More system — and equipment-specific questions will be dealt with in more detail in the Systems and Equipment volume. Examples include
System hygiene and cleanliness, and maintenance issues: General requirements presented in ENV 12097 and prEN 13779 apply.
Dampers in air handling units and air distribution systems: Attention has to be paid to reducing the leakages, in accordance with EN 17.51. Dampers used in mixing sections of air-handling units must fulfill additional requirements, in accordance with prEN 13053.
Mixing in air-handling units and air distribution systems: Some main principles are presented in Section 9.4. However, air mixing is a complicated process under strong development. Also, the need for major improvements in the equipment has been identified very recently in connection with the standardization work in CEN (prEN 13053).
Air terminals and functional factors affecting the air handling systems: Some basic principles are presented in Chapter 8. However, more attention has to be paid to minimizing the leakages and to sound attenuation.
Materials and corrosion protection: These issues are covered in greater detail in System and Equipment. Also, from the hygienic point of view, this issue is growing in importance. Applications with high hygiene requirements are rapidly increasing due to automation of processes.
Flexible ducts (or tubes) and their pressure drops at various flow rates both when extended and when compressed; connection to metal sheet ducts.
Ducts of other materials than metal sheet (plastic, glass fiber wool and aluminium sheet, ceramics, glass, etc.)
Movable or swinging ducts and associated pressure drops in different positions.
Dampers for air ducts handling dust.
Fan selection for air and gases that are dust laden or contain corrosive gases or vapors.
Silencers in air-handling units and air distribution systems.
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