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.

The size of HVAC ductwork is based on a friction between the moving air and the duct, and also on the blowers’ ability to counter this friction. A furnace ductwork system can be located in several different places. A system with up-flow application might be located in the basement, while a system with a horizontal application may be found in an attic. Heating ductwork can be used for both heating and cooling purposes by transferring either hot or cold air between two reservoirs. A heating ductwork system can act as an air conditioner by transferring heat from inside to outside. A heating ductwork system can also act as a heater by transferring heat from outside to inside. HVAC ducting is the most important element that needs to be considered while designing a building. Insulated ductwork can be used to eliminate cold air leaking from the ducts and to maintain the insulation performance. This can be done by keeping the full specified thickness of the insulation throughout the entire duct surface. During the installation of a duct system, it needs to be ensured that the duct system does not leak substantially. A rough system, including both supply and return, but without the air handler, should not leak more than 0.03*conditioned floor area (ft 2) per system. The air handler and finished registers must not leak more than 0.07*conditioned floor area (ft 2) per system. HVAC ductwork must be designed and manufactured according to the size of buildings.

HVAC ductwork is used in controlling the internal environment of a building. HVAC ductwork can find applications in both residential buildings and industries. HVAC ductwork is also helpful in basic laboratory experiments. HVAC ductwork should be installed according to design specifications, using installation requirements and procedures from the Uniform Mechanical Code, the Air Diffusion Council, California Residential Energy Efficiency Standards, and manufacturers' specifications. HVAC ductwork should adhere to Underwriters Laboratories, Inc. (UL) 181 standards.