flue types: 1  Masonry (brick or stone fireplaces and chimneys) with or without tile-lined flue. 2  Reinforced concrete chimneys. 3  Metal-lined flue: Double or triple walled metal pipe running up inside a new or existing wood-framed or masonry chase.