Predicting the sound emission from air-conditioning and ventilating systems

✍ Scribed by D.J. Croome

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 538 KB
• Volume: 9
• Category: Article
• ISSN: 0003-682X
• DOI: 10.1016/0003-682x(76)90011-6

✦ Synopsis

Air-conditioning noise is, of course, only one part of the background noise spectrum .['or a space, but it has become significant over the last decade as more high velocity systems are being installed, and as people have become more sensitive to internal noise sources in buildings well insulated from the external environment. Research has been carried out to investigate the nature and level of sound emitted in rooms served by airconditioning systems. An initial survey measured the sound spectra in 74 university lecture rooms. Fans, motors, vee-belt drives and an airflow system were then installed to serve one lecture room, It was found that the soundpressure level in the room could be predicted by the equation:

where L is the sound pressure level in dB( A ), v is the air velocity in the main duct and N is the fan speed (rpm). Further field studies are being undertaken on man); s),stems in buildings to find out ira general Jormula can be applied in practice.

CASE STUDY 1 : NOISE CONDITIONS IN UNIVERSITY LECTURE ROOMS

In order to ascertain the importance of the problem, a questionnaire was circulated to 49 universities and colleges throughout Great Britain. The questionnaire consisted of ten questions requesting details of any ventilation or air-conditioning 303

Applied Acoustics (9) (1976)--0 Applied Science Publishers Ltd, England, 1976