Flat galvanized ducts
Galvanized air ducts are the first generation of their type made in two models; flange type (English) and sliding type (American). The closer quadrangle ducts are to a square, the more efficient they will be, but use is usually made of rectangular ducts due to the lack proper space and execution problems.
Since the air passing through a duct is usually cooler than the ambient dew point, and galvanized ducts are good thermal conductors, to prevent the air vapor condensation, the duct surface should be fully insulated with elastomeric insulators that are much more efficient than those made of glass wool, rock wool or polyethylene.
Round galvanized ducts (merits)
- Reduced pressure drop
- Strong with nice appearance
- Reduced noise
- Capable of being made of steel for hygienic environments
Although the spiral duct’s outer surface is embossed, it is perfectly smooth on the inside and does not cause any pressure drop along the air/fluid path. And, since these ducts have spiral seams, they are quite strong and minimize air leakage through proper air sealing.
To divide air, convert duct sections and redirect routes in galvanized duct systems, use is made of different-size/-shape joints/splits; connector or flange to connect ducts/parts, and ceiling/wall supports to install the system.