1、BRITISH STANDARD BS 7643-1: 1993 ISO 6242-1: 1992 Building construction Expression of users requirements Part 1: Thermal requirements UDC 69.004.2-533:697:644.1BS7643-1:1993 This British Standard, having been prepared under the directionof the Technical Sector Board for Building and Civil Engineerin
2、g, was published underthe authority ofthe Standards Board and comes into effect on 15March1993 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference B/500 Draft for comment 89/16526 DC ISBN 0 580 21641 1 Committees responsible for this British Standard The
3、 preparation of this British Standard was entrusted by the Technical Sector Board for Building and Civil Engineering (B/-) to Technical CommitteeB/500, upon which the following bodies were represented: Building Employers Confederation Consumer Policy Committee of BSI Convention of Scottish Local Aut
4、horities Department of Education and Science Department of the Environment Department of the Environment (Building Research Establishment) Incorporated Association of Architects and Surveyors Meteorological Office National Building Specification Ltd. National Council of Building Material Producers N
5、ational House-Building Council Royal Institute of British Architects Society of Chief Architects of Local Authorities Amendments issued since publication Amd. No. Date CommentsBS7643-1:1993 BSI 08-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Sc
6、ope 1 2 Users objectives 1 3 Parameters for expressing users requirements 1 4 Factors affecting the choice of criteria 2 Annex A (informative) Bibliography Inside back cover Table 1 Parameters 3 Table 2 Factors affecting criteria 4BS7643-1:1993 ii BSI 08-1999 National foreword This Part of BS7643 ha
7、s been prepared under the direction of Technical CommitteeB/500, Basic data, and is identical with ISO6242-1:1992 Building construction Expression of users requirements Part 1: Thermal requirements, published by the International Organization for Standardization (ISO). ISO 6242-1 was prepared by Sub
8、committee3, Functional/user requirements and performance in building construction, with the active participation and approval of the United Kingdom. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct
9、 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 4, an inside back cover and a back cover. This standard has been updated (see copyright
10、 date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS7643-1:1993 BSI 08-1999 1 Introduction This part of ISO6242 is one of a set dealing with the expression of environmental requirements for buildings, in terms suitable for use in
11、 regulations and briefs for building projects. The parameters defined can be used for routine verification of the performance of buildings, either by calculation (for example at the design stage) or measurement (for example of spaces or whole buildings), and are meant to provide readily understood i
12、nformation on users requirements throughout the building process. This set of International Standards is not intended to represent the complete state of knowledge about these aspects of environmental science, some of which are the concern of other ISO Technical Committees. 1 Scope This part of ISO 6
13、242 defines how the thermal requirements of building users can be identified, expressed and quantified. It describes users objectives and the parameters used to express them. For each parameter, it specifies units of measurement, preferred increments for values and means of evaluation. It also lists
14、 the environmental and human factors affecting the choice of a value (criterion) for each parameter. It is intended for use a) in preparing briefs for building projects; b) in formulating building laws and regulations; c) in drafting standards and other normative documents; and d) more generally whe
15、n specifying the required performance of buildings in terms of users requirements. Some of the parameters given in this part of ISO6242 apply only to certain types of building. Compliance with this part of ISO6242 does not therefore depend on implementing the whole of its contents in every case. 2 U
16、sers objectives 2.1 Control of the thermal environment within buildings shall fulfil the following objectives: a) to provide conditions which will prevent occupants suffering from heat stress or cold stress; and b) to provide a suitable standard of thermal comfort for occupants. 2.2 Criteria meeting
17、 these objectives shall reflect the following: a) activities to be accommodated; b) clothing; c) age and health of the occupants; d) proportion of likely occupants it is intended to satisfy; e) time during which the requirements must be satisfied (taking account of climatic extremes); and f) any fac
18、ility for local control of the thermal environment by the occupants. The choice of parameters and criteria will differ, depending on the type of climate in which the building is placed. 3 Parameters for expressing users requirements Thermal comfort and freedom from thermal stress depend on the follo
19、wing environmental factors: a) air temperature; b) radiation gains and losses; c) air humidity; d) air velocity; e) metabolic rate; and f) clothing. Requirements can be defined separately for each of these factors, although, because their physiological effects are interdependent, it may be necessary
20、 to give several, cross-related requirements for different ranges of bands of values. It is often convenient to integrate several of the factors into a combined index, such as resultant temperature or operative temperature. In view of the inevitable variation in the thermal environment over space an
21、d time, it is vital that statements of users requirements should not only include limiting values but should also define locations and tolerances for the values: as this kind of information is common to several of the parameters, its expression is given first in3.1. 3.1 Location, uniformity and tole
22、rance for thermal parameters For most spaces within buildings, specified temperatures should apply on a plane1m above finished floor level. On this plane, under continuous operating conditions, the required values (set separately for winter and summer, where applicable) should be met to within a tol
23、erance of 1,5 C, excluding the effects of solar radiation through windows or roof-lights. In certain cases, for example auditoria, it may be necessary to define other planes covering all or part of the space.BS7643-1:1993 2 BSI 08-1999 The maximum temperature gradient in the vertical plane will need
24、 to be specified. For most rooms or spaces of normal height (not exceeding3m) the temperature should not vary by more than3 C. Where heating is intermittent, or where night set-back or other periods of reduced heat input are employed, it may be necessary to specify a) wider tolerance limits within t
25、he first and last hours of use or occupancy; b) supplementary specified temperatures for periods of zero or reduced heat input. 3.2 Expression of thermal parameters Details of means of expression, together with associated information, are given inTable 1. 4 Factors affecting the choice of criteria D
26、etails of factors likely to affect the choice of criteria for particular applications, together with associated information, are given inTable 2.BS7643-1:1993 BSI 08-1999 3 Table 1 Parameters Parameter Definition Means of expression: units; preferred increments Nature of criterion Means of evaluatio
27、n Dry-bulb air temperature (t a ) The temperature of the air indicated by a thermometer shielded from radiation a Degrees Celsius ( C); whole C Maximum and/or minimum Calculation: in accordance with national standards or codes of practice on thermal design Measurement: using any method of static or
28、dynamic (aspirated) temperature measurement capable of accurately measuring the average dry-bulb temperature of the air in a room, space or zone Mean radiant temperature () The uniform surface temperature of a radiantly black enclosure in which the occupant would exchange the same amount of radiant
29、energy as in the actual non-uniform space b Degrees Celsius ( C); whole C Maximum and/or minimum Calculation: as the resulting effect of the integral, at a particular point, of incident radiant fluxes to and from all directions, including gains from and losses to windows and roof-lights Measurement:
30、 not directly measurable Air velocity ( a ) The velocity of the air, when sufficient in volume and duration to affect thermal comfort Metres per second (m/s) Maximum and/or minimum Calculation: in accordance with national standards or codes of practice on thermal design Measurement: using any method
31、 capable of accurately measuring air velocity with an averaging time of 1 s to 2 s, and of distinguishing the direction of air movement Operative temperature (t o ) The uniform temperature of a radiantly black enclosure in which the occupant would exchange the same amount of heat by radiation plus c
32、onvection as in the actual non-uniform environment b Degrees Celsius ( C); whole C Maximum and/or minimum Calculation: it is normally sufficient to compute the operative temperature as For higher precision the following expression should be used: where A depends on air velocity, as follows: a 0,2 0,
33、2 to 0,6 0,6 to 1 A 0,5 0,6 0,7 Wet-bulb air temperature (t nw ) The temperature indicated by a sensing element kept wet as a measure of the rate of evaporation Degrees Celsius ( C); whole C Maximum and/or minimum Calculation: in accordance with national standards or codes of practice on thermal des
34、ign Measurement: using a wet-bulb thermometer or other instrument giving equivalent measurements a From BLIGH J. and JOHNSON K.G. Glossary of terms for thermal physiology. Journal of Applied Physiology, 35 (6), December1973. b From ANSI/ASHRAE 55:1981, Thermal environmental conditions for human occu
35、pancy. t r t o t a t r + 2 - = t o At a 1 A ()t r + =BS7643-1:1993 4 BSI 08-1999 Table 2 Factors affecting criteria Factor Examples of classes/categories Means of expression Sources of information Activities and tasks in relation to the thermal comfort Reclining Sedentary Standing Light activity Med
36、iumactivity Heavyactivity Metabolic rate of human body (based on standard data relating to average, healthy adults), expressed either in W/m 2or met aunits ISO 7730:1984, Annex B ANSI/ASHRAE 55:1981, Table 3 ISO 8996:1990 Clothing Underwear Tropicalwear Summerwear Winterwear Insulation value of clot
37、hing, expressed either in m 2 C/W or clo b ISO 7730:1984, Annex C ANSI/ASHRAE 55:1981, table Age and health Children Healthyadults Disabled adults Medical patients Elderly Alternative or supplementary values for metabolic rate, related to activities Proportion of occupants to be satisfied 80 % 90 %
38、95 % Predicted Percentage of Dissatisfied (PPD), expressed in terms of Predicted Mean Vote (PMV) ISO 7730:1984, clauses 3 and 5 Time during which requirements must be satisfied 90 % 95 % 99 % Usually governed by the choice of climatic extremes used for the design of heating or air-conditioning syste
39、ms, which will have a specific chance of being exceeded. Also influenced by factors such as over-capacity of such systems, and the uniformity of their performance in providing thermal comfort in different parts of a building a 1 met = 58 W/m 2 b 1 clo = 0,16 m 2 C/WBS7643-1:1993 BSI 08-1999 Annex A
40、(informative) Bibliography 1 ISO 6240:1980, Performance standards building Contents and presentation. 2 ISO 6241:1984, Performance standards in buildingPrinciples for their preparation and factors to be considered. 3 ISO 7162:1992, Performance standards in building Contents and format of standards f
41、or evaluation of performance. 4 ISO 7164-1:, Performance standards in building Part1: Definitions and means of expression for the performance of a whole building 1) . 5 ISO 7243:1989, Hot environments Estimation of the heat stress on working man, based on the WBGT-index (wet bulb globe temperature).
42、 6 ISO 7726:1985, Thermal environments Instruments and methods for measuring physical quantities. 7 ISO 7730:1984, Moderate thermal environments Determination of the PMV and PPD indices and specification of the conditions for thermal comfort. 8 ISO 7933:1989, Hot environments Analytical determinatio
43、n and interpretation of thermal stress using calculation of required sweat rate. 9 ISO 8996:1990, Ergonomics Determination of metabolic heat production. 10 ANSI/ASHRAE 55:1981, Thermal environmental conditions for human occupancy. 1) To be published.BS 7643-1: 1993 ISO 6242-1: 1992 BSI 389 Chiswick
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