SIST EN ISO 10456:2008

SLOVENSKI oSIST prEN ISO 10456:2005

PREDSTANDARD
junij 2005
Gradbeni materiali in proizvodi - Higrotermalne lastnosti - Tabelirane
računske vrednosti in postopki za določevanje nazivnih in računskih
vrednosti toplotnih vrednosti (ISO/DIS 10456:2005)
Building materials and products - Hygrothermal properties -Tabulated design values
and procedures for determining declared and design thermal values (ISO/DIS
10456:2005)
ICS 91.100.01; 91.120.10 Referenčna številka
oSIST prEN ISO 10456:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD
DRAFT
prEN ISO 10456
NORME EUROPÉENNE

EUROPÄISCHE NORM

April 2005
ICS 91.120.10 Will supersede EN ISO 10456:1999
English version
Building materials and products - Hygrothermal properties -
Tabulated design values and procedures for determining
declared and design thermal values (ISO/DIS 10456:2005)
Matériaux et produits du bâtiment - Propriétés Baustoffe und -produkte - Wärme- und feuchtetechnische
hygrothermiques - Tableaux des valeurs de conception et Eigenschaften - Tabellierte Bemessungswerte und
procédures pour la détermination des valeurs thermiques Verfahren zur Bestimmung der wärmeschutztechnischen
déclarées et de conception (ISO/DIS 10456:2005) Nenn- und Bemessungswerte (ISO/DIS 10456:2005)
This draft European Standard is submitted to CEN members for parallel enquiry. It has been drawn up by the Technical Committee
CEN/TC 89.

If this draft becomes a European Standard, 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 standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN ISO 10456:2005: E
worldwide for CEN national Members.

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prEN ISO 10456:2005 (E)




Foreword

This document (prEN ISO 10456:2005) has been prepared by Technical Committee ISO/TC 163 "Thermal
insulation" in collaboration with Technical Committee CEN/TC 89 "Thermal performance of buildings and
building components", the secretariat of which is held by SIS.

This document is currently submitted to the parallel Enquiry.

This document will supersede EN ISO 10456:1999.


Endorsement notice

The text of ISO/DIS 10456:2005 has been approved by CEN as prEN ISO 10456:2005 without any
modifications.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 10456
ISO/TC 163/SC 2 Secretariat: SN
Voting begins on: Voting terminates on:
2005-04-07 2005-09-07
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION
Building materials and products — Hygrothermal properties —
Tabulated design values and procedures for determining
declared and design thermal values
Matériaux et produits du bâtiment — Propriétés hygrothermiques — Tableaux des valeurs de conception et
procédures pour la détermination des valeurs thermiques déclarées et de conception
[Revision of second edition (ISO 10456:1999)]
ICS 91.120.10

ISO/CEN PARALLEL ENQUIRY
The CEN Secretary-General has advised the ISO Secretary-General that this ISO/DIS covers a subject
of interest to European standardization. In accordance with the ISO-lead mode of collaboration as
defined in the Vienna Agreement, consultation on this ISO/DIS has the same effect for CEN
members as would a CEN enquiry on a draft European Standard. Should this draft be accepted, a
final draft, established on the basis of comments received, will be submitted to a parallel two-month FDIS
vote in ISO and formal vote in CEN.
In accordance with the provisions of Council Resolution 15/1993 this document is circulated in
the English language only.
Conformément aux dispositions de la Résolution du Conseil 15/1993, ce document est distribué
en version anglaise seulement.
To expedite distribution, this document is circulated as received from the committee secretariat.
ISO Central Secretariat work of editing and text composition will be undertaken at publication
stage.
Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du
secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au
Secrétariat central de l'ISO au stade de publication.
THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE
REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
© International Organization for Standardization, 2005

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ISO/DIS 10456
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©
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ISO/DIS 10456
Contents Page
1 Scope.1
2 Normative references.1
3 Terms, definitions, symbols and units.1
3.1 Terms and definitions .1
3.2 Symbols and units.2
4 Test methods and test conditions.3
4.1 Tests for thermal properties.3
4.2 Tests for moisture properties .3
5 Determination of declared thermal values.3
6 Determination of design thermal values.5
6.1 General .5
6.2 Design values derived from declared values .5
6.3 Design values derived from measured values .5
7 Conversion of thermal values .5
7.1 General .5
7.2 Conversion for temperature .5
7.3 Conversion for moisture.6
7.4 Age conversion.7
7.5 Natural convection .7
8 Tabulated design hygrothermal values.8
8.1 General .8
8.2 Design thermal values .8
8.3 Design moisture values .8
Annex A (normative) Conversion coefficients for temperature.20
Annex B (informative) Examples of calculations.24
B.1 Declared value determined from 10 measured samples.24
B.2 Determination of design value from declared value.25
Annex C (informative) Statistical calculations.27
C.1 Generation of fractile values .27
C.2 Conversion between mean and fractile values .27

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ISO/DIS 10456
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
ISO 10456 was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in the
built environment, Subcommittee SC 2, Calculation methods.
This third edition cancels and replaces the second edition (ISO 10456:1999). A summary of the principal
changes to the clauses that have been technically revised is given below.
Clause Changes
Title; extension of This standard now includes tabulated design values of thermal and moisture
scope properties of materials. That has been envisaged as a separate standard,
but because of the substantial cross-referencing that would be involved, it
was decided to merge them.
Introduction Introduction added.
1 Moisture coefficients valid only between 0°C and 30°C
4.2 New sub-clause.
7.2 Text extended with general information about climates.
7.4 Clarification that ageing factors are not applied if taken account of in
declared values.
7.5 New sub-clause on convection in insulating materials
8 New clause giving tabulated design values (Tables 3, 4, 5). The data are
from EN 12524.
Annex A Data reviewed for XPS and PU. [Information awaited for PF.]

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ISO/DIS 10456
Introduction
Heat and moisture transfer calculations require design values of thermal and moisture properties for materials
used in building applications.
Design values can be derived from declared values that are based on measured data on the product
concerned: that is usually the case for thermal insulation materials. Where the design conditions differ from
those of the declared value, the data needs to be converted to the applicable conditions and this standard
provides the methods and data for so doing.
For materials for which measured values are not available, design values can be obtained from tables. This
standard provides such tabulated information based on the compilation of existing data (see Bibliography).
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DRAFT INTERNATIONAL STANDARD ISO/DIS 10456

Building materials and products — Hygrothermal properties —
Tabulated design values and procedures for determining
declared and design thermal values
1 Scope
This standard specifies methods for the determination of declared and design thermal values for thermally
homogeneous building materials and products, together with procedures to convert values obtained under one
set of conditions to those valid for another set of conditions. These procedures are valid for design ambient
temperatures between -30 °C and +60 °C.
It gives conversion coefficients for temperature and for moisture. These coefficients are valid for mean
temperatures between 0 °C and 30 °C.
It also gives design data in tabular form for use in heat and moisture transfer calculations, for thermally
homogeneous materials and products commonly used in building construction.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 7345, Thermal insulation - Physical quantities and definitions
ISO 8301, Thermal insulation — Determination of steady-state specific thermal resistance and related
properties — Heat flow meter apparatus
ISO 8302, Thermal insulation — Determination of steady-state thermal resistance and related properties —
Guarded hot plate apparatus
ISO 8990, Thermal insulation — Determination of steady-state thermal transmission properties — Calibrated
and guarded hot box
ISO 9346, Thermal insulation - Mass transfer - Physical quantities and definitions
ISO 12572, Hygrothermal properties of building materials and products – Determination of water vapour
resistance properties
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this standard the terms and definitions in ISO 7345 apply, together with the following.
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ISO/DIS 10456
3.1.1
declared thermal value
expected value of a thermal property of a building material or product
 assessed from measured data at reference conditions of temperature and humidity;
 given for a stated fraction and confidence level;
 corresponding to a reasonable expected service lifetime under normal conditions
3.1.2
design thermal value
design thermal conductivity or design thermal resistance
NOTE A given product can have more than one design value, for different applications or environmental conditions.
3.1.3
design thermal conductivity
value of thermal conductivity of a building material or product under specific external and internal conditions
which can be considered as typical of the performance of that material or product when incorporated in a
building component
3.1.4
design thermal resistance
value of thermal resistance of a building product under specific external and internal conditions which can be
considered as typical of the performance of that product when incorporated in a building component
3.1.5
material
piece of a product irrespective of its delivery form, shape and dimensions, without any facing or coating
3.1.6
product
final form of a material ready for use, of given shape and dimensions and including any facings or coatings
3.2 Symbols and units
Symbol Quantity Unit
c specific heat capacity at constant pressure J/(kg·K)
p
F ageing conversion factor -
a
F moisture conversion factor -
m
F
temperature conversion factor -
T
-1
f
temperature conversion coefficient K
T
1)
f kg/kg
moisture conversion coefficient mass by mass
u

1)
f m³/m³
moisture conversion coefficient volume by volume
ψ
R thermal resistance
m²⋅K/W
s water vapour diffusion-equivalent air layer thickness m
d
T temperature K
u moisture content mass by mass kg/kg

1) For conversion of thermal properties
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ISO/DIS 10456
thermal conductivity
λ W/(m⋅K)
water vapour resistance factor -
µ
density kg/m³
ρ
moisture content volume by volume m³/m³
ψ

4 Test methods and test conditions
4.1 Tests for thermal properties
Measured values of thermal conductivity or thermal resistance shall be obtained using the following methods,
or equivalent national methods:
 guarded hot plate in accordance with ISO 8302;
 heat flow meter in accordance with ISO 8301;
 hot box in accordance with ISO 8990.
To avoid conversions, it is recommended that measurements be conducted under conditions corresponding to
the selected set of conditions given in Table 1.
The mean test temperature should be chosen so that the application of the temperature coefficients does not
introduce a change of more than 2 % from the measured value.
The following testing conditions are required:
 measured thickness and density for identification;
 mean test temperature;
 moisture content of the specimen during test.
For aged materials:
 age of the specimen and conditioning procedures before testing.
4.2 Tests for moisture properties
Measured values of water vapour resistance factor or water vapour diffusion-equivalent air layer thickness
shall be obtained using ISO 12572, or an equivalent national method.
5 Determination of declared thermal values
A declared thermal value shall be given under one of the sets of conditions a or b with reference temperature
10 °C (I) or 23 °C (II) in Table 1.
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ISO/DIS 10456
Table 1 — Declared value conditions
Sets of conditions
Property I (10 °C) II (23 °C)
a b a b
Reference temperature 10 °C 10 °C 23 °C 23 °C
Moisture u u u u
dry 23,50 dry 23,50
Ageing aged aged aged aged
u is a low moisture content reached by drying according to specifications or standards for the material concerned.
dry
u is the moisture content when in equilibrium with air at 23 °C and relative humidity of 50 %.
23,50

The declared value shall be determined either at a thickness large enough to neglect the thickness effect, or
the declared values for smaller thicknesses shall be based on measurements at those thicknesses.
The data used shall be either
 directly measured values according to the test methods given in Clause 4, or
 obtained indirectly by making use of an established correlation with a related property such as density.
When all data have not been measured under the same set of conditions, they shall first be brought to one set
of conditions (see Clause 7). Then a statistical single value estimate shall be calculated. Annex C refers to
International Standards on statistics that may be used.
During calculations no value shall be rounded to less than three significant figures.
The declared value is the estimated value of the statistical single value, rounded according to the following
rules:
a) for thermal conductivity given in watts per metre kelvin [W/(m⋅K)]:
0,08:
  λ ≤ rounding to nearest higher 0,001 W/(m⋅K)
0,08 0,20:
< λ ≤ rounding to nearest higher 0,005 W/(m⋅K)
0,20 < λ ≤ 2,00: rounding to nearest higher 0,01 W/(m⋅K)
2,0
< λ  rounding to nearest higher 0,1 W/(m⋅K)

and/or:
2
b) for thermal resistance given in square metres kelvin per watt (m ⋅K/W) as the nearest lower value
rounded to not more than two decimals or three significant figures.
NOTE Rules for determining declared values for specific products may be specified in applicable product standards.
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ISO/DIS 10456
6 Determination of design thermal values
6.1 General
Design values can be obtained from declared values, measured values or tabulated values (see Clause 8).
Measured data can be either
 directly measured values according to the test methods given in Clause 4, or
 obtained indirectly by making use of an established correlation with a related property such as density.
If the set of conditions for declared, measured or tabulated values can be considered relevant for the actual
application, those values can be used directly as design values. Otherwise, conversion of data shall be
undertaken according to the procedure given in Clause 7.
The design value shall be rounded according to the rules given in Clause 5:
 for thermal conductivity, as the nearest higher value in watts per metre kelvin [W/(m⋅K)];
2
 for thermal resistance, as the nearest lower value in square metres kelvin per watt (m ⋅K/W).
6.2 Design values derived from declared values
When the design value is calculated from the declared value and is based on the same statistical evaluation,
the declared value shall be converted to the design conditions.
Information on how to derive design values based on another statistical evaluation different from the one
applicable to the declared value is given in Annex C.
6.3 Design values derived from measured values
When necessary all data shall first be converted to the design conditions. Then a statistical single value
estimate shall be calculated. Annex C refers to International Standards on statistics that can be used.
7 Conversion of thermal values
7.1 General
Conversions of thermal values from one set of conditions (λ , R ) to another set of conditions (λ , R ) are
1 1 2 2
carried out according to the following expressions:
λ = λ ⋅ F ⋅ F ⋅ F (1)
2 1 T m a
R
1
R = (2)
2
F ⋅ F ⋅ F
T m a
Conversion coefficients may be taken from the applicable tables in this standard. Alternatively they may be
derived from measured data obtained according to the test methods referred to in 4.1.
7.2 Conversion for temperature
The factor F for temperature is determined by:
T
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ISO/DIS 10456
f (T −T )
T 2 1
F = e (3)
T
where
f is the temperature conversion coefficient;
T
T is the temperature of the first set of conditions;

1
T is the temperature of the second set of conditions.
2
Values of the temperature conversion coefficient for insulation materials and masonry materials are given in
Annex A.
NOTE The effect of temperature on the thermal properties of other materials is generally not significant for heat
transfer calculations, and can usually be neglected.
Design thermal values should be obtained for the expected mean temperature of the material as installed in
the component in the applicable climate.

7.3 Conversion for moisture
The factor F for moisture content is determined as follows.
m
a) Conversion of moisture content given as mass by mass:
f (u −u )
u 2 1
F = e (4)
m
where
f is the moisture conversion coefficient mass by mass;
u
u is the moisture content mass by mass of the first set of conditions;

1
u is the moisture content mass by mass of the second set of conditions.

2
b) Conversion of moisture content given as volume by volume:
f (ψ −ψ )
ψ 2 1
F = e (5)
m
where
f is the moisture conversion coefficient volume by volume;

ψ
ψ is the moisture content volume by volume of the first set of conditions;
1
ψ is the moisture content volume by volume of the second set of conditions.

2
Values of the moisture conversion coefficient for insulation and masonry materials are given in Table 4.
NOTE EN 1745, Masonry and masonry products – Methods for determining design thermal values, gives information
on the thermal conductivity of masonry units in the dry state.
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ISO/DIS 10456
7.4 Age conversion
The ageing depends upon the material type, facings, structures, the blowing agent, the temperature and the
thickness of the material. For a given material the ageing effect can be obtained from theoretical models
validated by experimental data. There are no simple rules to correlate ageing over time for a given material.
If the declared thermal value takes account of ageing, no further ageing conversions shall be applied for
design thermal values.
If a conversion factor F is used, it shall allow the calculation of the aged value of the thermal property
a
corresponding to a time not less than half the working lifetime of the product in the application concerned.
NOTE 1 The working lifetime is often taken as 50 years.
NOTE 2 No conversion coefficients are given in this International Standard to derive the ageing factor F . Procedures
a
for establishing aged values or ageing factors are given in some product standards.
7.5 Natural convection
The onset of natural convection in an insulating material with an open structure depends on permeability,
thickness and temperature difference. The driving force for natural convection is described by the modified
2)
Rayleigh number, Ra , which is a dimensionless number defined for the purposes of this standard by :
m
d k∆T
6
Ra = 3 ×10 (6)
m
λ
where
∆T is the temperature difference across the insulation, in K;
d is the thickness of the insulation, in m;
3)
k is the permeability of the insulation , in m²;
λ is the thermal conductivity of the insulation without convection, in W/(m·K).
If Ra does not exceed the critical value in Table 2, no correction for natural convection shall be made.
m

g β ρ c
d k∆T
p
2) The formal definition of Ra is Ra = ⋅ where g is the acceleration due to gravity (9,81 m/s²), and for
m
m
ν λ
air, β is the thermal expansion coefficient, ρ is the density, c is the specific heat capacity at constant pressure and ν is
p
the kinematic viscosity (equal to dynamic viscosity divided by density). Equation (6) is obtained on substituting properties
for air at 10 °C given in ISO 10292, Glass in building – Calculation of the steady-state U-value (thermal transmittance) of
multiple glazing.
&
∆P η V
3) Permeability is defined for one-dimensional steady-state conditions by the equation = ⋅ where ∆P is pressure
d k A
&
difference, η is dynamic viscosity of air, V is volumetric air flow rate, and A is area. It can be obtained from measurements
of the airflow resistivity of the
...