British & International Standards

BS 4718

Standard Number: BS 4718:1971
Title: Methods of test for silencers for air distribution systems
Abstract: Measurement of performance of unit silencers and silencing elements for ducted ventilating and air conditioning systems; aspects considered are attenuation of broad band airborne sound (insertion loss), generation of aerodynamic noise (generated noise level) by, and change in pressure in, air flowing through silencer. Methods measure insertion loss without airflow. Does not apply to silencers providing selective attenuation over narrow frequency bands, or to silencers designed for direct coupling to a fan or for sound insulation of partitions with ventilated openings.
Status: Superseded, Withdrawn
Publication Date: 1971/04/22
Cross References: BS 848:Part 1, BS 848:Part 2, BS 1042, BS 2475, BS 2750, BS 3638, BS 4196, BS 4197,
Withdrawn on: 2003/09/08
Replaced by: BS EN ISO 7235:2003,
Supersedes Draft: 69/27265 DC
Descriptors: Air-distribution systems, Air-conditioning equipment, Silencers, Ventilation equipment, Performance, Performance testing, Noise control devices, Noise control (acoustic), Acoustic measurement, Acoustic testing, Pressure measurement (fluids), Test equipment, Extrapolation, Noise (environmental)