DIN EN ISO 15927-3-2009 Hygrothermal performance of buildings - Calculation and presentation of climatic data - Part 3 Calculation of a driving rain index for vertical surfaces fro.pdf

1、August 2009DEUTSCHE NORM English price group 12No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 91.060.10; 91.120.10; 9

2、1.120.30!$Y90“1542213www.din.deDDIN EN ISO 15927-3Hygrothermal performance of buildings Calculation and presentation of climatic data Part 3: Calculation of a driving rain index for vertical surfaces fromhourly wind and rain data (ISO 15927-3:2009)English version of DIN EN ISO 15927-3:2009-08Wrme- u

3、nd feuchteschutztechnisches Verhalten von Gebuden Berechnung und Darstellung von Klimadaten Teil 3: Berechnung des Schlagregenindexes fr senkrechte Oberflchen aus stndlichenWind- und Regendaten (ISO 15927-3:2009)Englische Fassung DIN EN ISO 15927-3:2009-08www.beuth.deDocument comprises 23 pagesDIN E

4、N ISO 15927-3:2009-08 2 National foreword This standard has been prepared by Technical Committee CEN/TC 89 “Thermal performance of buildings and building components” (Secretariat: SIS, Sweden) in collaboration with Technical Committee ISO/TC 163 “Thermal performance and energy use in the built envir

5、onment”. The responsible German body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Technical Committee NA 005-56-99 AA Feuchte. Technical Committee CEN/TC 89 and Technical Committee ISO/TC 163 agreed to incorporate the European Dra

6、ft Standard prEN 13013-3, Hydrothermal performance of buildings Climatic data Part 3: Calculation of a driving rain index for vertical surfaces from hourly wind and rain data in EN ISO 15927-3:2009. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 15927-3 March 2009 ICS 91.120.10; 07.060 Eng

7、lish Version Hygrothermal performance of buildings - Calculation and presentation of climatic data - Part 3: Calculation of a driving rain index for vertical surfaces from hourly wind and rain data (ISO 15927-3:2009) Performance hygrothermique des btiments - Calcul et prsentation des donnes climatiq

8、ues - Partie 3: Calcul dun indice de pluie battante pour surfaces verticales partir de donnes horaires de vent et de pluie (ISO 15927-3:2009) Wrme- und feuchteschutztechnisches Verhalten von Gebuden - Berechnung und Darstellung von Klimadaten - Teil 3: Berechnung des Schlagregenindexes fr senkrechte

9、 Oberflchen aus stndlichen Wind- und Regendaten (ISO 15927-3:2009) This European Standard was approved by CEN on 31 January 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standa

10、rd without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other l

11、anguage made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Fi

12、nland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES

13、 KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 15927-3:2009: EContents Page 2 EN ISO 15927-3:2009 (E) DIN EN ISO 15927-3:2009-08 Foreword .3 Introdu

14、ction.4 1 Scope5 2 Terms, definitions, symbols and units6 3 Calculation of airfield indices from hourly wind and rain data 8 4 Estimation of the effect of driving rain from average wind and present weather code for rain 8 5 Calculation of wall indices .9 Annex A (informative) Limits to the validity

15、of the calculated indices15 Annex B (informative) The nature of a “spell” of driving rain16 Annex C (informative) The procedure for generating the driving-rain maps17 Annex D (informative) Comparison of methods specified in Clauses 3 and 4 .19 Bibliography21 Foreword 3 This document (EN ISO 15927-3:

16、2009) has been prepared by Technical Committee ISO/TC 163 “Thermal performance and energy use in the built environment“ in collaboration with Technical Committee CEN/TC 89 “Thermal performance of buildings and building components”, the secretariat of which is held by SIS. This European Standard shal

17、l be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2009, and conflicting national standards shall be withdrawn at the latest by September 2009. Attention is drawn to the possibility that some of the elements of this

18、document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standa

19、rd: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. E

20、N ISO 15927-3:2009 (E) DIN EN ISO 15927-3:2009-08 Introduction This part of ISO 15927 specifies two procedures for analysing data derived from hourly observations of wind and rainfall so as to provide an estimate in terms of both an annual average and short-term spells of the quantity of water likel

21、y to impact on a wall of any given orientation. The first method, which uses hourly observations of wind and rainfall, is based closely on BS 81041, which originated from a long series of measurements of driving rain on buildings in a wide range of locations within the UK. As such, the method applie

22、s to climates similar to those in the UK; in other regions, with very different climates, it is recommended that confirmation of its applicability be obtained by measurements of driving rain on representative buildings. Where hourly observations of wind and rain are not available, the second procedu

23、re, based on the present weather code for rain and average wind speeds can be used. In all cases, especially in mountainous areas, it is important that direct measurements of the rain impacting on building faades be made wherever possible. Rain penetration around the edges of doors and windows or si

24、milar cracks in building faades depends on shorter periods of heavy rain and strong winds. 4 EN ISO 15927-3:2009 (E) DIN EN ISO 15927-3:2009-08 1 Scope This part of ISO 15927 specifies two procedures for providing an estimate of the quantity of water likely to impact on a wall of any given orientati

25、on. It takes account of topography, local sheltering and the type of building and wall. The first method, given in Clause 3 and based on coincident hourly rainfall and wind data, defines a means of calculating the annual average index, which influences the moisture content of an absorbent surface, s

26、uch as masonry, and the spell index, which influences the likelihood of rain penetration through masonry and joints in other walling systems. The second method, given in Clause 4 and based on average wind data and a qualitative recording of the presence and intensity of rain (the present weather cod

27、e for rain), defines a means of calculating the spell length during which an absorbent material such as masonry is moistened, which has a 10 % probability of being exceeded in any year (commonly referred to as having a mean return period of 10 years). A comparison between the two methods is given in

28、 informative Annex D. Procedures are given to correct the results of both methods for topography, local sheltering and the type of building and wall. The methods included in this part of ISO 15927 do not apply in a) mountainous areas with sheer cliffs or deep gorges, b) areas in which more than 25 %

29、 of the annual rainfall comes from severe convective storms, c) areas and periods when a significant proportion of precipitation is made up of snow or hail. 5 EN ISO 15927-3:2009 (E) DIN EN ISO 15927-3:2009-08 2 Terms, definitions, symbols and units For the purposes of this document, the following t

30、erms, definitions, symbols and units apply. 2.1 Definitions 2.1.1 spell period, or sequence of periods, of wind-driven rain on a vertical surface of given orientation NOTE Further information about spells is given in Annex B. 2.1.2 airfield hourly index quantity of driving rain that would occur on a

31、 vertical wall of given orientation per square metre of wall during 1 h at a height of 10 m above ground level in the middle of an airfield, at the geographical location of the wall 2.1.3 airfield annual index airfield index for a given wall orientation totalled over one year 2.1.4 airfield spell in

32、dex airfield index for a given wall orientation totalled over the worst spell likely to occur in any three-year period 2.1.5 wall annual index quantity of wind-driven rain per square metre at a point on a wall of given orientation, based on the airfield annual index and corrections for roughness, to

33、pography, obstruction and wall factors 2.1.6 wall spell index quantity of wind-driven rain per square metre at a point on a given wall, based on the airfield spell index and corrections for roughness, topography, obstruction and wall factors 2.1.7 line of sight horizontal view away from the wall, ov

34、er a sector spanning about 25 either side of the normal to the wall 2.1.8 terrain roughness category classification of the surface roughness upwind in terms of the average height and spacing of obstructions such as buildings, trees or hedges 2.1.9 roughness coefficient factor that allows for the mod

35、ification of the wind speed by the roughness of the terrain upwind of a wall 2.1.10 topography coefficient factor that allows for the effect of local topography on the wind speed 2.1.11 obstruction factor factor that relates to shelter from the very local environment and allows for obstructions such

36、 as buildings, fences and trees close to, and upwind of, the wall 2.1.12 wall factor ratio of the quantity of water hitting a wall to the quantity passing through an equivalent unobstructed space, allowing for the characteristics of the wall 6 EN ISO 15927-3:2009 (E) DIN EN ISO 15927-3:2009-08 2.1.1

37、3 wall orientation angle between north and line normal to a wall 2.1.14 convective storm heavy precipitation in the form of showers or thunderstorms generally lasting less than 1 h 2.1.15 reference spell period during which a wall oriented in any given direction is moistened, having a 10 % probabili

38、ty of being exceeded in any year 2.1.16 present weather code numerical code used by meteorological observers to assess the weather conditions at the time of an observation NOTE Present weather codes are given in the WMO Guide2. 2.1.17 half day twelve-hour period including the hours from 07:00 to 18:

39、00 or from 19:00 to 06:00 2.2 Symbols and units Symbol Quantity Unit CRroughness coefficient CTtopography coefficient D hourly mean wind direction from north H effective height of feature m IAairfield annual index l/m2ISairfield spell index l/m2IWAwall annual index l/m2IWSwall spell index l/m2KRterr

40、ain factor L length mN number of years of available data O obstruction factor r hourly rainfall total mm v hourly mean wind speed m/s W wall factor x horizontal distance m z height above ground m z0roughness length m zminminimum height m wall orientation relative to north 7 EN ISO 15927-3:2009 (E) D

41、IN EN ISO 15927-3:2009-08 3 Calculation of airfield indices from hourly wind and rain data 3.1 Sources of data Data used for calculations according to this part of ISO 15927 shall have been measured by the methods specified by the World Meteorological Organization (see WMO Guide2). 3.2 Airfield annu

42、al index For any location with at least 10 (and preferably 20 or 30) years of hourly values of wind speed, wind direction and rainfall, the annual index for wall orientation, , is given by Equation (1). vr D IN=89Acos( )29(1) where the summation is taken over all hours for which cos(D ) is positive,

43、 i.e. all those occasions when the wind is blowing against the wall. As the wind speed during rainfall is not generally the same as in dry weather, calculating the product of hourly averages of wind and rainfall is not strictly accurate, especially in showery weather. It has been shown, however, tha

44、t the error is small and, in any case, several years of data for periods shorter than 1 h are available from very few places. Taking the product of the averages over days or months does lead to serious inaccuracies and should not be used for calculating driving rain indices. 3.3 Airfield spell index

45、 For any location with at least 10 (and preferably 20 or 30) years of hourly values of wind speed, wind direction and rainfall, for each wall orientation, , and for each spell of driving rain (see Annex B), calculate SI using Equation (2). ()IvrD =89S2cos9(2) where the summation is taken over all ho

46、urs in the spell for which cos(D ) is positive, i.e. all those occasions when the wind is blowing against the wall. The 67 %percentile (i.e. the value for which 33 % of the SI values are higher) is found from the values of SI for all the spells within the period of available data. The 67 % percentil

47、e defines the spell index, IS(i.e. the maximum value of SI likely to occur once every three years). 4 Estimation of the effect of driving rain from average wind and present weather code for rain The available data are divided into twelve-hour periods (07:00 18:00 and 19:00 06:00) called half days. A

48、 half day is defined as “moistening” if all of the following conditions apply. a) There is more than 4 mm of precipitation on a horizontal surface in the half day. b) The present weather code reports some precipitation for at least three of the five three-hourly observations during the half day (i.e

49、. at 06:00, 09:00, 12:00, 15:00 and 18:00 and at 18:00, 21:00, 00:00, 03:00 and 06:00). NOTE Present weather codes of 50 or above indicate some form of precipitation. 8 EN ISO 15927-3:2009 (E) DIN EN ISO 15927-3:2009-08 c) The average wind speed during the half day is greater than 2 m/s. d) The average wind direction during the half day is within 60 of the perpendicular to the wall, i.e. 60D u . Under these conditions, it is assumed that a wall surface will be wetted by driving rain, with subseque