Forced air is a way that a heating or cooling system distributes air throughout a home or structure. The air is pushed through ducts and vents that are connected to a unit that heats or cools the air. A forced air system is actually the part of an HVAC system that distributes both cool and warm air throughout the house. An air handler “forces” air through a network of air ducts and into rooms in the house. A system of vents, blowers, and dampers allow the occupant of each room to control the amount of warm or cool air. Forced air systems are different from central air systems, which apply to the air conditioning unit itself. Forced air systems can be controlled by a single thermostat and supply heat to the entire house by fan-forced air through ductwork. The ducts can go unnoticed as they are typically concealed in crawlspaces, attics, or walls.