Definition – Terminology
Flue and exhaust gas ducts

Chimney: vertical flue designed to carry away the products of combustion of common fuels (coal, heavy or light domestic fuels, liquefied hydrocarbons, gas, wood).

The flue originates in a room at the same level as the generator, at foundation level or at an intermediate level between the room and the foundation (figure 1).

This duct terminates at the upper outlet into the atmosphere (with the exception of accessory devices, such as soot collectors, convergent or other devices).

Multi-fuel pipe: if the pipe can evacuate the combustion products of the various fuels listed above, it is said to be a "multi-fuel" pipe.

Single-fuel or special flue: if the flue can only evacuate the combustion products of one of these fuels, it is called a "single-fuel" flue. This type of duct is also called...