Ventilation Noise as an Environmental Problem

FIGURE 5.59 Schemack View o( a typical cf ntraJ 5cation ventilation system, mdtiding a fen ducts, and difYusers/ 

Ventilation noise and the annoyance effects which may result have been a recurring question in recent years for researchers, occupational health services, and various aurhorities. In spite of this, there are still major shortcomings in our knowledge about the links between human effects and exposure to ventilation noise. Current regulations and recommendations are thus based on uncertain principles in certain respects. 

Today there is a pronounced need to take more effective measures against this type of noise. The problem is complicated, however, by the fact that these measures in many instances are unilaterally targered at achieving a lowering of the dB(A) level, which in many cases has resulted in only a marginal restriction of the inconvenience, or even none at all. 

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