HVAC ductwork includes pipe or closed conduits made of sheet metal, fiberglass board, or other suitable material for conducting air to and from an air handling unit. HVAC is an acronym for heating, ventilation, and air conditioning. HVAC systems regulate the temperature inside a building, with the use of heating and cooling systems, wall and ceiling ducting, and other HVAC technologies. There are several types of HVAC ductwork. Examples include air conditioning ductwork, heating ductwork, furnace ductwork, and insulated ductwork. Air conditioning ductwork uses malleable ducting pipes that are placed in the ceiling. These pipes route the cool air through ceiling vents or “ducts” in each room. The pipes which distribute air in the room are called air conditioning ducts. The distribution system is made of an HVAC ductwork air return supply, filters, dampers and registers. There are numerous methods of designing a ducted heating or cooling system. Care is taken when making HVAC ductwork design in order to provide maximum efficiency. HVAC ductwork works on the principle of conduction and radiation. Other HVAC ductwork types are commonly available.