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1、CODE OF PRACTICE CP 153-3:1972 Windows and rooflights Part 3: Sound insulation UDC 69.028.2 + 69.024.98:699.844:534.833.5 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:07:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CP 153-3:1972 This Part of the Code of P
2、ractice has been prepared by a Committee convened by the Codes of Practice Committee for Building on behalf of the Council for Codes of Practice. Having been approved by the Codes of Practice Committee for Building and endorsed by the Council for Codes of Practice, it was published under the authori
3、ty of the Executive Board on 7 April 1972 BSI 02-2000 The following BSI references relate to the work on this Code of Practice: Committee references BLCP/2 and BLCP/2/4 Draft for comment 69/11296 ISBN 0 580 07031 X Foreword This Code of Practice makes reference to the following British Standard Code
4、s of Practice: CP 3: Chapter III, Sound insulation and noise reduction. CP 352, Mechanical ventilation and air conditioning in buildings. To avoid unnecessary delay, information collected for the Code is being issued in a series of separate parts covering particular aspects of the work. The final de
5、cision on whether to assemble the separate parts of the Code, with any necessary amendments and editing, into one volume to form the complete Code, will be taken later. This Code of Practice represents a standard of good practice and therefore takes the form of recommendations. Compliance with it do
6、es not confer immunity from relevant legal and statutory requirements. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 11 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will
7、 be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:07:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CP 153-3:1972 BSI 02-2000i Contents Page
8、ForewordInside front cover Code Drafting Committee BLCP/2ii 1General1 1.1Scope1 1.2Performance and costs1 1.3Types of windows1 2Measurement of sound1 2.1The decibel scale1 2.2Loudness1 2.3The dB(A) scale1 3Control of noise2 3.1Transmission of sound2 3.2Sound insulation2 4The sound insulation perform
9、ance of windows and rooflights3 4.1Effect of openings3 4.2Ventilation3 4.3Performance categories3 4.4Field and laboratory measurements3 4.5Design principles4 4.6Rooflights5 4.7Thermal effects of double windows installed primarily for sound insulation5 5Noise levels5 5.1External noise climate5 5.2Des
10、irable limits for intrusive noise in buildings6 5.3Sound insulation requirements7 5.4Effects of height of buildings7 6The selection of window types and sizes8 6.1Effects of building design and siting8 6.2Curtain walling8 6.3Fixed and openable windows8 6.4Use of double windows9 6.5Automatically contr
11、olled windows9 7Sonic booms9 7.1Effects on windows9 Appendix A Further reading10 Figure 1 Analysis of traffic noise and window insulation11 Table 1 Sound insulation values for closed windows4 Table 2 Range of noise levels at locations in which traffic noise predominates6 Table 3 Tolerable noise leve
12、ls (not exceeded for more than 10 % of the time)7 Table 4 Effect of window size on the sound insulation of 40 dB and 50 dB external walls8 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:07:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CP 153-3:1972 ii BSI 02
13、-2000 Code Drafting committee BLCP/2 windows, doors and frames Mr. H. E. Beckett (Chairman) Mr. E. TuiteBritish Door Association Mr. J. B. Austin, O.B.E., J.P. (Resigned December 1969) British Woodwork Manufacturers Association *Mr. T. Sibthorp *Mr. J. W. Temple Mr. G. H. Merrell Chief Fire Officers
14、 AssociationMr. R. J. Stepney, M.B.E. (Resigned May 1970) Mr. A. WilkinsonCity and Borough Architects Society *Mr. L. C. LomasCountry Architects Society Mr. J. C. CalderheadDepartment of Health and Social Security *Mr. W. Howard (Resigned May 1969) Department of the Environment *Mr. P. B. Whiteley M
15、r. G. H. Wigglesworth *Mr. J. A. GodfreyDepartment of the Environment Building Research Station Mr. R. Goodchild (Resigned June 1970) Department of the Environment Forest Products Research Laboratory *Mr. N. P. Skinner *Mr. J. G. Sunley Dr. H. D. TaylorFire Protection Association *Mr. J. E. Bullough
16、 (Resigned December 1969) Flat Glass Manufacturers Association *Mr. D. R. Goodall *Mr. P. K. NicollGreater London Council Mr. A. A. WinningInstitution of Fire Engineers Mr. K. HewettJoinery Managers Association Limited *Mr. S. R. Armsdon Metal Window Federation of Great Britain *Mr. R. G. D. Brown *
17、Mr. E. J. Collins *Mr. K. R. Peplow (Resigned October 1969) *Mr. H. L. Watts (Resigned November 1969) Mr. E. CorkerModular Society *Mr. H. H. HaynsRoyal Institute of British Architects Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:07:38 GMT+00:00 2006, Unco
18、ntrolled Copy, (c) BSI CP 153-3:1972 BSI 02-2000iii The Drafting Sub-committee BLCP/2/4, Windows, consists of the members of BLCP/2 Committee, marked with an asterisk, under the Chairmanship of Mr. H. E. Beckett with the following additional members: The SecretaryThe Agrment Board Mr. J. E. DouglasA
19、ssociation of Builders Hardware Manufacturers Mr. C. A. Brighton (Resigned May 1970) British Plastics Federation Dr. H. J. Sharp Mr. A. F. Pyne Mr. S. K. Finch British Woodwork Manufacturers Association Mr. R. Slattery (Resigned December 1969) Mr. J. JobsonDepartment of the Environment Miss Margaret
20、 LawDepartment of the Environment Joint Fire Research Organization Mr. P. J. Peters (Resigned January 1969) Metal Window Federation of Great Britain Mr. J. F. R. White Mr. S. LeithScottish Development Department Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06
21、:07:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:07:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CP 153-3:1972 BSI 02-20001 1 General 1.1 Scope This Part of the Code deals with sound transmission thro
22、ugh windows, rooflights and glazed curtain walling. It is to be regarded as an extension, in these particular directions, of the more basic information on sound transmission and insulation in buildings given in CP 3:Chapter III. It also rests to some extent on Building Research Station Digests 38, 1
23、28 and 1291), from which information on noise levels has been quoted. 1.2 Performance and costs Guidance is given on the external noise levels likely to be experienced in various circumstances and on the degrees of sound insulation obtainable with various forms of glazing, so that noise penetrating
24、indoors can be controlled as may be desired. Sound-insulating glazing can, however, be costly, and it is important that the standard of quietness set for any building shall not be unnecessarily high. 1.3 Types of windows In this Part of the Code, windows are referred to as “single” if they are singl
25、e-glazed in single frames, as “double-glazed” if they have twin panes or sealed double-glazing units in single frames, as “coupled” if they have two panes in separate sashes which are normally coupled together, and as “double” if there are in effect two completely separate windows in the same surrou
26、nd, each single-glazed. 2 Measurement of sound 2.1 The decibel scale 2.1.1 The basic unit employed in acoustic measurements is the decibel (dB). The decibel scale is a ratio scale which is also logarithmic. The ratios cover a vast energy range (e.g. 100 dB signifies a ratio of 10 000 000 000 in soun
27、d energy or intensity) but the use of a logarithmic sequence compresses the figures to a reasonable span. Moreover, the decibel scale is closely allied to the hearing response of the ear, besides permitting the units to be added and subtracted instead of having to multiply and divide them as on an o
28、rdinary ratio scale. 2.1.2 For the purpose of measuring noise level, a certain level of sound energy or sound pressure has been standardized as a base level. This base is the threshold of hearing at 1 000 Hz and is designated 0 dB, although a measurable quantity of sound energy is present. A given n
29、oise level on the decibel scale indicates in logarithmic terms the proportional increase in sound energy above the base energy at 0 dB. A sound insulation value in decibels similarly indicates the factor by which the energy content of any noise source should be divided to ascertain the energy level
30、on the receiving side, the actual sum being done by subtracting one decibel value from the other. The logarithmic nature of the scale should always be kept in mind; thus 10 dB represents an energy factor of 10, but 20 dB is a factor of 100, 30 dB is a factor of 1 000, 40 dB a factor of 10 000, and s
31、o on. 2.2 Loudness In terms of energy, the base level of the dB scale for noise is constant at all frequencies, but the ear is not equally sensitive to low sound levels at all frequencies and 0 dB only matches the threshold of hearing at 1 000 Hz. Consequently, the dB scale does not keep in step wit
32、h relative loudness judgements made by the ear if the frequency composition of the noise changes. In the main the ear is less sensitive at low than at high frequencies and for a consistent loudness scale it is necessary to ignore some of the energy present at low frequencies, namely that energy abov
33、e 0 dB which the ear does not hear. 2.3 The dB(A) scale 2.3.1 In the standardized sound level meter an A-weighting network is incorporated to give a frequency response comparable with that of the human ear. Thus the readings on the dB(A) scale indicate the loudness levels of noises rather than their
34、 energy content or pressure levels. In measuring the levels of common types of noise (such as road traffic noise) when a single-figure total is required rather than a full spectral analysis, the present practice is to use the dB(A) scale. Similarly, standards for acceptable noise levels in various s
35、ituations, indoor or outdoor, are generally given in dB(A). 1) H.M. STATIONERY OFFICE, Noise and buildings, Building Research Station Digest 38, 1963; Insulation against external noise, Parts 1 and 2, Building Research Station Digests 128 and 129, 1971. Licensed Copy: London South Bank University, L
36、ondon South Bank University, Tue Dec 12 06:07:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CP 153-3:1972 2 BSI 02-2000 2.3.2 In special cases demanding greater precision, more detailed analysis of the noise (such as octave analysis) may have to be made for matching against standards in the form of
37、noise criteria (NC)2) or noise rating (NR)3) curves. These curves specify limits for each octave frequency band and they have been widely used in setting standards for the acoustical design of mechanical ventilation or air-conditioning systems. However, for the purpose of defining general standards,
38、 the use of single-figure levels in dB(A) has been found much more convenient and technically quite satisfactory in the majority of cases. 2.3.3 Moreover, it has been shown that in dealing with many common kinds of noise, such as traffic noise, a very close approximation to the indoor noise level in
39、 dB(A) can be obtained by subtracting the average sound insulation of the facade in dB from the outdoor noise level in dB(A) as measured with a standard sound level meter. To illustrate this claim a fully analysed example of traffic noise reduced by a window in a brick wall is given in Figure 1, tak
40、en from Building Research Station Digest 129. If, in accordance with this simplified procedure, the average sound insulation of 24 dB shown for the window-wall is subtracted from the total outside level of traffic noise of 77 dB(A), the resultant 53 dB(A) obtained for the average indoor noise level
41、is very close to the true indoor level of 55 dB(A). 3 Control of noise 3.1 Transmission of sound Sound waves in air cause surrounding walls and other elements of a building to vibrate in sympathy. The vibrations are transmitted, with some loss of energy, to the air in adjoining rooms, where a reduce
42、d noise level is set up. Vibration of the structural elements is subject to their natural properties of response or resistance to vibration, and these properties determine the degree of insulation or reduction of the incident sound achieved by the structure. 3.2 Sound insulation 3.2.1 The chief prop
43、erty of any structural element affecting its sound insulation is its mass; the heavier the element the greater the resistance to vibration and the higher the insulation; broadly, each doubling of mass gives about 5 dB improvement. Nevertheless, there are other factors which may modify the insulation
44、 attributable to mass, such as the flexural bending wavelength of the wall or other element, the degree of airtightness or relative area of any air-gaps present, and, in the case of double-leaf construction, the design of the air-space or cavity and the degree of isolation between the leaves. 3.2.2
45、The frequency of the flexural bending wavelength of a panel is known as the critical frequency, because at this frequency and above it sound transmission is increased by matching between the panel wavelength and the corresponding wavelength of sound in air, producing the well known “coincidence-dip”
46、 in the insulation curve. The effect is usually more pronounced in stiff lightweight panel constructions, including window glazing, in which the critical frequency is normally above 1 000 Hz. However, although the effect of coincidence is inherent in window glazing and its nature is detrimental to s
47、ound insulation, its significance is often only marginal and in most cases attempts to modify it are not worthwhile. Nevertheless, in some circumstances special attention may have to be given to suppressing coincidence effects, involving perhaps methods such as vibration-damping edge-mounting of the
48、 glass or, in double windows, using different thicknesses of glass in each pane. 2) P. H. PARKIN and H. R. HUMPHREYS, Acoustics, noise and buildings, Faber but the benefits are obtained only if the windows are fixed or, if openable, are effectively weatherstripped, as the influence of air-paths is o
49、verriding. 3) With fixed glazing, resilient mounting of the glass at its edges, e.g. in neoprene gaskets, generally gives an improvement in sound insulation, particularly in the upper-middle frequency range4). 4) Making windows double improves their sound insulation provided the air-space between the glazings is wide enough. Insulation increases with cavity-width, especially at the lower frequencies. 5) Opening any window, single or double, dra