SIST EN ISO 23993:2008

SLOVENSKI STANDARD
SIST EN ISO 23993:2008
01-julij-2008
7RSORWQRL]RODFLMVNLSURL]YRGL]DRSUHPRVWDYELQLQGXVWULMVNHLQãWDODFLMH
'RORþHYDQMHSURMHNWQHWRSORWQHSUHYRGQRVWL,62
Thermal insulation products for building equipment and industrial installations -
Determination of design thermal conductivity (ISO 23993:2008)
Wärmedämmung an betriebstechnischen Anlagen in der Industrie und der technischen
Gebäudeausrichtung - Bestimmung der Betriebswärmeleitfähigkeit (ISO23993:2008)
Produits d'isolation thermique pour les équipements de bâtiment et des installations
industrielles - Détermination de la conception de la conductivité thermique (ISO
23993:2008)
Ta slovenski standard je istoveten z: EN ISO 23993:2008
ICS:
27.220 Rekuperacija toplote. Heat recovery. Thermal
Toplotna izolacija insulation
91.100.60 0DWHULDOL]DWRSORWQRLQ Thermal and sound insulating
]YRþQRL]RODFLMR materials
SIST EN ISO 23993:2008 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 23993:2008

---------------------- Page: 2 ----------------------

SIST EN ISO 23993:2008
EUROPEAN STANDARD
EN ISO 23993
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2008
ICS 91.120.10; 27.220

English Version
Thermal insulation products for building equipment and industrial
installations - Determination of design thermal conductivity (ISO
23993:2008)
Produits isolants thermiques pour l'équipements du Wärmedämmung an betriebstechnischen Anlagen in der
bâtiment et les installations industrielles - Détermination de Industrie und der technischen Gebäudeausrichtung -
la conductivité thermique utile (ISO 23993:2008) Bestimmung der Betriebswärmeleitfähigkeit (ISO
23993:2008)
This European Standard was approved by CEN on 3 January 2008.
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. 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 language 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, Finland,
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
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23993:2008: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO 23993:2008
EN ISO 23993:2008 (E)
Contents Page
Foreword.3
2

---------------------- Page: 4 ----------------------

SIST EN ISO 23993:2008
EN ISO 23993:2008 (E)
Foreword
This document (EN ISO 23993:2008) has been prepared by Technical Committee CEN/TC 89 "Thermal
performance of buildings and building components", the secretariat of which is held by SIS, in collaboration
with Technical Committee ISO/TC 163 "Thermal performance and energy use in the built environment".
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by August 2008, and conflicting national standards shall be withdrawn at
the latest by August 2008.
Attention is drawn to the possibility that some of the elements of this 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 Standard: 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.
Endorsement notice
The text of ISO 23993:2008 has been approved by CEN as a EN ISO 23993:2008 without any modification.

3

---------------------- Page: 5 ----------------------

SIST EN ISO 23993:2008

---------------------- Page: 6 ----------------------

SIST EN ISO 23993:2008

INTERNATIONAL ISO
STANDARD 23993
First edition
2008-02-01

Thermal insulation products for building
equipment and industrial installations —
Determination of design thermal
conductivity
Produits isolants thermiques pour l'équipement du bâtiment et les
installations industrielles — Détermination de la conductivité thermique
utile




Reference number
ISO 23993:2008(E)
©
ISO 2008

---------------------- Page: 7 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2008
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2008 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Symbols . 2
5 Determination of declared thermal conductivity . 2
6 Determination of the design value of thermal conductivity . 3
7 Conversion of available data . 3
7.1 General. 3
7.2 Conversion factor for temperature difference . 3
7.3 Conversion factor for moisture . 4
7.4 Conversion factor for ageing. 5
7.5 Conversion factor for compression. 5
7.6 Conversion factor for convection . 5
7.7 Conversion factor for thickness effect. 5
7.8 Conversion factor for regular joints . 5
7.9 Additional thermal conductivity for regularly insulation-related thermal bridges,
e.g. spacers . 6
Annex A (normative) Conversion factors . 7
Annex B (informative) Examples of determination of the design thermal conductivity. 19
Annex C (informative) Approximate values of conversion factors . 22
Bibliography . 30

© ISO 2008 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 23993 was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 89, Thermal performance of buildings and building components, in collaboration with ISO Technical
Committee ISO/TC 163, Thermal performance and energy use in the built environment, Subcommittee SC 2,
Calculation methods, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This International Standard is one of a series of standards on methods for the design and evaluation of the
thermal performance of building equipment and industrial installations.

iv © ISO 2008 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
Introduction
The establishment of design values for thermal conductivity for the calculation of the thermal performance of
insulation systems for building equipment and industrial installations requires a consideration of various
possible influences affecting the thermal properties of the insulation products employed due to the operational
conditions of any individual insulation system.
Among these influences could be:
⎯ the non-linearity of the thermal conductivity curve over the temperature range in which the insulant may
be employed;
⎯ the thickness effect;
⎯ the effect of moisture in the insulant;
⎯ ageing effects, beyond those already incorporated in the declared value;
⎯ special installation effects such as single- or multi-layered installation.
In this International Standard, the conversion factors F, that need to be used in a variety of applications for a
variety of insulation products, are given and the principles and general equations as well as some guidance
for the establishment of design values for the calculation of the thermal performance of insulation systems are
described. The conversion factors valid for commonly employed insulation products are given in annexes.
They are well established in some cases and for some materials. Where experience is lacking and conversion
factors cannot be established accurately, they are given in the form of an “educated estimate” so that the
calculation result will be on the safe side, i.e. the calculated heat transfer will be greater than that actually
occurring when the calculation has obeyed the rules of this International Standard.

© ISO 2008 – All rights reserved v

---------------------- Page: 11 ----------------------

SIST EN ISO 23993:2008

---------------------- Page: 12 ----------------------

SIST EN ISO 23993:2008
INTERNATIONAL STANDARD ISO 23993:2008(E)

Thermal insulation products for building equipment and
industrial installations — Determination of design thermal
conductivity
1 Scope
This International Standard gives methods to calculate design thermal conductivities from declared thermal
conductivities for the calculation of the thermal performance of building equipment and industrial installations.
These methods are valid for operating temperatures from −200 °C to +800 °C.
The conversion factors, established for the different influences, are valid for the temperature ranges indicated
in the relevant clauses or annexes.
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 8497, Thermal insulation — Determination of steady-state thermal transmission properties of thermal
insulation for circular pipes
ISO 9053, Acoustics — Material for acoustical applications — Determination of airflow resistance
ISO 9229, Thermal insulation — Vocabulary
ISO 13787, Thermal insulation products for building equipment and industrial installations — Determination of
declared thermal conductivity
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7345, ISO 9229 and the following
apply.
3.1
declared thermal conductivity
value of the thermal conductivity of a material or product used for building equipment and industrial
installations:
⎯ based on measured data at reference conditions of temperature and humidity;
⎯ given as a limit value, according to the determination method in ISO 13787;
⎯ corresponding to a reasonable expected service lifetime under normal conditions
© ISO 2008 – All rights reserved 1

---------------------- Page: 13 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
3.2
design thermal conductivity
value of thermal conductivity of an insulation 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 equipment or industrial installation
4 Symbols
Symbol Quantity Unit
3 .
a compressibility coefficient m /(kg K)

C
D internal diameter of the layer m
d layer thickness m
d system thickness including air gap m

g
F overall conversion factor for thermal conductivity —
F ageing conversion factor —

a
F compression conversion factor —
C
F convection conversion factor —
c
F thickness conversion factor —
d
f thickness conversion coefficient —

d
F joint factor —

j
F moisture conversion factor —
m
3 3
f moisture conversion coefficient volume by volume m /m

ψ
F temperature difference conversion factor —

∆θ
u moisture content mass by mass kg/kg
θ Celsius temperature °C
.
λ declared thermal conductivity W/(m K)

d
.
λ design thermal conductivity W/(m K)

.
λ integrated thermal conductivity W/(m K)
.
∆λ additional thermal conductivity due to thermal bridges, such as spacers, which W/(m K)
are regular parts of the insulation
3
ρ apparent density kg/m
3 3
ψ moisture content volume by volume m /m
5 Determination of declared thermal conductivity
Declared thermal conductivities shall be determined according to ISO 13787.
The product shall be described by its characteristics including a clear identification of the materials, the type
of facing if any, the structure, the blowing agent, the thickness and any other parameters having a possible
influence on thermal conductivity.
The declared thermal conductivity shall be determined either at a thickness large enough to neglect the
thickness effect or, for smaller thicknesses, based on measurements at those thicknesses.
2 © ISO 2008 – All rights reserved

---------------------- Page: 14 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
6 Determination of the design value of thermal conductivity
The design value of thermal conductivity shall be determined from the declared thermal conductivity for the set
of conditions corresponding to the conditions of the expected application. Possible influences include the
following:
a) the average operating temperature, together with the hot and cold surface temperatures;
b) the average moisture content expected when the material is in equilibrium with a defined atmosphere
(temperature and relative humidity);
c) the ageing effect according to the application, if not included in the declared value;
d) the compression applied in the application;
e) the convection effect in the material;
f) the thickness effect;
g) the open joint effect;
h) the insulation-related thermal bridges, (thermal bridges that are regular part of the insulation system, e.g.
spacers), which are taken into account via a term ∆λ.
The design value of thermal conductivity shall be obtained either
⎯ from a declared thermal conductivity converted to the conditions of the application using Equation (1):
Error! Objects cannot be created from editing field codes. (1)
where the additional term ∆λ is obtained according to 7.9 and the overall conversion factor F is given by:
Error! Objects cannot be created from editing field codes. (2)
⎯ or from values measured under application conditions.
NOTE Approximate values for F can be found in the informative Annex C.
7 Conversion of available data
7.1 General
Values of the different conversion factors for some insulating materials and operating conditions are given in
Annex A. Conversion factors derived from measured values according to the appropriate test methods, e.g.
EN 12667 or ISO 8497, may be used instead of the values in Annex A. If the material does not correspond to
the conditions for which the factors are given in Annex A, then the conversion factors derived from measured
values shall be used.
7.2 Conversion factor for temperature difference
If the design thermal conductivity is requested at the same reference mean temperature and if the hot and
cold surface temperatures are the same as for the declared thermal conductivity, no conversion is needed
(F = 1).
∆θ
© ISO 2008 – All rights reserved 3

---------------------- Page: 15 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
In the case of thermal conductivity measurement made with the pipe tester (ISO 8497), no conversion is
needed when the measurement is carried out with the full temperature difference ∆θ.
If the design thermal conductivity is to be determined at another temperature from declared thermal
conductivities given in the form of a table of values at different temperatures, interpolation between values in
the table shall be based on the use of a best-fit equation such as a regression polynomial, of an order
sufficient to provide a correlation coefficient, r W 0,98.
If the design thermal conductivity is needed at the same reference mean temperature, but for another hot and
cold surface temperature difference, than that used for determining the declared thermal conductivity, the
conversion factor F shall be determined according to the procedure given in A.1 of Annex A.
∆θ
If the thermal conductivity measurement has been carried out with the full temperature difference, F = 1. If
∆θ
the thermal conductivity measurement has been carried out with a ∆θ not exceeding 50 K, the procedure for
non-linearity applies.
If the design thermal conductivity is needed at another mean temperature than that of the declared thermal
conductivity and with another temperature difference, the procedures outlined above shall be followed
successively. As an alternative, the influence of the non-linearity of the thermal conductivity curve may be
taken into account by integrating the measured curve as given by Equation (3):
θ
1
2
λ= λθ dθ (3)
()
∫
θ
θθ−
1
21
The temperature difference conversion factor is given by:
λ
F = (4)
∆θ
λ()θ
where (λθ) is the value read on the curve at the reference temperature.
7.3 Conversion factor for moisture
The conversion factor F for volume-related moisture content shall be determined as follows:
m
f ψ −ψ
( )
ψ 21
F = e (5)
m
where
f is the moisture content conversion coefficient volume by volume;
ψ
ψ is the moisture content volume by volume for the determination of declared value of thermal
1
conductivity;
ψ is the moisture content volume by volume for the actual application.
2
The content of moisture in a given application shall be determined either
⎯ by measurements carried out in the conditions of the expected application, or
⎯ by theoretical calculations using proven methods such as those given in ISO 15758 based on measured
values as described in ISO 12572, provided the assumptions on which they are based are met.
NOTE A possible test method to determine moisture content is given in EN 12088. If needed for the application, the
time period indicated in EN 12088 can be extended.
Some values of the coefficient f are given in A.2 of Annex A.
ψ
4 © ISO 2008 – All rights reserved

---------------------- Page: 16 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
7.4 Conversion factor for ageing
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 (see procedure in the product standard, where applicable).
No conversion is needed when the declared thermal conductivity or resistance already takes account of
ageing or when the ageing effect has been determined in conditions which do not significantly differ from the
design set of conditions.
If the set of conditions for the design thermal conductivities significantly differs from that in which the ageing
effect of the declared thermal conductivity has been determined, an ageing test in the set of conditions of the
design thermal conductivities shall be carried out.
If a conversion factor F is used, it shall allow for 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 for building equipment is often taken as 50 years.
NOTE 2 No conversion coefficients are given in this International Standard to derive the ageing conversion factor F .
a
No ageing conversion factor shall be used for mineral wool, ceramic fibre, calcium-magnesium silicate fibre,
calcium silicate, flexible elastomeric foam and cellular glass.
7.5 Conversion factor for compression
For compressible insulation products, the apparent density may change when the product is subject to load.
The influence on the thermal conductivity shall be taken into account by the factor F , which shall be
C
calculated according to A.3.
7.6 Conversion factor for convection
The effect of convection in the case of vertical insulation layers shall be taken into account by a convection
factor F .
c
The factor F shall be calculated according to A.4.
c
7.7 Conversion factor for thickness effect
For insulation materials permeable to radiation, the thermal conductivity changes with increasing thickness. If
the design thermal conductivity is needed at other thicknesses than those of the declared thermal conductivity,
the factor F shall be determined according to A.5.
d
7.8 Conversion factor for regular joints
The influence of joints on the design thermal conductivity shall be addressed by the conversion factor F ,
j
which shall be calculated according to A.6.
The conversion factor F shall be applied if the thermal conductivity has been measured in accordance with
j
ISO 8497, with a pipe tester having fewer joints than the actual application.
© ISO 2008 – All rights reserved 5

---------------------- Page: 17 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
7.9 Additional thermal conductivity for regularly insulation-related thermal bridges,
e.g. spacers
7.9.1 General
Components in the insulating layer which are regularly-spaced insulation-related thermal bridges like spacers
are taken into account by adding ∆λ to the corrected thermal conductivity λ of the installed insulation product
d
according to Equation (1).
Plant-related and irregularly-spaced insulation-related thermal bridges, e.g. pipe mountings, supports,
armatures and frontal plates are thermal bridges which have to be considered as additional heat losses, e.g.
as described in ISO 12241.
7.9.2 Spacers
7.9.2.1 Spacers for sheet metal pipeline jackets
The additional thermal conductivity depends on a number of variables. The values indicated in the following
are approximate values and apply to common insulating layer thicknesses from 100 mm to 300 mm and
common insulation systems for heat protection.
NOTE 1 Reference [9] in the Bibliography provides possible procedures for special insulation systems.
Additions to thermal conductivity
for steel spacers ∆λ = 0,010 W/(m·K)
for austenitic steel spacers ∆λ = 0,004 W/(m·K)
for ceramic spacers ∆λ = 0,003 W/(m·K)
NOTE 2 These values can be used in the range of 50 mm to 200 mm, see Reference [10].
7.9.2.2 Spacers for sheet metal jackets for walls
Spacers of steel in the form of a flat bar
2
30 mm × 3 mm ∆λ = 0,003 5 W/(m·K)/(spacers/m )
2
40 mm × 4 mm ∆λ = 0,006 0 W/(m·K)/(spacers/m )
2
50 mm × 5 mm ∆λ = 0,008 5 W/(m·K)/(spacers/m )
7.9.3 Mechanical fasteners penetrating an insulation layer
Additions ∆λ to thermal conductivity to account for fasteners depend on the number of fasteners per square
2
metre (m ) and on the geometry. The total addition is calculated by:
∆=λ n∆λ (6)
i
where ∆λ is the additional conductivity due to fastener i (i = 1 … n).
i
2
For steel fasteners, diameter 4 mm, 9 fasteners/m : ∆λ = 0,006 W(m⋅K).
2
For austenitic steel fasteners, diameter 4 mm, 9 fasteners/m : ∆λ = 0,004 W(m⋅K).
6 © ISO 2008 – All rights reserved

---------------------- Page: 18 ----------------------

SIST EN ISO 23993:2008
ISO 23993:2008(E)
Annex A
(normative)

Conversion factors
A.1 Conversion factors for the influence of the non-linearity of the thermal
conductivity versus temperature curve
When not using directly integrated values for the thermal conductivity or calculation based on a polynomial
expression of the thermal conductivity, the influence of the non-linearity of the thermal conductivity versus
temperature curve for insulation materials shall be taken into account by using the temperature difference
conversion factor F given in Table A.1.
∆θ
Table A.1 — Temperature difference conversion factor F
∆θ

a
Product type Apparent density
Temperature difference
3
kg/m
K
100 250 450
Stone wool
mat 50 to 70 1,04 1,08 1,12
board 80 to 120 1,02 1,05 1,1
130 to 150 1,0 1,02 1,05
> 160 1,0 1,0 1,02
lamella mat 30 to 40 1,02 1,10 1,15
50 to 60 1,01 1,08 1,12
Glass wool
mat 30 to 45 1,03 1,06 1,10
board 50 to 75 1,01 1,04 1,07
lamella mat 30 1,0 1,08 —
Calcium-magnesium
silicate
mat 80 to 110 1,02 1,06 1,10
board
Cellular glass 120 to 200 1,02 1,04 1,06
Perlite 60 to 80 1,01 1,02 1,05
Calcium silicate 100 to 200 1,01 1,02 1,05
...