A flue system is a series of pipes or ducts that safely vent exhaust gases from appliances like furnaces, boilers, or fireplaces to the outside atmosphere. These systems are essential for maintaining indoor air quality and preventing harmful gases, such as carbon monoxide, from accumulating inside buildings. Flue systems can be made from various materials, including metal and ceramic, and are designed to withstand high temperatures. Proper installation and maintenance are crucial to ensure they function effectively and comply with local building codes, helping to protect both people and property from potential hazards.