Aims of an Air-Handling System, Including the Unit and Ductwork

The main objectives are

• Contaminant removal from the indoor space and associated processes

• Supply of safe cleaned and/or treated air for the occupied spaces

• Control of thermal and pressure conditions in treated spaces in a safe, reliable, and energy-efficient manner

Aims of ductwork design are

• Transport of air to and from treated (conditioned) spaces

• Distribution and control of airflows to and from the treated spaces with optimum life-cycle costs.

The air-handling processes should be arranged to take into account the thermal, aerodynamic, and acoustic factors; air quality; moisture control; and cleanliness and other hygiene aspects.

These issues relate certain requirements of the layout of the air-handling system and individual units, including the question of whether to select central­ized or decentralized systems, and the number of units required in the building.