Ducts

Ducts are used to distribute air in some types of air conditioning units. Air ducts are airflows or pathways for passing air to a number of people, equipment or space. A duct system is also known as HVAC ductwork. Duct design also known as HVAC duct design includes laying-out, optimizing, detailing, bending and troubleshooting the loss of pressure in a duct system.

Non-corrosive materials should be used in manufacturing HVAC ducts. Metals such as tin which are non-corrosive are used in duct design. Steel has been galvanized to resist corrosion with the advancement in the field of steel production. Due to this advancement in the steel production, steel has replaced tin in ductworks. There is another advantage and reason of using steel. Steel is less expensive than tin. Therefore, steel is preferred in ductworks.
There are different shapes of ducts e.g. rectangular, round and oval. The rectangular shape is more popular.
Galvanized steel is used in the fabrication of air ducts. It is inexpensive and non-corrosive. It can be molded in any form. It is an advanced form of steel which is used by duct men in the manufacturing of ducts.


Polyurethane can be used to make duct boards. Polyurethane is a polymer which is made by mixing organic materials with a urethane substance. Polyurethane panel board is a rigid board which is a new-water formulated product. Instead of using harmful gases such as CFC, HCFC and hydrocarbon, water is used in the foaming process.

Fiberglass duct boards or panels are made from fiberglass blankets. These blankets are covered with a polymer facing. It serves as good thermal insulator, sound-absorber. It provides silent operation in the HVAC system

Flexible tubing or ducts, also referred as flex ducts are good for cooling and heating applications. It supplies air grilles to a rigid duct system. HVAC installers prevent or minimize turns of airflow by putting limitation to its use in the duct working due to its flexible property. The possibility of pressure loss is among its disadvantages.
There are many components of a duct system such as vibration isolators; take-offs; stacks, boots and head; dampers and air terminals. Vibration insulators are situated at each end of the air handling unit into a duct system. The purpose is to block vibration which is caused by the blowers. Blowers create noise. By blocking vibration, noise is not transmitted. Take-off plays a major role in the transfer of air flow into the subsidiary ducts from the main duct. It a fitting installed into a duct system. Stacks are vertical ducts. Dampers play an important role of regulating air volume flowing to different parts of the duct system. Air terminals act as exhaust air inlets and air outlets.
A duct man or tin-knocker fabricates a duct system. A duct man who does ductwork should be expert in his work. Duct work or duct design involves application of mathematical rules, metal crafting and use of correct materials. Therefore, a duct man should be expert in these fields. He should be well versed about all things related with duct sizing, duct insulation, duct fan, radiator duct, spiral duct, sizing furnace duct systems, air conditioning ducts, etc.