SIST EN 1745:2004
(Main)Masonry and masonry products - Methods for determining design thermal values
Masonry and masonry products - Methods for determining design thermal values
This European Standard gives procedures for the determination of design thermal values (thermal resistance and/or thermal conductivity) of masonry and masonry products.
Mauerwerk und Mauerwerksprodukte - Verfahren zur Ermittlung von Wärmeschutzrechenwerten
Diese Europäische Norm beschreibt Verfahren zur Ermittlung von Wärmeschutzrechenwerten (Wärme-
durchlasswiderstand und/oder Wärmeleitfähigkeit) für Mauerwerk und Mauerwerksprodukte sowie Ver-
fahren für die Erstprüfung und die Eigenüberwachung von Wärmedämmeigenschaften.
Maçonnerie et éléments de maçonnerie - Détermination des valeurs thermiques de calcul
La présente norme européenne fournit des procédures de détermination des valeurs thermiques de calcul (résistance thermique et/ou conductivité thermique) de la maçonnerie et des éléments de maçonnerie.
Zidovje in zidarski proizvodi – Metode za določanje projektnih (računskih) toplotnih lastnosti
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.DþXQVNLKMauerwerk und Mauerwerksprodukte - Verfahren zur Ermittlungvon WärmeschutzrechenwertenMaçonnerie et éléments de maçonnerie - Détermination des valeurs thermiques de calculMasonry and masonry products - Methods for determining design thermal values91.120.10Toplotna izolacija stavbThermal insulation91.080.30Zidane konstrukcijeMasonryICS:Ta slovenski standard je istoveten z:EN 1745:2002SIST EN 1745:2004en01-januar-2004SIST EN 1745:2004SLOVENSKI
STANDARD
SIST EN 1745:2004
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1745April 2002ICS 91.080.30; 91.120.10English versionMasonry and masonry products - Methods for determiningdesign thermal valuesMaçonnerie et éléments de maçonnerie - Déterminationdes valeurs thermiques de calculMauerwerk und Mauerwerksprodukte - Verfahren zurErmittlung von WärmeschutzrechenwertenThis European Standard was approved by CEN on 15 September 2000.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1745:2002 ESIST EN 1745:2004
EN 1745:2002 (E)2Contentspage1Scope.62Normative references.63Definitions and symbols.73.1Definitions.73.2Symbols.84Procedures to determine design thermal values for solid masonry units andmortars.84.1General.84.2Basic -values for solid masonry units and mortars.94.2.1Tabulated -values (determination based on -density relation only).94.2.2Measured -values (determination based on -density relation and initial typetesting of ).94.3Design RU- or U-values for solid masonry units and mortars.115Procedures to determine design thermal values (RU or equivalent U) of masonrybuilt from solid masonry units and mortar.125.1Test measurements.125.2Calculation methods.125.2.1General.125.2.2Numerical calculation.135.2.3Simplified calculation.136Procedures to determine design thermal values (RU or equivalent U) for masonryunits with formed voids and composite masonry units and for walls built fromsuch units and mortar.136.1General.136.2RU- or equivalent U-values of masonry units with formed voids and compositemasonry units.136.3RU- or equivalent U-values of masonry built from masonry units with formedvoids or composite masonry units and mortar.136.3.1Tabulated values.136.3.2Test measurements.156.3.3Calculation methods.167Determination of the thermal transmittance of masonry.16Annex A (normative)
Tabulated 10,dry-values of materials used for masonry products andmortar products.17Annex B (informative)
Tabulated basic R- or equivalent -values of masonry built frommasonry units with formed voids.27Annex C (informative)
Example how to use the table in annex B.51Annex D (normative)
Requirements for appropriate calculation procedures.52D.1Capabilities of the program.52D.2Input data and results.52D.3Testing of the program accuracy.53D.4Reference cases.53Annex E (normative)
Evaluation of conformity of -or R-values.61E.1General.61SIST EN 1745:2004
EN 1745:2002 (E)3E.2Initial thermal type-testing of a product.61E.3Factory production control.61E.3.1Control of finished products — based on tabulated values.61E.3.2Control of finished products — based on measurements.61Annex ZA
(informative)
A-deviations.63Bibliography.65SIST EN 1745:2004
EN 1745:2002 (E)4ForewordThis document (EN 1745:2002) has been prepared by Technical Committee CEN/TC 125 "Masonry",the secretariat of which is held by BSI.This European Standard shall be given the status of a national standard, either by publication of anidentical text or by endorsement, at the latest by October 2002, and conflicting national standardsshall be withdrawn at the latest by October 2002.This European Standard has been prepared under a mandate given to CEN by the EuropeanCommission and the European Free Trade Association, and supports essential requirements of EUDirective(s).The annexes A, D and E are normative. The annexes B and C are informative.The following clauses in this Standard are the subject of an A-deviation resulting from a request byFrance:4.1, 4.2.1, 4.2.2.4, 4.3, 5.1, 5.2.1, 6.2 and 6.3.1.2.Further details on the A-deviation are given in annex ZA (informative).According to the CEN/CENELEC Internal Regulations, the national standards organizations of thefollowing countries are bound to implement this European Standard : Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta,Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.SIST EN 1745:2004
EN 1745:2002 (E)5IntroductionThis standard provides rules for the determination of design values for thermal conductivity andthermal resistance of both masonry and masonry products.It also describes how the basic values for the calculation of design thermal values are determined andalso the calculation methods to derive design values from basic values. It covers solid masonry units(clauses 4 and 5) and masonry units with formed voids and composite masonry units (clause 6).Three procedures for the determination of thermal resistance and/or thermal conductivity aredescribed. These procedures are: To use tabulated lambda - and/or R-values. To measure the lambda - and/or R-value. To calculate the equivalent lambda - and/or R-value.It takes into account the major different types of masonry products: Solid masonry units. Masonry units with formed voids. Composite masonry units.The design value of a product characteristic is the value determined for specific application and foruse in calculations.Design thermal values are determined, according to the procedure given in this standard by theuser/designer and building authority according to the intended application, environmental and climaticconditions, bearing in mind the purpose of this determination, such as: energy consumption; design of heating and cooling equipment; surface temperature determination; compliance with national building codes; consideration of non steady state thermal conditions in buildings.A specific building product can have different design thermal values according to the intendedapplication. Normally the producers/distributors will supply design values for their products.SIST EN 1745:2004
EN 1745:2002 (E)61 ScopeThis European Standard gives procedures for the determination of design thermal values (thermalresistance and/or thermal conductivity) of masonry and masonry products.2 Normative referencesThis European Standard incorporates by dated or undated references, provisions from otherpublications. These normative references are cited at the appropriate places in the text and thepublications are listed hereafter. For dated references, subsequent amendments to or revisions of anyof these publications apply to this European Standard only when incorporated in it by amendment orrevision. For undated references the latest edition of the publication referred to applies (includingamendments).EN 771(all parts), Specification for masonry unitsEN 772-3, Methods of test for masonry units — Part 3: Determination of net volume and percentageof voids of clay masonry units by hydrostatic weighingEN 772-4, Methods of test for masonry units — Part 4: Determination of real and bulk density and oftotal and open porosity for natural stone masonry unitsEN 772-13, Methods of test for masonry units — Part 13: Determination of net and gross dry densityof masonry units (except for natural stone)EN 772-16, Methods of test for masonry units — Part 16: Determination of dimensionsEN 1015-10, Methods of test for mortar for masonry — Part 10: Determination of dry bulk density ofhardened mortarEN 1934, Thermal performance of buildings — Determination of thermal resistance by hot boxmethod using heat flow meter — MasonryEN ISO 6946:1996, Building components and building elements — Thermal resistance and thermaltransmittance — Calculation method (ISO 6946:1996)EN ISO 7345, Thermal insulation — Physical quantities and definitions (ISO 7345:1987)EN ISO 8990, Thermal insulation — Determination of steady-state thermal transmission properties —Calibrated and guarded hot box (ISO 8990:1994)EN ISO 10211-1, Thermal bridges in building construction — Heat flows and surface temepratures —Part 1: General calculation methods (ISO 10211-1:1995)EN ISO 10456, Building materials and products —Products for determining declared and designvalues (ISO 10456:1999)ISO 8301, Thermal insulation — Determination of steady-state thermal resistance and relatedproperties — Heat flow meter apparatusISO 8302, Thermal insulation — Determination of steady-state thermal resistance and relatedproperties — Guarded hot plate apparatusprEN 12664, Thermal performances of building materials and products — Determination of thermalresistance by means of guarded hot plate and heat flow meter methods — Dry and moist products ofmedium and low thermal resistanceSIST EN 1745:2004
EN 1745:2002 (E)73 Terms, definitions and symbolsFor the purposes of this European Standard the following terms, definitions and symbols and thosegiven in EN ISO 7345 apply.3.1 Terms and definitions3.1.1masonryassemblage of masonry units laid in a specified pattern and joined together with masonry mortar3.1.2masonry productmasonry units, masonry mortars, rendering and plastering mortars3.1.3solid masonry unitmasonry unit containing no perforations except e.g. external indentations such as gripholes, groovesetc3.1.4composite masonry unitmasonry unit made from more than one material3.1.5thermal valuecommon term for either the thermal conductivity [W/(m.K)] or the thermal resistance [m2.K/W]3.1.6basic thermal valuevalue of a thermal property of a building material or product in a dry state determined according to thisstandard as a basis for the calculation of design thermal valuesNOTEThe basic thermal value can be expressed as thermal conductivity or thermal resistance.3.1.7design thermal valuevalue of a thermal property of a building material or product under specific external and internalconditions which can be considered as typical of the performance of that material or product whenincorporated in a building componentNOTEThe design thermal value can be expressed as the thermal conductivity or thermal resistance .3.1.8equivalent thermal conductivityvalue which is derived by dividing the thickness of a given masonry unit or structure by its thermalresistance3.1.9reference conditionsset of conditions identifying a state of equilibrium selected as the base to which the thermal values ofbuilding materials and products are referred3.1.10dry statestate after drying under conventional conditions as stated in the relevant product standardsSIST EN 1745:2004
EN 1745:2002 (E)83.2 SymbolsSymbolQuantityUnit10,drythermal conductivity in dry state at an average temperature of 10 °CW/(m.K)Iindividual measured thermal conductivityW/(m.K)Udesign thermal conductivityW/(m.K)equequivalent thermal conductivityW/(m.K)RIindividual measured thermal resistancem2.K/WRUdesign thermal resistancem2.K/WTtemperatureKwater vapour diffusion coefficientcspecific heat capacitykJ/(kg.K)llength of a masonry unitmmwwidth of a masonry unitmmHU,hUheight of a masonry unitmmHM,hMthickness of a mortar jointmmFmmoisture conversion factorfumoisture conversion coefficientkg/kgfmoisture conversion coefficientm3/m3umoisture content mass by masskg/kgmoisture content volume by volumem3/m3Uthermal transmittanceW/(m2.K)Pfractile of population%4 Procedures to determine design thermal values for solid masonry unitsand mortars4.1 GeneralFor solid masonry units the -value of the material and the equivalent -value of the product areidentical.NOTEGripholes not passing through the unit are not considered as perforations.SIST EN 1745:2004
EN 1745:2002 (E)9The basic -values of solid masonry units and of mortars can be determined from tests carried out onsamples of the material or from tables or graphs which relate 10,dry to density. In both cases the-value is to be representative of the material as defined in the product standard.From these basic -values, design RU - or U -values can be calculated, taking into account the influenceof moisture.The design RU- or U-values of masonry built from solid masonry units can be determined from tables orfrom tests carried out on masonry samples or from calculations.4.2 Basic -values for solid masonry units and mortars4.2.1 Tabulated -values (determination based on -density relation only)10,dry-values for different materials used for masonry products are given in annex A, differentiated bythe type of material and the dry density of the material. This annex also contains values for the watervapour diffusion coefficient, the specific heat and the moisture coefficient, which describes theincrease of
per percent increase of moisture content.These tabulated values are valid for materials where there is production control of density but no directlymeasured -values. The values are given as 50 % and 90 % fractiles (P) of the existing range of -valuesfor a certain material for a given density.4.2.2 Measured -values (determination based on -density relation and initial type testing of)When a manufacturer decides to determine a -value from test measurement, the following procedureshall be used:4.2.2.1 Test specimensTake detailed information about test specimens from ISO 8302 and from prEN 12664.NOTECare should be taken that the test specimens are representative of the masonry product itself. Anappropriate way to ensure this, is to cut specimens from masonry units.4.2.2.2 Conditioning of specimensNormally masonry materials are tested in a dry condition. It is also possible to carry out tests in amoist condition (e.g. conditioned to constant mass in an environment of 23 °C
2 °C and 50 %
5 %relative humidity), in which case the measured value has to be converted to the dry state.4.2.2.3 Test measurementUse as the reference test method ISO 8302. More detailed information about the testing procedure formasonry materials is given in prEN 12664.Alternative test methods, such as ISO 8301, which may require different test specimens and differentconditioning methods, may be used, if the correlation between the reference test method and thealternative method can be given.4.2.2.4 The determination of the basic -valueThe determination of the basic -value is based on the mean -value and the limit -value. Threeitems of information are necessary for this determination procedure:SIST EN 1745:2004
EN 1745:2002 (E)101) The tabulated -density-correlation for the given material (see annex A).2) The product density range, which can be derived either from the production history or fromthe density tolerances which are given in the relevant product standards.3) At least three individual test measurements on density and i, which shall ensure that thebasic -value is representative for the current material produced. The three tests have to becarried out on specimens from different production batches to represent the manufacturedproduct density range. These three measurements are used to determine the distance of theindividual -density-curve, for a defined production, from the tabulated -density curve.Then use the following procedure:Calculate the arithmetic mean value of the 3 -results.Measure the density of each of the three samples in accordance with EN 772-4 or EN 772-13 orEN 1015-10 and calculate the arithmetic mean value of the 3 results.Through the point A representing mean thermal conductivity and mean density draw a /density-curveparallel to the general /density-curve obtained from plotting the tabulated - and density-values forthe product (material) given in annex A.Derive the mean -value of the product from the average density. Derive the upper and lower limitvalues as the values that represent 90 % and 10 % of the manufactured product density range with aconfidence level of 90 % according to EN ISO 10456.Express the basic -value as the mean -value together with the difference between the limit and themean value.Figure 1 shows this process in the form of a graph.SIST EN 1745:2004
EN 1745:2002 (E)11Key110,dry (W/mK)2Upper limit
value3Mean
value4Lower limit
value5Curve resulting from tabulated values (annex A)6Parallel curve drawn through point A710 % of production8Mean density990 % of production10Product density range11Density (kg/m2)Figure 1 — Derivation of the basic -valueNOTEFor factory production control purposes thermal conductivity may be controlled indirectly from the drydensity of the material.4.3 Design RU- or U-values for solid masonry units and mortarsFrom the basic -values, design RU- or U-values are calculated using the moisture conversioncoefficients given in annex A for each type of material and the nationally given design moisturecontent for a certain material in a certain application. The calculation shall be done according toEN ISO 10456, using the following formulae:m12F or m12FRRwith)(m12feF or )(12uufmueFSIST EN 1745:2004
EN 1745:2002 (E)125 Procedures to determine design thermal values (RU or equivalent U) ofmasonry built from solid masonry units and mortar5.1 Test measurementsIf a manufacturer decides to determine RU or equivalent U-values from test measurements, thefollowing procedure shall be used: Select test samples from 3 different production batches. From each of these batches erect one wall. Measure the thermal resistance and/or the equivalent thermal conductivity on each of thosewalls, following EN ISO 8990 or EN 1934. Calculate the mean thermal resistance and/or equivalent thermal conductivity from the 3 testresults. Obtain the design value for the thermal resistance and/or the equivalent thermal conductivity ofthe masonry wall on the basis of this mean value, taking into account the design moisturecontents given nationally.Quote the masonry unit type and its respective EN from EN 771 series, the accompanying unit mass(dry mass or mass at the nationally given design moisture content) and the geometry of the testspecimens as well as the thermal conductivity and the geometry (e.g. twin strip) of the mortar jointused for the measurement.For the calculation of RU or equivalent U-values at any other design moisture contents, it is necessaryto cater for the influence of moisture. The values for the moisture correction coefficients can bederived from tests, carried out at several moisture contents. Alternatively the moisture correctioncoefficient can be taken from national documents. If neither of these possibilities exists, use amoisture correction coefficient for all types of materials and geometries of 6 %, (i.e. the thermalresistance of the masonry changes 6 % per volume percent change of moisture).If there are unit types that are usually combined with different mortar types, provide thermal values forall these combinations.NOTEAs an approximation the measured values with low thermal insulation mortar may be converted to acorresponding value with high thermal insulation mortar and vice versa by a simple mean value calculation of thethermal coupling factors (1/R) according to the area ratio of mortar joints and units, provided that the ratio of thethermal resistances of the masonry unit layer and the mortar layer is not more than 1:5.5.2 Calculation methods5.2.1 GeneralDetermine the -values of the materials, which are necessary input parameters for calculationmethods, either according to 4.2.1 or 4.2.2.Determine the RU- or equivalent U-value of the masonry according to the following procedure:basic -value (10,dry)
moisture correction (see 4.3)
U-value of the material calculation RU- or equivalent U-value of the masonry.SIST EN 1745:2004
EN 1745:2002 (E)13The moisture correction coefficients for materials given in annex A shall be used.5.2.2 Numerical calculationThe requirements for appropriate calculation programs (accuracy, boundary conditions, etc.) are givenin annex D.NOTENumerical calculation procedures (e.g. Finite Element Method or Finite Difference Method, etc.) leadto accurate calculation results, even where there are large differences between the lambda-values of the unitmaterial and the masonry mortar.5.2.3 Simplified calculationThe method described in EN ISO 6946:1996 may be used.6 Procedures to determine design thermal values (RU or equivalent U) formasonry units with formed voids and composite masonry units and for wallsbuilt from such units and mortar6.1 GeneralThe thermal properties of masonry units with formed voids cannot fully be determined from thelambda-value of the material, there is also a high influence from the shape and the geometry of theholes in the unit.The RU- or equivalent U-values of masonry built from masonry units with formed voids can bedetermined either from tables or from test measurements carried out on masonry samples or fromcalculations. The RU- or equivalent U-values of masonry built from composite masonry units can bedetermined either from test measurements carried out on masonry samples or from calculations.6.2 RU- or equivalent U-values of masonry units with formed voids and compositemasonry unitsAt present there are several different numerical methods in use (e.g. Finite Difference, Finite Element)for the calculation of the thermal properties of masonry units with formed voids or composite masonryunits. The thermal conductivities of the materials are necessary input parameters for suchcalculations, and these have to be determined according to 4.3.The requirements for appropriate calculation programs (accuracy, boundary conditions, etc.) are givenin annex C.The method described in EN ISO 6946:1996 may also be used.6.3 RU- or equivalent U-values of masonry built from masonry units with formedvoids or composite masonry units and mortar6.3.1 Tabulated values6.3.1.1 Application of annex BExamples for basic values for the determination of RU- or equivalent U-values of masonry built frommasonry units with formed voids are given in annex B, differentiated by: material;SIST EN 1745:2004
EN 1745:2002 (E)14 geometry of the units and geometry of formed voids; -value of the material of the masonry units; -value of the mortar.No tabulated values for composite masonry units are given in annex B.The tabulated basic R- or equivalent -values should be taken as the basis for the calculation of anynational design values, which are dependent on the climatic conditions and the application. Thevalues for the moisture correction coefficients can be derived from tests, carried out at severalmoisture contents. Alternatively the moisture correction coefficients can be taken from nationaldocuments. If such values do not exist, the moisture correction coefficient for all types of materialsand geometries should be taken as 6 % (i.e. the thermal resistance of the masonry changes 6 % pervolume percent change of moisture). It is also possible to determine a design value by correcting the-value of each material for moisture using the correction coefficients given in annex A and consultingthe tables in annex B for RU- or equivalent U of the masonry.The values for the thermal conductivity of the materials are 10,dry-values. If no measured values areavailable for the thermal conductivity of the masonry units material and the mortar, the tabulatedvalues from annex A may be used.Linear interpolation may be used for material conductivities between the values given in the tables inannex B.6.3.1.2 Alternative application of annex BThe tabulated values have been calculated assuming a certain height and length of the masonryunits, a certain thickness of the horizontal mortar joints and no mortar in the vertical joints (the "basicdimensions" are given for each geometry class). For masonry built from units with a different height,the influence of the mortar joints may be taken into account as follows. The same procedure may beused to determine values for masonry with vertical mortar joints in those cases where no separatevalues are given. These methods are valid for all available masonry units.Calculate the U-value of the masonry from the equivalent thermal conductivity in the table using theformula:whereUTis the thermal transmittance of the wall, in W/m2KRsi, Rseare the internal and external surface resistance in m2K/W according to EN ISO 6946dis the thickness of the wall in mequis the tabulated value of the equivalent thermal conductivity of the wall in W/(mK)Calculate the thermal transmittance of the masonry units without mortar as follows:RdRUseequsiT+
+ 1 = SIST EN 1745:2004
EN 1745:2002 (E)15Calculate the thermal transmittance of masonry built from units with another height, as follows:wherehUis the unit height which was the basis for the calculation of the tabulated value in mmhMis the height of the mortar joint which was basis for the calculation of the tabulatedvalue in mmh= hU + hM in mmUUis the thermal transmittance of the units without mortar influence in W/(m2K)UMis the thermal transmittance of the mortar
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