Flue

A Flue is a duct, pipe, or chimney for conveying exhaust gases from a fireplace or water heater to the outdoors. As combustion products contain carbon monoxide and other dangerous compounds, proper 'draft', and admission of replacement air is imperative. Building codes, and other standards, regulate their materials, design, and installation.

WIKIPEDIA ENTRY FOR FLUE

Flue Picture   Flue 2 Picture