Ductwork, ducts, or ducting, are conduits, or tubes, that typically form part of a ventilation system, used to convey air throughout a building. An example of a simple elementary duct is a fireplace chimney, used to convey smoke to the outside. Hard pipes used to transfer water or gas are not classed as ductwork.
Duct design involves planning (laying out), sizing, optimising, and detailing. Ductwork should be among the first items to be considered when designing a new building because of its importance in the overall utility of the building, and the need to integrate complex duct routes with other elements of the overall design. This can be particularly difficult where structural elements pass through building services spaces, such as the down stands of beams, or where ducts have to pass through other elements of the building.
- Air should be conveyed as directly as possible to save space, power and material.
- Sudden changes in directions should be avoided. when not possible to avoid sudden changes, turning vanes should be used to reduce pressure loss.
- Diverging sections should be gradual. Angle of divergence <= 20 degree.
- Aspect ratio should be as close to 1.0 as possible. Normally, it should not exceed 4.
- Air velocities should be within permissible limits to reduce noise and vibration.
- Duct material should be as smooth as possible to reduce frictional losses.
- FUNCTION OD DUCT
- CLASSIFICATION OF DUCT
- ECONOMIC FACTORS INFLUENCING DUCT LAYOUT
- DUCT DESIGN METHOD
- DYNAMIC LOSSES & ITS DETERMINATION
- REQUIRMENT OF AIR DISTRIBUTION SYSTEM