An external flue, in the context of a wood-burning stove, refers to the part of the stove's ventilation system that extends outside the building to expel combustion byproducts. It is also known as a chimney or flue pipe.
Wood-burning stoves produce smoke, gases, and particulate matter during the combustion process. An external flue serves as a pathway for these byproducts to exit the stove and be safely vented outside. The flue pipe connects to the stove's exhaust outlet and extends through the wall or roof of the building.
Here are some key points about an external flue on a wood-burning stove:
Material: Flue pipes are typically made of stainless steel or other suitable materials that can withstand high temperatures and corrosive combustion byproducts.
Clearances: The flue pipe must maintain proper clearances from combustible materials, such as walls or ceilings, as specified by local building codes and the stove manufacturer's instructions.
Insulation: External flues may require insulation, especially when passing through walls or ceilings. Insulation helps prevent heat transfer to combustible materials and maintains the efficiency of the flue system.
Height and Termination: The flue pipe should extend above the roofline or away from any nearby obstructions to ensure adequate draft and prevent downdrafts. The termination point should be equipped with a chimney cap or rain cap to prevent water entry and to minimize the intrusion of animals or debris.
Cleaning and Maintenance: Regular cleaning and maintenance of the flue pipe are necessary to remove creosote buildup, which can pose a fire hazard. Creosote is a combustible substance that forms when wood burns and condenses along the walls of the flue.
Proper installation and maintenance of the external flue system are crucial to ensure the safe and efficient operation of a wood-burning stove. It is recommended to consult a professional or chimney sweep experienced in wood-burning stoves for installation and regular inspections to ensure compliance with safety standards and regulations.