1、BRITISH STANDARD BS 5502-32: 1990 Incorporating Amendment No. 1 Buildings and structures for agriculture Part 32: Guide to noise attenuationBS5502-32:1990 This British Standard, having been prepared under the directionof the Farm and Horticultural Buildings Standards Policy Committee, was published
2、under the authority of the Standards Board and comes into effect on 31 October 1990 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference FHB/1 Draft for comment 86/14291 DC ISBN 0 580 18927 9 Committees responsible for this British Standard The preparatio
3、n of this British Standard was entrusted by the Farm and Horticultural Buildings Standards Policy Committee (FHB/-) to Technical Committee FHB/1, upon which the following bodies were represented: AFRC Institute of Engineering Research Aggregate Concrete Block Association Brick Development Associatio
4、n British Cement Association British Commercial Glasshouse Manufacturers Association British Constructional Steelwork Association Ltd. British Poultry Federation Limited British Precast Concrete Federation Ltd. British Veterinary Association British Wood Preserving Association British Woodworking Fe
5、deration Cold Rolled Sections Association Department of Agriculture and Fisheries for Scotland Department of Agriculture Northern Ireland Electricity Supply Industry in England and Wales Farm and Rural Buildings Centre Farm Buildings Association Fibre Cement Manufacturers Association Limited Health
6、and Safety Executive Institution of Civil Engineers Local Authority Organizations Ministry of Agriculture, Fisheries and Food National Farmers Union Royal Institute of British Architects Royal Institution of Chartered Surveyors Steel Construction Institute Timber Research and Development Association
7、 Amendments issued since publication Amd. No. Date Comments 9086 March 1996 Indicated by a sideline in the marginBS5502-32:1990 BSI 09-1999 i Contents Page Committees responsible Inside front cover Foreword ii 0 Introduction 1 1 Scope 1 2 Definitions 1 3 General 1 4 Effect of noise on humans 1 5 Eff
8、ect of noise on livestock 2 6 Sources of noise 3 7 Controlling noise 3 Annex A Bibliography 5 Index 7 Table 1 Noise levels and maximum duration of daily exposure (employedpersons) 2 Table 2 Examples of noise levels of various agricultural activities 3 Publication(s) referred to Inside back coverBS55
9、02-32:1990 ii BSI 09-1999 Foreword This Part of BS 5502 has been prepared under the direction of the Farm and Horticultural Buildings Standards Policy Committee and comprises a new Part of BS5502. While BS 5502 is being revised and added to, the opportunity is being taken to restructure the standard
10、 into the following broad subject areas: Part 0: Introduction and consolidated index 1) ; Parts 10 to 19: Reference information and legislation; Parts 20 to 39: General design; Parts 40 to 59: Livestock buildings; Parts 60 to 79: Crop buildings; Parts 80 to 99: Ancillary buildings. More specifically
11、, the general design series will comprise: Part 20: Code of practice for general design considerations; Part 21: Code of practice for selection and use of construction materials; Part 22: Code of practice for design, construction and loading; Part 23: Code of practice for fire precautions; Part 24:
12、Code of practice for energy management; Part 25: Code of practice for design and installation of services and facilities; Part 30: Code of practice for control of infestation; Part 31: Guide to waste management; Part 32: Guide to noise attenuation; Part 33: Guide to control of odour pollution; Part
13、34: Guide to control of dust; Part 35: Guide to control of gases and vapours. A more detailed description of the new structure of BS5502 is given in Part 0 1) . The object of introducing the new structure is to allow subject areas to be broadly characterized, and related subject matter, whether in t
14、he form of recommendations, guidance or supporting data to be rationalized and brought together. It will also allow sufficient flexibility to enable BS 5502 to be expanded and developed in a logical way in the future. Parts20 to39 relating to general design will broadly follow the existing structure
15、 of BS5502-1.0 to 1.7. It has been assumed in the drafting of this British Standard that the execution of its provisions is entrusted to appropriately qualified and experienced people, for whose guidance it has been prepared. A British Standard does not purport to include all the necessary provision
16、s of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 8, an insi
17、de back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In preparationBS5502-32:1990 BSI 09-1999 1 0 Introduction This Part of BS 5502 identifies those op
18、erations which occur during the normal use of agricultural buildings and structures, and give rise to noise pollution and which can be mitigated against by good design in the building and structure. To some extent the effects of pollution are subjective and depend upon the related environment. The a
19、im of the guidance given in this Part of BS 5502 is to indicate to the designer ways in which the effects of pollution can be reduced by the effective design and construction of a building and structure. In doing so, the assumption is made that use of the building will follow established agricultura
20、l practice and that equipment and machinery installed and/or used is of itself effective in minimizing pollution effects. 1 Scope This Part of BS 5502 gives guidance on aspects of controlling noise pollution in relation to the design and construction of agricultural buildings and structures. This Pa
21、rt does not cover the design of specific equipment installed and used in agricultural buildings. It does not cover vehicle noise. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard, the definiti
22、ons given in BS6100 apply. NOTEWork has commenced on a further Part of BS5502 (Part10) which will be a glossary of terms for buildings and structures for agriculture. 3 General Noise is commonly described as “any audible sound” and sound is a physical phenomenon caused by small rapid fluctuations in
23、 air pressure arising from a vibrating body. These cyclic movements are transmitted through the air and recognized by the ear as sound. A principal characteristic of sound is the frequency at which the vibrations occur, denoted Hertz (Hz), formerly cycles per second (c/s). The human ear is most sens
24、itive at1000Hz to3000Hz whilst studies indicate that auditory sensitivity of cattle is greatest at8000Hz and that of sheep at7000Hz. It is unusual to experience sounds operating solely at one frequency as most sounds comprise a variety of different frequencies. An equally important characteristic is
25、 the sound pressure level. This is measured on a logarithmic scale against a reference level taken as the threshold of audibility and scaled in decibels (dB). Since decibels are logarithmic units they cannot simply be added together and combining two levels each of60dB gives a resultant level of63dB
26、. This means that doubling the sound energy gives only a3dB increase. This difference is scarcely noticed by most observers and a difference of10dB would be judged subjectively as twice as loud. The range of audibility is generally considered to be 0dB to 120dB. Above120dB the sensation is likely to
27、 be painful. Instruments are available which measure both the sound pressure level and frequency of noise. Most instruments measure noise on a frequency weighted scale which corresponds approximately to the performance of the ear. Such measurements are termed A weighted or dB(A). It is important tha
28、t this distinction is observed to avoid errors in interpretation of reading. 4 Effect of noise on humans 4.1 Hearing loss Noise induced deafness occurs due to exposure to high noise levels. As the degree of deafness is related to the total energy received by the ear an assessment of a likely hearing
29、 hazard should include the following: a) the period of exposure to noise; b) the actual noise levels. As recommended by the code of practice for reducing the exposure of employed persons to noise (seeA.11), daily exposures to noise should not exceed90dB(A) over an8h period. Where noise levels are fa
30、irly steady and exposure is continuous, an assessment of the likely hearing hazard is fairly straightforward. In conditions where the noise levels are highly variable and/or exposure is intermittent, an equivalent continuous sound level (LAeq) should be calculated to determine whether exposure over
31、an8h period exceeds90dB(A). This should be assessed either by using an integrating sound level meter or by one of the alternative methods of assessment given in the code of practice for reducing the exposure of employed persons to noise (seeA.11). The likely damage to hearing is energy-related and t
32、he relationship between noise level and exposure time is given inTable 1.BS5502-32:1990 2 BSI 09-1999 It is essential that the unprotected ear should not, under any circumstances, be exposed to sound pressure levels exceeding135dB(A) measured with an instrument set to the fast response or in the cas
33、e of impulse noise to an instantaneous sound pressure exceeding150dB(A). The use of ear protection offers an interim solution until a more permanent solution is found. There is however continual uncertainty as to whether personal protective equipment will actually be worn and whether, if worn, it wi
34、ll provide adequate protection for a particular noise level. The use of ear plugs and ear muffs by operators may give a reduction of 5 dB(A) to 10 dB(A) and 10 dB(A) to 20 dB(A) respectively in noise levels, but this may not always prove to be so. Maintenance of the equipment and training of the per
35、sonnel in its use is essential. NOTEAdvice on the selection, use, care and maintenance of hearing protectors is given in the code of practice for reducing the exposure of employed persons to noise (seeA.11). The Noise at Work Regulations1989 are relevant. They implement a European Directive on the p
36、rotection of workers from the risks related to exposure to noise at work. Amongst other things the Regulations require employers to make noise assessments and reduce the risk of damage to hearing from noise exposure, where necessary. 4.2 Effect of noise on neighbours The intrusive nature of noise ar
37、ises from its level over background noise and in particular its tonal (frequency) characteristics and intermittency. A method for rating various noises of industrial origin is described in BS4142 together with a set of corrections covering a commonly occurring range of environmental conditions in or
38、der to predict whether the noise in question is likely to give rise to complaints. NOTEThe method described in BS4142 is intended for rating outdoor measurements and not for noise measured inside a building or arising within a building. 4.3 Communication To understand the spoken word, persons are de
39、pendent on the intensity and frequency of background noise. A background noise level of75dB(A) to 85dB(A) will usually be accepted for face to face talking in process areas whilst, for control rooms, a comfortable level is 55 dB(A) to65dB(A). BS 4142 suggests, when no measurement is possible, a back
40、ground noise of 50 dB(A) which may be corrected for various factors. The actual level of noise in rural areas is likely to be lower. Studies have found measured background noise levels to be as low as 25 dB(A) to 30 dB(A) at night. The prolonged use of machinery such as crop drying equipment in oper
41、ation for periods of time, and in wet seasons for many days or weeks, is likely to give rise to complaints in residential rural areas. Table 1 Noise levels and maximum duration of daily exposure (employed persons) 5 Effect of noise on livestock Sudden loud sounds such as that produced from thunder 1
42、20 dB(A) are particularly stressful and frightening to animals. Studies have shown that sheep exposed to 75 dB(A) gained weight faster than those exposed to 100 dB(A). Nevertheless sheep exposed to instrumental music had significantly lower heart beats than those exposed to white noise (a static his
43、s) or miscellaneous sounds such as trains and fog horns. Noisy equipment should not be sited in areas where animals need to walk in file. Air equipment should be checked for leaks and fitted with mufflers. Gates should either be counterweighted so that they close gently after the animals or be fitte
44、d with rubber or timber padding to prevent the noise of metal hitting metal. In the absence of any quantitative levels with regard to the effect of noise on animals it is recommended that the maximum duration of daily exposure should be8h per day at90dB(A). Noise level Maximum duration of daily expo
45、sure dB(A) per day 90 91 92 93 94 95 96 99 102 108 115 8 h 6 h 5 h 4 h 3 h 2.5 h 2 h 1 h 30 min 7.5 min 1.5 minBS5502-32:1990 BSI 09-1999 3 6 Sources of noise Sources of noise often emanate from equipment such as crop dryers and ventilation plant, from activities such as seed cleaning, crushing and
46、milling or from animals such as pigs at feeding time. Some typical ranges of noise levels are given inTable 2. When selecting equipment consideration should be given to the prevention of excessive noise production at source so as to achieve a noise level as low as possible without interfering with t
47、he optimum performance of the machine. Equipment should also be kept clean and regularly maintained to avoid poor performance and increase in noise. Attention should be given to minor details likely to be an irritating nuisance, e.g. loose covers, loose guards or loose chain cases. 7 Controlling noi
48、se 7.1 General Noise control measures are well known in principle, but may be difficult to apply in farmstead situations. The most effective way of reducing noise is to reduce noise levels at their source. NOTE 1BS 8233 incorporates the results of research and experience gained over two decades and
49、provides up to date recommendations on the control of noise in and around buildings. NOTE 2Further information with regard to the screening of noisy processes or adding mass to buildings to reduce airborne noise may be found in CIRIA Report 114 (seeA.6). This is written for houses and flats, but the principles may be applied to agricultural structures. Table 2 Examples of noise levels of various agricultural activities 7.2 Siting 7.2.1 Noise levels reduce as the distance from the source increases. This reduction can for practical p
