Standard rectangular duct sizes. Ducts are the passages that are used in heating, air conditioning, and ventilation to deliver and remove air.
The airflow may include supply air, return air, or exhaust air. Ducts are usually used to deliver ventilation air as a part of the supply air. The air ducts maintain indoor air quality and thermal comfort.
Standard rectangular duct sizes
The ducts are important for the ventilation purpose of malls and halls because there they need to maintain the air quality to ensure the comfort of people and help to regulate.
Moreover, the duct system is also called the ductwork, whenever a new hall or mall is built the duct system is properly planned, the sizing, optimizing, detailing, finding the pressure losses through the duct system.
There are a few types of standard rectangular ducts, let’s explore them in greater detail below.
The galvanized mild steel is used as the standard and is one of the most common materials used in fabricating ductwork because it has the zinc coating of the metal that prevents rusting and deducts the cost of painting. At the time of installation, the ducts are usually wrapped around in fiberglass or lined with fiberglass blankets.
The Aluminum ductwork
The aluminum ductwork is very lightweight and easy to install. Aluminum ducts can be easily maneuvered and molded into any shape in the shop or on the site.
The design of the ductwork begins with the tracing on the aluminum pre-insulated panel of the duct outline. Normally the pieces are then cut at 45°, bent if necessary, to get various fittings (i.e. elbows and tapers and eventually assemble with glue.
Aluminum tape is applied to all seams where the aluminum foil’s exterior surface has been cut. To fit different fitting requirements, a variety of flanges are available. With sealant, all internal joints are sealed.
For the development of round spiral ducts, aluminum is often used, although it is far less common than galvanized steel
Fiberglass duct board
Fiberglass duct board have built-in thermal insulation, it also absorbs sound through the interior lining, helping to ensure the HVAC system works quietly
By using a straightedge as a guide, the duct board is shaped by a sliding specially crafted knife along with the sheet. A blade automatically slices out a groove having a side of 45° that does not fully reach the depth of the duct board, thereby creating a thin section serving as a hinge.
The duct board can be shaped into a rectangle or square or another shape with folds of 90° each, making the shaped duct form the desired size of the fabricator. The duct is then closed with staples that are special aluminum or similar metal-blacked tape which are outward shaped.
Cutting rectangular duct to length