Chimney vs. Flue

A chimney and a flue are integral components of a heating system, each with distinct functions. A chimney refers to the entire vertical or inclined structure that extends above a building’s roofline, designed to carry away the exhaust gases and smoke generated by heating appliances. It encompasses both the outer structural component and the inner passageway or flue. Chimneys are constructed from various materials and often provide structural support to the building. They can have multiple flues, each serving different heating appliances within the same structure.

On the other hand, a flue specifically pertains to the interior passageway or duct within the chimney responsible for transporting combustion gases and smoke from a heating appliance to the exterior. Flues are constructed to be heat-resistant and smooth, ensuring the safe and efficient removal of gases. Typically, each heating appliance has its own dedicated flue that connects to the larger chimney structure.

In summary, while a chimney encompasses the entire structural element designed to vent combustion gases, a flue refers to the inner passageway responsible for directing these gases out of the building. Both are vital components of a heating system, working together to maintain indoor air quality and safety.