ISO 10077-2:2003

Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 2: Numerical method for frames

ISO 10077-2:2003 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. ISO 10077-2:2003 also gives criteria for the validation of numerical methods used for the calculation. ISO 10077-2:2003 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.

Performance thermique des fenêtres, portes et fermetures — Calcul du coefficient de transmission thermique — Partie 2: Méthode numérique pour les encadrements

General Information

• Status: Withdrawn
• Publication Date: 09-Oct-2003
• Withdrawal Date: 09-Oct-2003
• ICS: 91.060.50 - Doors and windows
• ICS: 91.120.10 - Thermal insulation of buildings
• Technical Committee: ISO/TC 163 - Thermal performance and energy use in the built environment
• Drafting Committee: ISO/TC 163 - Thermal performance and energy use in the built environment
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 22-Feb-2012

Relations

• Revised: ISO 10077-2:2012 - Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 2: Numerical method for frames
• Effective Date: 12-May-2008
• Consolidates: ISO 2909:1975 - Title missing - Legacy paper document
• Effective Date: 28-Feb-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 10077-2
First edition
2003-10-01

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 10077-2:2003(E)
©
ISO 2003

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ISO 10077-2:2003(E)
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ii © ISO 2003 – All rights reserved

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ISO 10077-2:2003(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 the European Committee for Standardization (CEN) in collaboration with
Technical Committee ISO/TC 163, Thermal performance and energy use in the built environment, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Throughout the text of this document, read ".this European Standard." to mean ".this International
Standard.".
ISO 10077 consists of the following parts, under the general title Thermal performance of windows, doors and
shutters — Calculation of thermal transmittance:
— Part 1: Simplified method
— Part 2: Numerical method for frames

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ISO 10077-2:2003(E)

Contents
Page
Foreword.v
Introduction .vi
1 Scope .1
2 Normative references .1
3 Terms, definitions, symbols and units .2
4 Calculation method.2
4.1 General principle.2
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 .3
6 Treatment of cavities .3
6.1 General.3
6.2 Cavities in glazing.3
6.3 Unventilated air cavities in frames.3
6.3.1 Definition.3
6.3.2 Unventilated rectangular cavities.4
6.3.3 Unventilated non-rectangular air cavities .6
6.4 Ventilated air cavities and grooves.7
6.4.1 Slightly ventilated cavities and grooves with small cross section.7
6.4.2 Well ventilated cavities and grooves with large cross section.7
7 Report.8
7.1 General.8
7.2 Geometrical data.8
7.3 Thermal data.8
7.3.1 Thermal conductivity.8
7.3.2 Emissivity .8
7.3.3 Boundary conditions .8
7.4 Results .8
Annex A (informative) Design thermal conductivity of selected materials .9
Annex B (normative) Surface resistances for horizontal heat flow .11
Annex C (normative) Determination of the thermal transmittance .12
C.1 Thermal transmittance of the frame section.12
C.2 Linear thermal transmittance of the junction with the glazing or opaque panel .13
Annex D (normative) Examples for the validation of the calculation programs.14
D.1 General.14
D.2 Figures .14
D.3 Results .24
Annex ZA (normative) Normative references to international publications with their corresponding
European publications .25
Bibliography .26
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ISO 10077-2:2003(E)


Foreword
This document EN ISO 10077-2:2003 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 April 2004, and conflicting national standards shall be withdrawn at the latest by
April 2004.
This standard is one of a series of standards on calculation methods for the design and evaluation of the thermal
performance of buildings and building components.
Annexes B, C, D and ZA are normative.
Annexes A and ZB are informative.
This document includes a Bibliography.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,
Slovakia, Spain, Sweden, Switzerland and the United Kingdom.
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ISO 10077-2:2003(E)


Introduction
The series of EN 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 simplified
calculation method of the thermal transmittance of windows, doors and shutters given in Part 1: "Simplified method.
It is an alternative to the test method specified in prEN 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).
The heat flow pattern and the temperature field within the frame are useful by-products of this calculation.
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ISO 10077-2:2003(E)
1 Scope
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.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
prEN 12519:1996, Windows and doors – Terminology.
EN ISO 7345:1995, Thermal insulation – Physical quantities and definitions (ISO 7345:1987).
EN ISO 10211-1:1995, Thermal bridges in building construction – Heat flows and surface temperatures – Part 1:
General calculation methods (ISO 10211-1:1995).
ISO 10292, Glass in building - Calculation of steady-state U values (thermal transmittance) of multiple glazing.
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ISO 10077-2:2003(E)
3 Terms, definitions, symbols and units
For the purposes of this European Standard, the terms and definitions given in EN ISO 7345:1995 and
prEN 12519:1996 apply.
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
L two-dimensional thermal conductance W/(m·K)
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
sStefan-Boltzmann constant W/(m ⋅K )
eemissivity –
lthermal conductivity W/(m⋅K)
Ylinear thermal transmittance W/(m⋅K)
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
4 Calculation method
4.1 General principle
The calculation is carried out using a two-dimensional numerical method conforming to EN ISO 10211-1. The
elements shall be divided such that any further division does not change the calculated result significantly.
EN ISO 10211-1 gives criteria for judging whether sufficient sub-divisions have been used.
It is assumed that the principal heat flow in the section is perpendicular to a plane parallel to the external and
internal surfaces. Vertical orientation of sections and air cavities is assumed. It is assumed that the emissivity of the
surfaces adjoining the air cavities is 0,9 (it is assumed that the normal emissivity is 0,85). If other values are used
they shall be clearly stated with references in the report.
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ISO 10077-2:2003(E)
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 Y, of about 5 %.
4.3 Determination of the thermal transmittance
The thermal transmittance of a frame section and the linear thermal transmittance of the interaction of frame and
glazing 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.
5 Treatment of solid sections and boundaries
5.1 Solid materials
Design values of thermal conductivity for common materials are given in annex A. Design values derived from
measurements may be used instead of those in annex A, but this shall be clearly stated in the report. Further
values can be obtained from EN 12524.
NOTE Design values derived in accordance with ISO 10456 (see Bibliography) is an alternative.
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 (see EN ISO 10211-1:1995, annex E). The surface
resistances for horizontal heat flow are given in annex B. The cutting plane of the infill and the cutting plane to
neighbouring material shall be taken as adiabatic (see Figure 1).
For the calculation of condensation risk see EN ISO 10211-1.
6 Treatment of cavities
6.1 General
The heat flow rate in cavities shall be represented by an equivalent thermal conductivity l. 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 ISO 10292. 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 and ISO 10292 tend to give low values for the
equivalent thermal conductivity. More accurate correlations are given in ISO 15099 (see Bibliography).
6.3 Unventilated air cavities in frames
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 1). Otherwise the cavity shall be treated as ventilated.
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ISO 10077-2:2003(E)
Dimensions in millimetres
Key
Boundaries (see annex B): Cavities and grooves:
A Adiabatic boundary E Glazing (see 6.2)
B External surface resistance F Unventilated cavity (see 6.3)
C Internal surface resistance G Sli
...