GI ductwork is a series of rectangular conduits and specialized fittings used to transport and distribute conditioned air throughout a building's HVAC system. Made from galvanized steel to prevent rust, these components—including straight ducts, elbows, and transitions—are essential for maintaining proper airflow and pressure in commercial and industrial ventilation.
Rectangular GI ducting is the industry standard for air distribution due to its durability, fire resistance, and ability to be
custom-fabricated to fit tight structural spaces.
- Material and Construction:
- Galvanized Iron (GI): The base steel is coated with a layer of zinc to provide corrosion resistance, ensuring a long service life even in humid environments.
- Locking Mechanisms: Sections are often joined using Pittsburgh locks or slip-and-drive connections to ensure an airtight seal.
- Rigidity: Large panels are typically "cross-broken" (forming a slight X-indentation) to add structural strength and prevent the metal from vibrating or "oil-canning" when the fan starts.
- Key Fittings Shown:
- Straight Duct: The main pathway for air transport.
- Elbows (90° and 45°): Used to change the direction of the air.
- Transitions (Reducers): These connect two different sizes of ductwork, maintaining air velocity as the system branches out.
- Offsets: Used to maneuver around obstructions like beams or pipes while keeping the duct run on its primary path.
- Applications:
- HVAC Systems: Used for supply, return, and exhaust air in office buildings, hospitals, and factories.
