SIST EN ISO 10077-2:2012
(Main)Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 2: Numerical method for frames (ISO 10077-2:2012)
Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 2: Numerical method for frames (ISO 10077-2:2012)
This European Standard specifies a method and gives reference input data for the calculation of the thermal transmittance of frame profiles and of the linear thermal transmittance of their junction with glazings or opaque panels.
The method can also be used to evaluate the thermal resistance of shutter profiles and the thermal characteristics of roller shutter boxes.
This European Standard also gives criteria for the validation of numerical methods used for the calculation.
This European Standard does not include effects of solar radiation, heat transfer caused by air leakage or three-dimensional heat transfer such as pin point metallic connections. Thermal bridge effects between the frame and the building structure are not included.
Wärmetechnisches Verhalten von Fenstern, Türen und Abschlüssen - Berechnung des Wärmedurchgangskoeffizienten - Teil 2: Numerisches Verfahren für Rahmen (ISO 10077-2:2012)
Dieser Teil der ISO 10077 legt ein Verfahren und Bezugseingabedaten für die Berechnung des
Wärmedurchgangskoeffizienten von Rahmenprofilen und des längenbezogenen Wärmedurchgangskoeffizienten
ihrer Verbindungsstellen mit Verglasungen oder opaken Füllungen fest.
Das Verfahren kann weiterhin zur Bewertung des Wärmedurchlasswiderstands von Rollladenprofilen und der
thermischen Eigenschaften von Rollladenkästen und ähnlichen Bauteilen (z. B. Jalousien) verwendet werden.
Dieser Teil der ISO 10077 beschreibt außerdem Kriterien, die zur Validierung von numerischen Verfahren für
die Berechnung dienen.
Dieser Teil der ISO 10077 berücksichtigt weder die Einflüsse der Sonneneinstrahlung, noch die
Wärmeübertragung infolge von Luftdurchlässigkeit, noch die dreidimensionale Wärmeübertragung, wie z. B.
durch punktförmige metallische Verbindungen. Wärmebrückenwirkungen zwischen Rahmen und Baukörper
sind ebenfalls nicht berücksichtigt.
Performance thermique des fenêtres, portes et fermetures - Calcul du coefficient de transmission thermique - Partie 2: Méthode numérique pour les encadrements (ISO 10077-2:2012)
L'ISO 10077-2:2012 donne une méthode et des données d'entrée pour le calcul du coefficient de transmission thermique des encadrements et du coefficient de transmission thermique linéique de leurs jonctions avec les vitrages ou les panneaux opaques.
Cette méthode peut également être utilisée pour évaluer la résistance thermique d'encadrements de fermetures et les caractéristiques thermiques de coffres de volet roulant et de composants similaires (par exemple stores).
L'ISO 10077-2:2012 fournit également des critères pour la validation des méthodes numériques utilisées dans ce calcul.
L'ISO 10077-2:2012 ne couvre pas les effets du rayonnement solaire ni le transfert thermique provoqué par des infiltrations d'air ou les transferts thermiques tridimensionnels créés par exemple par des liaisons métalliques ponctuelles. Les effets des ponts thermiques entre les encadrements et la structure du bâtiment ne sont pas pris en compte.
Toplotne lastnosti oken, vrat in polken - Izračun toplotne prehodnosti - 2. del: Računska metoda za okvirje (ISO 10077-2:2012)
Ta evropski standard določa metodo in podaja referenčne vhodne podatke za izračun toplotne prehodnosti profilov okvirjev in linearne toplotne prehodnosti njihovega spoja z zasteklitvijo ali prosojnimi ploščami.
Metodo je mogoče uporabiti tudi za oceno toplotne upornosti profilov polken in toplotnih značilnosti roletnih škatel.
Ta evropski standard določa tudi merila za ovrednotenje računskih metod za izračun.
Ta evropski standard ne zajema učinkov sončnega sevanja, prenosa toplote zaradi puščanja zraka ali tridimenzionalnega prenosa toplote, kot so točkaste kovinske povezave. Učinki toplotnih mostov med okvirjem in strukturo stavbe niso zajeti.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 10077-2:2012
01-junij-2012
1DGRPHãþD
SIST EN ISO 10077-2:2004
7RSORWQHODVWQRVWLRNHQYUDWLQSRONHQ,]UDþXQWRSORWQHSUHKRGQRVWLGHO
5DþXQVNDPHWRGD]DRNYLUMH ,62
Thermal performance of windows, doors and shutters - Calculation of thermal
transmittance - Part 2: Numerical method for frames (ISO 10077-2:2012)
Wärmetechnisches Verhalten von Fenstern, Türen und Abschlüssen - Berechnung des
Wärmedurchgangskoeffizienten - Teil 2: Numerisches Verfahren für Rahmen (ISO 10077
-2:2012)
Performance thermique des fenêtres, portes et fermetures - Calcul du coefficient de
transmission thermique - Partie 2: Méthode numérique pour les encadrements (ISO
10077-2:2012)
Ta slovenski standard je istoveten z: EN ISO 10077-2:2012
ICS:
91.060.50 Vrata in okna Doors and windows
91.120.10 Toplotna izolacija stavb Thermal insulation
SIST EN ISO 10077-2:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 10077-2:2012
---------------------- Page: 2 ----------------------
SIST EN ISO 10077-2:2012
EUROPEAN STANDARD
EN ISO 10077-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2012
ICS 91.060.50; 91.120.10 Supersedes EN ISO 10077-2:2003
English Version
Thermal performance of windows, doors and shutters -
Calculation of thermal transmittance - Part 2: Numerical method
for frames (ISO 10077-2:2012)
Performance thermique des fenêtres, portes et fermetures - Wärmetechnisches Verhalten von Fenstern, Türen und
Calcul du coefficient de transmission thermique - Partie 2: Abschlüssen - Berechnung des
Méthode numérique pour les encadrements (ISO 10077- Wärmedurchgangskoeffizienten - Teil 2: Numerisches
2:2012) Verfahren für Rahmen (ISO 10077-2:2012)
This European Standard was approved by CEN on 29 February 2012.
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-CENELEC 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-CENELEC Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, 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, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10077-2:2012: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 10077-2:2012
EN ISO 10077-2:2012 (E)
Contents Page
Foreword .3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 10077-2:2012
EN ISO 10077-2:2012 (E)
Foreword
This document (EN ISO 10077-2:2012) 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 shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by August 2012, and conflicting national standards shall be withdrawn at
the latest by August 2012.
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.
This document supersedes EN ISO 10077-2:2003.
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, Croatia, 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, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 10077-2:2011 has been approved by CEN as a EN ISO 10077-2:2012 without any
modification.
3
---------------------- Page: 5 ----------------------
SIST EN ISO 10077-2:2012
---------------------- Page: 6 ----------------------
SIST EN ISO 10077-2:2012
INTERNATIONAL ISO
STANDARD 10077-2
Second edition
2012-03-01
Thermal performance of windows, doors
and shutters — Calculation of thermal
transmittance —
Part 2:
Numerical method for frames
Performance thermique des fenêtres, portes et fermetures — Calcul du
coefficient de transmission thermique —
Partie 2: Méthode numérique pour les encadrements
Reference number
ISO 10077-2:2012(E)
©
ISO 2012
---------------------- Page: 7 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
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 2012 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
4 Calculation method . 2
4.1 General principle . 2
4.2 Validation of the calculation programme . 3
4.3 Determination of the thermal transmittance . 3
5 Treatment of solid sections and boundaries . 3
5.1 Solid materials . 3
5.2 Emissivity of surfaces . 3
5.3 Boundaries . 4
5.4 Roller shutter boxes . 4
5.5 Extensions of window frame profiles . 6
6 Treatment of cavities . 6
6.1 General . 6
6.2 Cavities in glazing . 6
6.3 Unventilated air cavities in frames and roller shutter boxes . 6
6.4 Ventilated air cavities and grooves .10
7 Report . 11
7.1 General . 11
7.2 Geometrical data .12
7.3 Thermal data .12
7.4 Results .12
Annex A (informative) Thermal conductivity of selected materials .13
Annex B (normative) Surface resistances .15
Annex C (normative) Determination of the thermal transmittance .17
Annex D (normative) Examples for the validation of calculation programmes .21
Annex E (informative) Wood species listed in Annex A .33
Bibliography .36
© ISO 2012 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(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 10077-2 was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in the
built environment, Subcommittee SC 2, Calculation methods, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 89, Thermal performance of buildings and building components,
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.
This second edition cancels and replaces the first edition (ISO 10077-2:2003), which has been technically
revised. The main changes compared to the previous edition are given in the following table:
Clause Changes
5.1 Clarified use of measured data.
5.4 Added calculation rules for roller shutter boxes and added new figure.
5.5 Added calculation rules for extensions of window frame profiles and new added figure.
Annex A Added Table A.2 — Thermal conductivity of timber species.
Annex A Added Table A.3 — Typical emissivities of metallic surfaces.
Annex B Added Table B.2 for roller shutter boxes.
C.2 Added calculation rules for the combination of frame constructions with insulating
glazing units (IGU) and Figure C.3 showing a representative metal spacer incorporated
in an IGU.
Annex D Updated Figures D.1 to D.10 for frame sections.
ISO 10077 consists of the following parts, under the general title Thermal performance of windows, doors and
shutters — Calculation of thermal transmittance:
— Part 1: General
— Part 2: Numerical method for frames
iv © ISO 2012 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
Introduction
ISO 10077 consists of two parts. The method in this part of ISO 10077 is intended to provide calculated values
of the thermal characteristics of frame profiles, suitable to be used as input data in the calculation method of
the thermal transmittance of windows, doors and shutters given in ISO 10077-1. It is an alternative to the test
method specified in EN 12412-2. In some cases, the hot box method is preferred, especially if physical and
geometrical data are not available or if the profile is a complicated geometrical shape.
Although the method in this part of ISO 10077 basically applies to vertical frame profiles, it is an acceptable
approximation for horizontal frame profiles (e.g. sill and head sections) and for products used in sloped
positions (e.g. roof windows). For calculations made with the glazing units in place, the heat flow pattern and
the temperature field within the frame are useful by-products of this calculation.
This part of ISO 10077 does not cover building façades and curtain walling. These are covered in
1)
ISO 12631 or EN 13947.
1) To be published.
© ISO 2012 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 10077-2:2012
---------------------- Page: 12 ----------------------
SIST EN ISO 10077-2:2012
INTERNATIONAL STANDARD ISO 10077-2:2012(E)
Thermal performance of windows, doors and shutters —
Calculation of thermal transmittance —
Part 2:
Numerical method for frames
1 Scope
This part of ISO 10077 specifies a method and gives reference input data for the calculation of the thermal
transmittance of frame profiles and of the linear thermal transmittance of their junction with glazing or opaque panels.
The method can also be used to evaluate the thermal resistance of shutter profiles and the thermal characteristics
of roller shutter boxes and similar components (e.g. blinds).
This part of ISO 10077 also gives criteria for the validation of numerical methods used for the calculation.
This part of ISO 10077 does not include effects of solar radiation, heat transfer caused by air leakage or
three-dimensional heat transfer such as pin point metallic connections. Thermal bridge effects between the
frame and the building structure are not included.
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 10211, Thermal bridges in building construction — Heat flows and surface temperatures — Detailed calculations
ISO 10456: 2007, Building materials and products — Hygrothermal properties — Tabulated design values and
procedures for determining declared and design thermal values
ISO 12567-2:2005, Thermal performance of windows and doors — Determination of thermal transmittance by
hot box method — Part 2: Roof windows and other projecting windows
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
EN 673, Glass in building — Determination of thermal transmittance (U-value) — Calculation method
EN 12519, Windows and pedestrian doors — Terminology
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in ISO 7345 and EN 12519 apply.
© ISO 2012 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
Symbol Definition Unit
2
A
area m
b
width, i.e. perpendicular to the direction of heat flow m
d depth, i.e. parallel to the direction of heat flow m
E intersurface emittance —
F view factor —
2
h
heat transfer coefficient W/(m ·K)
2D
L two-dimensional thermal conductance or thermal coupling coefficient W/(m·K)
l length m
2
q density of heat flow rate W/m
2
R
thermal resistance m ·K/W
T
thermodynamic temperature K
2
U thermal transmittance W/(m ·K)
2 4
σ Stefan-Boltzmann constant W/(m ·K )
ε emissivity —
λ
thermal conductivity W/(m·K)
Ψ linear thermal transmittance W/(m·K)
Subscripts
a convective (surface to surface)
e external (outdoor)
g glazing
eq equivalent
f frame
fr frame adjacent to roller shutter box
i internal (indoor)
p panel
r radiative
s space (air or gas space)
sb shutter box
se external surface
si internal surface
4 Calculation method
4.1 General principle
The calculation shall be carried out using a two-dimensional numerical method conforming to ISO 10211. The
elements shall be divided such that any further division does not change the calculated result significantly.
ISO 10211 gives criteria for judging whether sufficient sub-divisions have been used.
Vertical orientation of frame sections and air cavities is assumed for calculations using this part of ISO 10077
for the purposes of assigning equivalent thermal conductivity values (see 7.3); this applies irrespective of the
intended orientation of the actual window, including roof windows.
2 © ISO 2012 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
4.2 Validation of the calculation programme
To ensure the suitability of the calculation programme used, calculations shall be carried out on the examples
2D
described in Annex D. The calculated two-dimensional thermal conductance L shall not differ from the
corresponding values given in Table D.3 by more than ±3 %. This will lead to an accuracy of the thermal
transmittance, U, and the linear thermal transmittance Ψ, of about 5 %.
NOTE The ± deviations in Tables D.3 and D.4 are standard deviations from a round-robin and are not to be confused
with ±3 % specified above.
4.3 Determination of the thermal transmittance
The thermal transmittance of a frame section shall be determined with the glazing replaced by an insulating
panel according to Annex C, with the external and internal surface resistances taken from Annex B. The linear
thermal transmittance of the interaction of frame and glazing shall be determined from calculations with the
glazing in place and with the glazing replaced by an insulated panel.
NOTE 1 The interaction of the frame and the building structure is considered separately for the building as a whole. It
is not part of the thermal transmittance of the frame section.
NOTE 2 In the case of an overlap between the frame section and part of the wall, the linear thermal transmittance
could be negative.
5 Treatment of solid sections and boundaries
5.1 Solid materials
For the purpose of this part of ISO 10077, thermal conductivity values used for solid materials shall be obtained
according to one of the following:
— Table A.1 of this part of ISO 10077;
— tabulated values given in ISO 10456;
— product standards;
— technical approvals by a recognized national body;
— measurements according to an appropriate International Standard.
Measurements shall be used only if there is no tabulated data or data according to relevant product standards or
a technical approval. Measurements shall be performed at a mean temperature of 10 °C using the appropriate
method by an institute accredited (as specified in ISO/IEC 17025) to carry out those measurements, on samples
that have been conditioned at 23 °C and 50 % RH to constant mass (change in mass not more than 0,1 % over
24 h). To ensure that the thermal conductivity values are representative of the material (that is, that the value
incorporates likely variability of the material and the measurement uncertainty), one of the following methods
shall be used for obtaining the thermal conductivity value from measured data used in the calculations:
— The thermal conductivity is the declared value obtained from the measured data (at least three different
samples from different lots representing the usual product variation, with ageing taken into consideration)
according to a statistical evaluation as defined in ISO 10456: 2007, Annex C, 90 % fractile.
— If less than three samples, use the mean value multiplied by a factor of 1,25.
5.2 Emissivity of surfaces
Normally, the emissivity of surfaces bounding an air cavity shall have an emissivity of 0,9. Metallic surfaces
such as aluminium alloy frame, steel reinforcement and other metals/alloys have lower emissivity. Typical
values of the emissivity for metallic surfaces are given in Table A.3. Values less than 0,9 may be used only if
taken from Table A.3 or measured in accordance with an appropriate standard by an institute accredited (as
© ISO 2012 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
specified in ISO/IEC 17025) to carry out those measurements. Where based on measured values there shall
be at least three samples and the results shall be evaluated according to the statistical treatment in ISO 10456.
5.3 Boundaries
The external and internal surface resistances depend on the convective and radiative heat transfer to the external
and internal environments. If an external surface is not exposed to normal wind conditions, the convective part
may be reduced in edges or junctions between two surfaces. The surface resistances for horizontal heat flow
are given in Annex B. These values shall be used for calculations by this part of ISO 10077 irrespective of the
intended orientation of the actual window, including roof windows. Surface condensation shall be assessed
on the basis of the lowest internal surface temperature calculated using the surface resistances in Annex B.
The cutting plane of the infill and the cutting plane to neighbouring material shall be taken as adiabatic
(see Figure 3 and Annex D)
The reference temperature conditions shall be 20 °C internal and 0 °C external.
5.4 Roller shutter boxes
Calculation of the thermal transmittance of a roller shutter box shall be done with the following boundary conditions:
— the top of the roller shutter box: adiabatic;
— the bottom of the roller shutter box where it adjoins the window frame: adiabatic for a distance of 60 mm;
2
— surfaces adjacent to the internal environment: surface resistance of 0,13 m ·K/W;
2
— surfaces adjacent to the external environment: surface resistance of 0,04 m ·K/W.
The cavity within the roller shutter box shall be treated as (see Figure 1):
— if e + e ≤ 2 mm: unventilated. The equivalent thermal conductivity of an unventilated air cavity is
1 3
calculated according to 6.3. Additional hardware, e.g. brushes, gaskets etc., can be taken into account for
determination of e and e ;
1 3
— if e ≤ 35 mm: slightly ventilated. The equivalent thermal conductivity is twice that of an unventilated cavity
tot
of the same size;
— if e > 35 mm: well ventilated taking the air temperature within the cavity equal to the external air
tot
2
temperature but with a surface resistance of 0,13 m ·K/W.
The relevant height of the roller shutter box, b , used for the calculation is the projected distance between the
sb
upper and lower adiabatic boundary (see Figure 1).
The assessment may be done with insulation on either or both of the boundaries B and C indicated in Figure 1. If
that is the case, the thickness and thermal conductivity of the insulation shall be stated in the calculation report.
4 © ISO 2012 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
Dimensions in millimetres
Key
Boundaries (see Annex B):
A adiabatic boundary
B external surface resistance
C internal surface resistance
b height of the roller shutter box
sb
e , e widths of air gaps on either side of the shutter where it exits from the shutter box
1 3
e thickness of shutter
2
e e + e + e
tot 1 2 3
l frame length
fr
NOTE The window frame (boundary A) is 60 mm wide but located with respect to the roller shutter box according to the
© ISO 2012 – All rights reserved 5
---------------------- Page: 17 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
actual situation.
Figure 1 — Schematic example for the treatment of the boundaries for roller shutter boxes
5.5 Extensions of window frame profiles
For frames with special extensions overlapping the wall or other building elements, such as Z-shaped profiles,
the extensions shall be disregarded as illustrated in Figure 2. This applies to all profiles with special extensions
(e.g. H-shape) where the extensions overlap the wall or other building elements. Other boundaries shall be
treated as defined in Figure 3.
Figure 2 — Treatment of profiles with extensions (Z-shape)
NOTE 1 This approximation is for assessment of thermal transmittance. It is not appropriate for assessment of
condensation risk.
NOTE 2 The extension of the frame profile is disregarded in the calculation of the thermal transmittance of the window
(see ISO 10077-1).
6 Treatment of cavities
6.1 General
The heat flow rate in cavities shall be represented by an equivalent thermal conductivity λ . This equivalent
eq
thermal conductivity includes the heat flow by conduction, by convection and by radiation, and depends on the
geometry of the cavity and on the adjacent materials.
6.2 Cavities in glazing
The equivalent thermal conductivity of an unventilated space between glass panes in glazing shall be determined
according to EN 673. The resulting equivalent conductivity shall be used in the whole cavity, up to the edge.
NOTE The correlations for high aspect ratio cavities used in EN 673 tend to give low values for the equivalent thermal
conductivity. More accurate correlations are given in ISO 15099.
6.3 Unventilated air cavities in frames and roller shutter boxes
6.3.1 Definition
Air cavities are unventilated if they are completely closed or connected either to the exterior or to the interior
by a slit with a width not exceeding 2 mm (see Figure 3). Otherwise, the cavity shall be treated as ventilated.
6 © ISO 2012 – All rights reserved
---------------------- Page: 18 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
Dimensions in millimetres
Key
Boundaries (see Annex B): Cavities and grooves:
A adiabatic boundary
B external surface resistance
C internal surface resistance
D increased surface resistance
E glazing (see 6.2)
F unventilated cavity (see 6.3)
G slightly ventilated cavity or groove (see 6.4.1)
H well ventilated cavity or groove (see 6.4.2)
Figure 3 — Schematic example for the treatment of cavities and grooves
of a frame section and the treatment of the boundaries
NOTE Figure 3 illustrates a window. The same principles are applicable to roof windows, but the adiabatic part of the
boundary is different; an example of a roof window is shown in Figure D.5.
© ISO 2012 – All rights reserved 7
---------------------- Page: 19 ----------------------
SIST EN ISO 10077-2:2012
ISO 10077-2:2012(E)
6.3.2 Unventilated rectangular cavities
6.3.2.1 Equivalent thermal conductivity
The equivalent thermal conductivity λ of the cavity in direction 1 is given by Equation (1).
eq
d
λ = (1)
eq
R
s
where
d is the dimension of the cavity in the direction of heat flow (see Figure 2);
R
...
SLOVENSKI STANDARD
oSIST prEN ISO 10077-2:2009
01-september-2009
7RSORWQHODVWQRVWLRNHQYUDWLQSRONHQ,]UDþXQWRSORWQHSUHKRGQRVWLGHO
5DþXQVNDPHWRGD]DRNYLUMH ,62',6
Thermal performance of windows, doors and shutters - Calculation of thermal
transmittance - Part 2: Numerical method for frames (ISO/DIS 10077-2:2009)
Wärmetechnisches Verhalten von Fenstern, Türen und Abschlüssen - Berechnung des
Wärmedurchgangskoeffizienten - Teil 2: Numerisches Verfahren für Rahmen (ISO/DIS
10077-2:2009)
Performance thermique des fenêtres, portes et fermetures - Calcul du coefficient de
transmission thermique - Partie 2: Méthode numérique pour les encadrements (ISO/DIS
10077-2:2009)
Ta slovenski standard je istoveten z: prEN ISO 10077-2
ICS:
91.060.50 Vrata in okna Doors and windows
91.120.10 Toplotna izolacija stavb Thermal insulation
oSIST prEN ISO 10077-2:2009 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 10077-2:2009
---------------------- Page: 2 ----------------------
oSIST prEN ISO 10077-2:2009
EUROPEAN STANDARD
DRAFT
prEN ISO 10077-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2009
ICS 91.060.50; 91.120.10 Will supersede EN ISO 10077-2:2003
English Version
Thermal performance of windows, doors and shutters -
Calculation of thermal transmittance - Part 2: Numerical method
for frames (ISO/DIS 10077-2:2009)
Performance thermique des fenêtres, portes et fermetures - Wärmetechnisches Verhalten von Fenstern, Türen und
Calcul du coefficient de transmission thermique - Partie 2: Abschlüssen - Berechnung des
Méthode numérique pour les encadrements (ISO/DIS Wärmedurchgangskoeffizienten - Teil 2: Numerisches
10077-2:2009) Verfahren für Rahmen (ISO/DIS 10077-2:2009)
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 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
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: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN ISO 10077-2:2009: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN ISO 10077-2:2009
prEN ISO 10077-2:2009 (E)
Contents Page
Foreword .3
2
---------------------- Page: 4 ----------------------
oSIST prEN ISO 10077-2:2009
prEN ISO 10077-2:2009 (E)
Foreword
This document (prEN ISO 10077-2:2009) 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 document is currently submitted to the parallel Enquiry.
This document will supersede EN ISO 10077-2:2003.
Endorsement notice
The text of ISO/DIS 10077-2:2009 has been approved by CEN as a prEN ISO 10077-2:2009 without any
modification.
3
---------------------- Page: 5 ----------------------
oSIST prEN ISO 10077-2:2009
---------------------- Page: 6 ----------------------
oSIST prEN ISO 10077-2:2009
DRAFT INTERNATIONAL STANDARD ISO/DIS 10077-2
ISO/TC 163/SC 2 Secretariat: SN
Voting begins on: Voting terminates on:
2009-06-25 2009-11-25
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION
Thermal performance of windows, doors and shutters —
Calculation of thermal transmittance —
Part 2:
Numerical method for frames
Performance thermique des fenêtres, portes et fermetures — Calcul du coefficient de transmission
thermique —
Partie 2: Méthode numérique pour les encadrements
[Revision of first edition (ISO 10077-2:2003)]
ICS 91.060.50; 91.120.10
ISO/CEN PARALLEL PROCESSING
This draft has been developed within the International Organization for Standardization (ISO), and
processed under the ISO-lead mode of collaboration as defined in the Vienna Agreement.
This draft is hereby submitted to the ISO member bodies and to the CEN member bodies for a parallel
five-month enquiry.
Should this draft be accepted, a final draft, established on the basis of comments received, will be
submitted to a parallel two-month approval 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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.
©
International Organization for Standardization, 2009
---------------------- Page: 7 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
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 notice
This ISO document is a Draft International Standard and is copyright-protected by ISO. Except as permitted
under the applicable laws of the user's country, neither this ISO draft nor any extract from it may be
reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, photocopying,
recording or otherwise, without prior written permission being secured.
Requests for permission to reproduce should be addressed to 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
Reproduction may be subject to royalty payments or a licensing agreement.
Violators may be prosecuted.
©
ii ISO 2009 – All rights reserved
---------------------- Page: 8 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
Contents Page
1 Scope.1
2 Normative references.1
3 Terms, definitions, symbols and units.2
4 Calculation method .3
4.1 General principle .3
4.2 Validation of the calculation program.3
4.3 Determination of the thermal transmittance.3
5 Treatment of solid sections and boundaries.3
5.1 Solid materials .3
5.2 Boundaries.4
5.3 Roller shutter boxes.4
5.4 Extensions of window frame profiles.6
6 Treatment of cavities.6
6.1 General .6
6.2 Cavities in glazing .6
6.3 Unventilated air cavities in frames and roller shutter boxes.6
6.3.1 Definition .6
6.3.2 Unventilated rectangular cavities .7
6.3.3 Unventilated non-rectangular air cavities.10
6.4 Ventilated air cavities and grooves .11
6.4.1 Slightly ventilated cavities and grooves with small cross section .11
6.4.2 Well ventilated cavities and grooves with large cross section .12
7 Report.12
7.1 General .12
7.2 Geometrical data .12
7.3 Thermal data .13
7.3.1 Thermal conductivity .13
7.3.2 Emissivity.13
7.3.3 Boundary conditions.13
7.4 Results.13
Annex A (informative) Thermal conductivity of selected materials.14
Annex B (normative) Surface resistances.17
Annex C (normative) Determination of the thermal transmittance.19
C.1 Thermal transmittance of the frame section.19
C.2 Linear thermal transmittance of the junction with the glazing or opaque panel.20
Annex D (normative) Examples for the validation of the calculation programs .22
D.1 General.22
D.2 Figures.22
D.3 Results.32
© ISO 2009 – All rights reserved iii
---------------------- Page: 9 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
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 10077-2 was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in the
built environment, Subcommittee SC 2, Calculation methods, in cooperation with CEN/TC 89, Thermal
performance of buildings and building components.
This second edition cancels and replaces the first edition (ISO 10077-2:2003), which has been technically
revised.
ISO 10077 consists of the following parts, under the general title Thermal performance of windows, doors and
shutters — Calculation of thermal transmittance:
⎯ Part 1: General
⎯ Part 2: Numerical method for frames
iv © ISO 2009 – All rights reserved
---------------------- Page: 10 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
Introduction
ISO 10077 Thermal performance of windows, doors and shutters – Calculation of thermal transmittance
consists of two parts. The method in Part 2 Numerical method for frames is intended to provide calculated
values of the thermal characteristics of frame profiles, suitable to be used as input data in the calculation
method of the thermal transmittance of windows, doors and shutters given in Part 1 "General". It is an
alternative to the test method specified in EN 12412–2 (see Bibliography). In some cases, the hot box method
can be preferred, especially if physical and geometrical data are not available or if the profile is of complicated
geometrical shape.
Although the method in this Part 2 basically applies to vertical frame profiles, it is an acceptable approximation
for horizontal frame profiles (e.g. sill and head sections) and for products used in sloped positions (e.g. roof
windows). For calculations made with the glazing units in place, the heat flow pattern and the temperature
field within the frame are useful by-products of this calculation.
© ISO 2009 – All rights reserved v
---------------------- Page: 11 ----------------------
oSIST prEN ISO 10077-2:2009
---------------------- Page: 12 ----------------------
oSIST prEN ISO 10077-2:2009
DRAFT INTERNATIONAL STANDARD ISO/DIS 10077-2
Thermal performance of windows, doors and shutters —
Calculation of thermal transmittance — Part 2: Numerical
method for frames
1 Scope
This International Standard specifies a method and gives reference input data for the calculation of the
thermal transmittance of frame profiles and of the linear thermal transmittance of their junction with glazing or
opaque panels.
The method can also be used to evaluate the thermal resistance of shutter profiles and the thermal
characteristics of roller shutter boxes.
This standard also gives criteria for the validation of numerical methods used for the calculation.
This standard does not include effects of solar radiation, heat transfer caused by air leakage or three-
dimensional heat transfer such as pin point metallic connections. Thermal bridge effects between the frame
and the building structure are not included.
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.
EN 673, Glass in building — Calculation of thermal transmittance (U-value) — Calculation Method
EN 12519, Windows and pedestrian doors — Terminology
EN 13556, Round and sawn timber – Nomenclature of timbers used in Europe
ISO 6946, Building components and building elements — Thermal resistance and thermal transmittance —
Calculation method
ISO 7345, Thermal insulation — Physical quantities and definitions
ISO 10211, Thermal bridges in building construction — Heat flows and surface temperatures — Detailed
calculations
ISO 10456, Building materials and products — Hygrothermal properties — Tabulated design values and
procedures for determining declared and design thermal values
ISO 12567-2:2005, Thermal performance of windows and doors — Determination of thermal transmittance by
hot box method — Part 2: Roof windows and other projecting windows
ISO 17025, General requirements for the competence of testing and calibration laboratories
© ISO 2009 – All rights reserved 1
---------------------- Page: 13 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
3 Terms, definitions, symbols and units
For the purposes of this standard, the terms and definitions given in ISO 7345 and EN 12519 apply. Symbols
and units are listed in Table 1 and subscripts are listed in Table 2.
Table 1 — Symbols and units
Symbol Quantity Unit
2
A area
m
b width, i.e. perpendicular to the direction of heat flow m
d depth, i.e. parallel to the direction of heat flow m
E intersurface emittance –
F view factor –
2
h heat transfer coefficient
W/(m ·K)
2D
two-dimensional thermal conductance W/(m·K)
L
or thermal coupling coefficient
l length m
2
q density of heat flow rate
W/m
2
R thermal resistance
m ·K/W
T thermodynamic temperature K
2
U thermal transmittance
W/(m ·K)
2 4
Stefan-Boltzmann constant
σ W/(m ·K )
emissivity –
ε
thermal conductivity W/(m·K)
λ
linear thermal transmittance W/(m·K)
Ψ
Table 2 — Subscripts
a convective (surface to surface)
e external (outdoor)
g glazing
eq equivalent
f frame
i internal (indoor)
p panel
r radiative
s space (air or gas space)
sb shutter box
se external surface
si internal surface
2 © ISO 2009 – All rights reserved
---------------------- Page: 14 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
4 Calculation method
4.1 General principle
The calculation is carried out using a two-dimensional numerical method conforming to ISO 10211. The
elements shall be divided such that any further division does not change the calculated result significantly.
ISO 10211 gives criteria for judging whether sufficient sub-divisions have been used.
Vertical orientation of frame sections and air cavities is assumed for calculations by this standard for the
purposes of assigning equivalent thermal conductivity values (see 6.3); this applies irrespective of the
intended orientation of the actual window, including roof windows.
Normally the emissivity of surfaces bounding an air cavity shall have an emissivity of 0,9. Metallic surfaces
such as aluminium alloy frame, steel reinforcement and other metals/alloys may have a lower emissivity.
Typical values of the emissivity for metallic surfaces are given in Table A.3. Where values less then 0,9 are
used they shall be clearly stated with references in the report.
4.2 Validation of the calculation program
To ensure the suitability of the calculation program used, calculations shall be carried out on the examples
2D
described in Annex D. The calculated two-dimensional thermal conductance L shall not differ from the
corresponding values given in Table D.3 by more than ±3 %. This will lead to an accuracy of the thermal
transmittance, U, and the linear thermal transmittance Ψ, of about 5 %.
NOTE The ±deviations in Tables D.3 and D.4 are standard deviations from a Round Robin and are not to be
confused with ±3% specified above.
4.3 Determination of the thermal transmittance
The thermal transmittance of a frame section shall be determined with the glazing replaced by an insulating
panel according to Annex C, with the external and internal surface resistances taken from Annex B. The linear
thermal transmittance of the interaction of frame and glazing shall be determined from calculations with the
glazing in place and with the glazing replaced by an insulated panel.
The interaction of the frame and the building structure shall be considered as part of the linear thermal
transmittance of the installation section and not as part of the thermal transmittance of the frame section.
If materials (e.g. insulating material) are not permanently fixed and delivered with the frame or window these
materials are not part of the frame section.
NOTE In case of an overlap of the frame section and part of the wall the linear thermal transmittance could be
negative.
5 Treatment of solid sections and boundaries
5.1 Solid materials
For the purpose of this standard, thermal conductivity values used for solid materials shall be obtained
according to one of the following:
⎯ Table A.1 of this standard;
⎯ tabulated values given in ISO 10456;
© ISO 2009 – All rights reserved 3
---------------------- Page: 15 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
⎯ product standards;
⎯ technical approvals by a recognized national body;
⎯ measurements.
Measurements shall be used only if there is no tabulated data or data according to relevant product standards
or a technical approval. Measurements shall be performed at a mean temperature of 10 °C using the
appropriate method by an institute accredited (as specified in ISO 17025) to carry out those measurements.
To ensure that the thermal conductivity values are representative of the material (that is, that the value
incorporates likely variability of the material and the measurement uncertainty), one of the following methods
shall be used for obtaining the thermal conductivity value from measured data used in the calculations:
⎯ from measurements on at least on 3 different samples. The thermal conductivity is determined as the
mean value multiplied by 1,15;
⎯ the thermal conductivity is the declared value obtained from the measured data according to ISO 10456.
5.2 Boundaries
The external and internal surface resistances depend on the convective and radiative heat transfer to the
external and internal environment. If an external surface is not exposed to normal wind conditions the
convective part may be reduced in edges or junctions between two surfaces. The surface resistances for
horizontal heat flow are given in Annex B. These values shall be used for calculations by this standard
irrespective of the intended orientation of the actual window, including roof windows.
The cutting plane of the infill and the cutting plane to neighbouring material shall be taken as adiabatic (see
Figure 3 and Annex D).
The reference temperature conditions shall be 20 °C internal and 0 °C external.
5.3 Roller shutter boxes
Calculation of the thermal transmittance of a roller shutter box shall be done with the following boundary
conditions:
⎯ the top of the roller shutter box: adiabatic;
⎯ at the bottom of the roller shutter box where it adjoins the window frame: adiabatic for a distance of
60 mm;
2
·K/W;
⎯ surfaces adjacent to the internal environment: surface resistance of 0,13 m
2
⎯ surfaces adjacent to the external environment: surface resistance of 0,04 m ·K/W.
The cavity within the roller shutter box shall be treated as (see Figure 1):
⎯ if e + e ≤ 2 mm unventilated; the equivalent thermal conductivity of an unventilated air cavity is
1 3
calculated according to 6.3. Additional hardware like brushes, gaskets etc. can be taken into account for
;
determination of e and e
1 3
⎯ if e ≤ 35 mm, slightly ventilated, The equivalent thermal conductivity is twice that of an unventilated
tot
cavity of the same size;
⎯ if e > 35 mm, ventilated taking the air temperature within the cavity equal to the external air temperature
tot
2
but with a surface resistance of 0,13 m ·K/W.
4 © ISO 2009 – All rights reserved
---------------------- Page: 16 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
The relevant height of the roller shutter box, b , used for the calculation is the projected distance between the
sb
upper and lower adiabatic boundary (see Figure 1).
The assessment may be done with insulation on either or both of the boundaries B and C indicated in Figure 1.
If that is the case the thickness and thermal conductivity of the insulation shall be stated in the calculation
report.
Key
Boundaries (see Annex B):
A adiabatic boundary
B external surface resistance
C internal surface resistance
© ISO 2009 – All rights reserved 5
---------------------- Page: 17 ----------------------
oSIST prEN ISO 10077-2:2009
ISO/DIS 10077-2
NOTE The window frame (boundary A) is 60 mm wide but located with respect to the roller shutter box according to
the actual situation.
Figure 1 — Schematic example for the treatment of the boundaries for roller shutter boxes
5.4 Extensions of window frame profiles
For frames with special extensions overlapping the wall or other building elements, such as a Z-shaped profile,
the extensions shall be disregarded as illustrated in Figure 2. This applies to all profiles with special
extensions (e.g. H-shape) where the extensions overlap the wall or other building elements. Other boundaries
shall be treated as defined in Figure 3.
Figure 2 — Treatment of profiles with extensions (Z-shape)
6 Treatment of cavities
6.1 General
The heat flow rate in cavities shall be represented by an equivalent thermal conductivity λ . This equivalent
eq
thermal conductivity includes the heat flow by conduction, by convection and by radiation and depends on the
geometry of the cavity and on the adjacent materials.
6.2 Cavities in glazing
The equivalent thermal conductivity of an unventilated space between glass panes in glazing shall be
determined according to EN 673. The resulting equivalent conductivity shall be used in the whole cavity, up to
the edge.
NOTE The correlations for high aspect ratio cavities used in EN 673 tend to give low values for the equivalent
thermal conductivity. More accurate correlations are given in ISO 15099
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.