Flue
Definition: What is a Flue?
Flue spaces are used to combat fires. They form clear vertical lines of sight from the floor up to the ceiling within rack storage areas. Spaces between rows of storage in the direction of loading are known as transverse flues. Spaces between rows of storage perpendicular to the direction of loading are known as longitudinal flues.
In cases where there are no in-rack sprinklers positioned below every storage tier, flue spaces allow heat from a fire to vent vertically. As a result, ceiling level sprinklers (and any other sprinklers) can operate efficiently to slow down the spread of fire horizontally. Flues also allow sprinkler water to reach the base of the fire.
In addition, material-handling machinery uses gas- or diesel-powered engines. These engines exhaust all kinds of smoke and waste. Warehouses use the flue also as a duct to remove smoke and waste gases produced by such fuel-burning installations. Flues help combat combustion-generated fly ash.