Duct (HVAC)

Ducts are long tubes used to move air from one place to another. They are often used to help make sure that a house stays warm or cool inside, depending on the season. The air inside the house comes from the HVAC (heating, ventilation, and air conditioning) system, which works like an invisible machine. The air is warmed or cooled by the HVAC and then is moved through the ducts to different parts of the house. The air comes out of vents that are usually in the floor or ceiling, so you can feel the warm or cool air.