Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 1: General (ISO 10077-1:2006)

This part of ISO 10077 specifies methods for the calculation of the thermal transmittance of windows and pedestrian doors consisting of glazed and/or or opaque panels fitted in a frame, with and without shutters. This part of ISO 10077 allows for - different types of glazing (glass or plastic; single or multiple glazing; with or without low emissivity coatings, and with spaces filled with air or other gases); - opaque panels within the window or door; - various types of frames (wood, plastic, metallic with and without thermal barrier, metallic with pinpoint metallic connections or any combination of materials); - where appropriate, the additional thermal resistance introduced by different types of closed shutter, depending on their air permeability. The thermal transmittance of roof windows and other projecting windows can be calculated according to this part of ISO 10077, provided that the thermal transmittance of their frame sections is determined by measurement or by numerical calculation. Default values for glazing, frames and shutters are given in the informative annexes. Thermal bridge effects at the rebate or joint between the window or door frame and the rest of the building envelope are excluded from the calculation. The calculation does not include - effects of solarradiation, - heat transfer caused by air leakage, - calculation of condensation, - ventilation of air spaces in double and coupled windows, - surrounding parts of an oriel window. The part of ISO 10077 does not apply to - curtain walls and other structural glazing, - industrial, commercial and garage doors.

Wärmetechnisches Verhalten von Fenstern, Türen und Abschlüssen - Berechnung des Wärmedurchgangskoeffizienten - Teil 1: Allgemeines (ISO 10077-1:2006)

Dieser Teil von ISO 10077 legt Verfahren zur Ermittlung des Wärmedurchgangskoeffizienten von Fenstern und Türen fest, die aus einer Verglasung und/oder opaken Füllungen in einem Rahmen mit oder ohne Abschlüsse bestehen.
Dieser Teil von ISO 10077 berücksichtigt:
-   unterschiedliche Verglasungsarten (Glas oder Kunststoff, Einfachverglasung oder Mehrfachver-glasungen; mit oder ohne Beschichtungen mit geringem Emissionsgrad; mit Luft- oder anderen Gasfüllungen im Zwischenraum);
-   opake Füllungen im Fenster bzw. in der Tür;
-   unterschiedliche Rahmenarten (Holz, Kunststoff, Metall mit und ohne Wärmedämmung; Metallrahmen mit metallischen Verbindungen, wie Stifte usw., oder jede andere Kombination von Werkstoffen);
-   sofern anwendbar, den zusätzlichen Wärmedurchlasswiderstand, der durch verschiedene Arten von geschlossenen Abschlüssen in Abhängigkeit von ihrer Luftdurchlässigkeit bewirkt wird.
Der Wärmedurchgangskoeffizient von Dachfenstern und anderen vorstehenden Fenstern kann mit Hilfe dieses Teils von ISO 10077 berechnet werden, sofern der Wärmedurchgangskoeffizient ihrer Rahmenabschlüsse durch Messungen oder numerische Berechnung bestimmt wird.
In informativen Anhängen sind Standardwerte für Verglasungen, Rahmen und Abschlüsse angegeben. Die Wirkung von Wärmebrücken im Bereich der Leibung oder des Baukörperanschlusses und der übrigen Gebäudehülle sind von der Berechnung ausgenommen.
Die Berechnung berücksichtigt nicht:
-   Einflüsse aus der Sonneneinstrahlung;
-   Wärmeübertragung infolge Luftdurchlässigkeit;
-   das Tauverhalten;
-   belüftete Zwischenräume in Kastenfenstern und Verbundfenstern;
-   Umrahmung von Erkerfenstern.
Dieser Teil von ISO 10077 gilt nicht für
-   Vorhangfassaden und andere tragende Verglasungen;
-   Tore.

Performance thermique des fenetres, portes et fermetures - Calcul du coefficient de transmission thermique - Partie 1: Généralités (ISO 10077-1:2006)

L'ISO 10077-1:2006 spécifie des méthodes de calcul du coefficient de transmission thermique des fenêtres et des portes pour piétons constituées de panneaux vitrés et/ou opaques montés dans un cadre, avec ou sans fermetures.
L'ISO 10077-1:2006 prend en compte:
les différents types de vitrage (en verre ou en plastique; simples ou multiples; avec ou sans revêtements peu émissifs; avec espaces intercalaires remplis d'air ou d'autres gaz);
les panneaux opaques à l'intérieur de la fenêtre ou de la porte;
les différents types d'encadrements (en bois; en plastique; en métal avec ou sans coupure thermique; en métal avec jonctions métalliques ponctuelles ou toute combinaison de matériaux);
le cas échéant, la résistance thermique supplémentaire introduite par différents types de fermetures extérieures, en fonction de leur perméabilité à l'air.
Le coefficient de transmission thermique des fenêtres de toit et des autres fenêtres à projection peut être calculé selon l'ISO 10077-1:2006, à condition que le coefficient de transmission thermique de leurs encadrements soit déterminé par mesure ou par calcul numérique.
Des valeurs par défaut pour les vitrages, encadrements et fermetures sont données dans les annexes informatives. Les effets de pont thermique à la contrefeuillure ou au joint entre l'encadrement de fenêtre ou de porte et le reste de l'enveloppe du bâtiment sont exclus du calcul.
Le calcul n'inclut pas:
les effets du rayonnement solaire;
les transferts de chaleur dus aux infiltrations d'air;
le calcul des condensations;
la ventilation des lames d'air dans les fenêtres doubles et à vantaux dédoublés;
les parties environnantes d'un oriel.
L'ISO 10077-1:2006 ne s'applique pas aux:
façades légères et aux autres vitrages structurels;
portes industrielles, commerciales et portes de garage.

Toplotne lastnosti oken, vrat in polken - Izračun toplotne prehodnosti - 1. del: Splošno (ISO 10077-1:2006)

Ta del ISO 10077 določa metode za izračun toplotne prehodnosti oken in zunanjih vhodnih vrat, sestavljenih iz zastekljenih in/ali neprosojnih plošč, nameščenih v okvir, s polkni ali brez. Ta del ISO 10077 dovoljuje – različne vrste zasteklitve (s steklom ali plastiko; enojno ali večkratno; s toplotno zaščitnimi nanosi ali brez in s prostorom, napolnjenim z zrakom ali drugimi plini); - neprosojne plošče v oknih ali vratih; - različne vrste okvirov (lesene, polimerne, kovinske s toplotnimi pregradami ali brez, kovinske z natančnimi kovinskimi priključki ali iz katere koli kombinacije materialov); - po potrebi dodatno toplotno odpornost, ki jo omogočajo raznovrstna zaprta polkna, odvisno od prepustnosti zraka. Toplotna prehodnost strešnih oken in drugih izbočenih oken se lahko izračuna v skladu s tem delom ISO 10077, pod pogojem, da se toplotna prehodnost prerezov okvirjev določi z merjenjem ali numeričnim izračunom. Privzete vrednosti za zasteklitev, okvire in polkna so podane v informativnih dodatkih. Izračun ne vključuje učinkov toplotnih mostov pri utoru ali spoju med okenskim ali vratnim okvirjem ter ostalim toplotnim ovojem stavbe. Izračun ne vključuje – učinkov sončnega sevanja, - prenosa toplota, ki ga povzroča uhajanje zraka, - izračuna kondenzacije, - prezračevanja zračnih prostorov v dvojnih in sklopljenih oknih, - sosednjih delov pomolnega okna. Ta del ISO 10077 ne velja za – zunanje stene in druge steklene fasade, - vrata v industrijske in javne prostore ter garažna vrata.

General Information

Status
Withdrawn
Publication Date
31-Jan-2007
Withdrawal Date
10-Aug-2017
Technical Committee
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
11-Aug-2017
Due Date
03-Sep-2017
Completion Date
11-Aug-2017

Relations

Buy Standard

Standard
EN ISO 10077-1:2007
English language
42 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 10077-1:2007
01-februar-2007
7RSORWQHODVWQRVWLRNHQYUDWLQSRONHQ,]UDþXQWRSORWQHSUHKRGQRVWLGHO
6SORãQR ,62
Thermal performance of windows, doors and shutters - Calculation of thermal
transmittance - Part 1: General (ISO 10077-1:2006)
Wärmetechnisches Verhalten von Fenstern, Türen und Abschlüssen - Berechnung des
Wärmedurchgangskoeffizienten - Teil 1: Allgemeines (ISO 10077-1:2006)
Performance thermique des fenetres, portes et fermetures - Calcul du coefficient de
transmission thermique - Partie 1: Généralités (ISO 10077-1:2006)
Ta slovenski standard je istoveten z: EN ISO 10077-1:2006
ICS:
91.060.50 Vrata in okna Doors and windows
91.120.10 Toplotna izolacija stavb Thermal insulation
SIST EN ISO 10077-1:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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

EUROPEAN STANDARD
EN ISO 10077-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2006
ICS 91.120.10; 91.060.50 Supersedes EN ISO 10077-1:2000
English Version
Thermal performance of windows, doors and shutters -
Calculation of thermal transmittance - Part 1: General (ISO
10077-1:2006)
Performance thermique des fenêtres, portes et fermetures - Wärmetechnisches Verhalten von Fenstern, Türen und
Calcul du coefficient de transmission thermique - Partie 1: Abschlüssen - Berechnung des
Généralités (ISO 10077-1:2006) Wärmedurchgangskoeffizienten - Teil 1: Allgemeines (ISO
10077-1:2006)
This European Standard was approved by CEN on 2 August 2006.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10077-1:2006: E
worldwide for CEN national Members.

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

EN ISO 10077-1:2006 (E)





Foreword


This document (EN ISO 10077-1:2006) has been prepared by Technical Committee ISO/TC 163
"Thermal insulation" in collaboration with Technical Committee CEN/TC 89 "Thermal
performance of buildings and building components", the secretariat of which is held by SIS.

This 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 March 2007, and conflicting national
standards shall be withdrawn at the latest by March 2007.

This document supersedes EN ISO 10077-1:2000.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
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.


Endorsement notice

The text of ISO 10077-1:2006 has been approved by CEN as EN ISO 10077-1:2006 without any
modifications.

2

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

INTERNATIONAL ISO
STANDARD 10077-1
Second edition
2006-09-15


Thermal performance of windows, doors
and shutters — Calculation of thermal
transmittance —
Part 1:
General
Performance thermique des fenêtres, portes et fermetures — Calcul du
coefficient de transmission thermique —
Partie 1: Généralités




Reference number
ISO 10077-1:2006(E)
©
ISO 2006

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

ISO 10077-1:2006(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.


©  ISO 2006
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 2006 – All rights reserved

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

ISO 10077-1:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 2
3 Terms, definitions, symbols and units . 2
3.1 Terms and definitions. 2
3.2 Symbols and units. 3
3.3 Subscripts . 3
4 Geometrical characteristics. 3
4.1 Glazed area, opaque panel area . 3
4.2 Total visible perimeter of the glazing . 3
4.3 Frame areas. 4
4.4 Window area. 4
5 Calculation of thermal transmittance . 6
5.1 Windows . 6
5.2 Glazing . 9
5.3 Windows with closed shutters . 10
5.4 Doors. 11
6 Input data. 13
7 Report . 13
7.1 Contents of report. 13
7.2 Drawing of sections. 13
7.3 Drawing of the whole window or door. 14
7.4 Values used in the calculation . 14
7.5 Presentation of results. 14
Annex A (normative) Internal and external surface thermal resistances. 15
Annex B (normative) Thermal conductivity of glass . 16
Annex C (informative) Thermal resistance of air spaces between glazing and thermal
transmittance of coupled, double or triple glazing . 17
Annex D (informative) Thermal transmittance of frames . 19
Annex E (normative) Linear thermal transmittance of frame/glazing junction. 25
Annex F (informative) Thermal transmittance of windows . 27
Annex G (informative) Additional thermal resistance for windows with closed shutters . 32
Annex H (informative) Permeability of shutters . 33
Bibliography . 35

© ISO 2006 – All rights reserved iii

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

ISO 10077-1:2006(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 10077-1 was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in the
built environment, Subcommittee SC 2, Calculation methods.
This second edition cancels and replaces the first edition (ISO 10077-1:2000), the following clauses and
subclauses of which have been technically revised.
Clause Changes
Introduction Added new paragraph explaining the various parts of the overall thermal transmittance
1 Amended 4th paragraph to permit calculation of U-value of roof windows
2 References to ISO rather than EN ISO where applicable
4.3 Added “including sashes if present” to the definition of areas
4.4 Clarification that sealing gaskets are ignored in the determination of areas. Dimensions
to be measured to nearest mm.
5.1.1 Third from last paragraph inserted concerning roof windows
5.3 Data on shutters moved to Annex G
6 Added paragraph to say that declared values are to be obtained for horizontal heat flow
(as in ISO 10292 and EN 673)
7.1 Second dash, drawing to give details also for metal frames
Table A.1 Added surface resistance values for horizontal or inclined window
Annex E Complete revision of Annex E. It has been changed to normative, because it provides
default values that are to be used in the absence of detailed values.
Annex F Complete revision of Annex F, using the new values in Annex E
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 2006 – All rights reserved

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

ISO 10077-1:2006(E)
Introduction
The calculation method described in this part of ISO 10077 is used to evaluate the thermal transmittance of
windows and doors, or as part of the determination of the energy use of a building.
An alternative to calculation is testing of the complete window or door according to ISO 12567-1 or, for roof
windows, according to ISO 12567-2.
The calculation is based on four component parts of the overall thermal transmittance:
⎯ for elements containing glazing, the thermal transmittance of the glazing, calculated using EN 673 or
measured according to EN 674 or EN 675;
⎯ for elements containing opaque panels, the thermal transmittance of the opaque panels, calculated
according to ISO 6946 and/or ISO 10211 (all parts) or measured according to ISO 8301 or ISO 8202;
⎯ thermal transmittance of the frame, calculated using ISO 10077-2, measured according to EN 12412-2, or
taken from Annex D of this part of ISO 10077;
⎯ linear thermal transmittance of the frame/glazing junction, calculated according to ISO 10077-2 or taken
from Annex E of this part of ISO 10077.
More detailed equations for calculation of heat flow through windows can be found in ISO 15099.
The thermal transmittance of curtain walling can be calculated using prEN 13947.
EN 13241-1 gives procedures applicable to doors intended to provide access for goods and vehicles.
© ISO 2006 – All rights reserved v

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

INTERNATIONAL STANDARD ISO 10077-1:2006(E)

Thermal performance of windows, doors and shutters —
Calculation of thermal transmittance —
Part 1:
General
1 Scope
This part of ISO 10077 specifies methods for the calculation of the thermal transmittance of windows and
pedestrian doors consisting of glazed and/or or opaque panels fitted in a frame, with and without shutters.
This part of ISO 10077 allows for
⎯ different types of glazing (glass or plastic; single or multiple glazing; with or without low emissivity
coatings, and with spaces filled with air or other gases);
⎯ opaque panels within the window or door;
⎯ various types of frames (wood, plastic, metallic with and without thermal barrier, metallic with pinpoint
metallic connections or any combination of materials);
⎯ where appropriate, the additional thermal resistance introduced by different types of closed shutter,
depending on their air permeability.
The thermal transmittance of roof windows and other projecting windows can be calculated according to this
part of ISO 10077, provided that the thermal transmittance of their frame sections is determined by
measurement or by numerical calculation.
Default values for glazing, frames and shutters are given in the informative annexes. Thermal bridge effects at
the rebate or joint between the window or door frame and the rest of the building envelope are excluded from
the calculation.
The calculation does not include
⎯ effects of solar radiation,
⎯ heat transfer caused by air leakage,
⎯ calculation of condensation,
⎯ ventilation of air spaces in double and coupled windows,
⎯ surrounding parts of an oriel window.
The part of ISO 10077 does not apply to
⎯ curtain walls and other structural glazing,
⎯ industrial, commercial and garage doors.
© ISO 2006 – All rights reserved 1

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

ISO 10077-1:2006(E)
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 6946, Building components and building elements — Thermal resistance and thermal transmittance —
Calculation method
ISO 7345, Thermal insulation — Physical quantities and definitions
ISO 8301, Thermal insulation — Determination of steady-state thermal resistance and related properties —
Heat flow meter apparatus
ISO 8302, Thermal insulation — Determination of steady-state thermal resistance and related properties —
Guarded hot plate apparatus
ISO 10077-2, Thermal performance of windows, doors and shutters — Calculation of thermal transmittance —
Part 2: Numerical method for frames
ISO 10211 (all parts), Thermal bridges in building construction — Heat flows and surface temperatures —
Detailed calculations
ISO 12567-2, Thermal performance of windows and doors — Determination of thermal transmittance by hot
box method — Part 2: Roof windows and other projecting windows
EN 673, Glass in building — Determination of thermal transmittance (U value) — Calculation method
EN 674, Glass in building — Determination of thermal transmittance (U value) — Guarded hot plate method
EN 675, Glass in building — Determination of thermal transmittance (U value) — Heat flow meter method
EN 12412-2, Thermal performance of windows, doors and shutters — Determination of thermal transmittance
by hot box method — Part 2: Frames
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 673 and ISO 7345 apply.
In Clause 4 of this part of ISO 10077, descriptions are given of a number of geometrical characteristics of
glazing and frame.
2 © ISO 2006 – All rights reserved

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

ISO 10077-1:2006(E)
3.2 Symbols and units
Symbol Quantity Unit
2
A area m
2
R thermal resistance m⋅K/W
2
U thermal transmittance W/(m⋅K)
b width m
d distance, thickness m
l length m
2
q density of heat flow rate W/m
Ψ linear thermal transmittance W/(m⋅K)
λ thermal conductivity W/(m⋅K)
3.3 Subscripts
D door i internal
W window j summation index
WS window with closed shutter p panel (opaque)
d developed s space (air or gas space)
e external se external surface
f frame sh shutter
g glazing si internal surface
4 Geometrical characteristics
4.1 Glazed area, opaque panel area
The glazed area, A , or the opaque panel area, A , of a window or door is the smaller of the visible areas seen
g p
from both sides; see Figure 1. Any overlapping of gaskets is ignored.
4.2 Total visible perimeter of the glazing
The total perimeter of the glazing, l , (or the opaque panel, l ) is the sum of the visible perimeter of the glass
g p
panes (or opaque panels) in the window or door. If the perimeters are different on either side of the pane or
panel, then the larger of the two shall be used; see Figure 1.

Key
1 glass
Figure 1 — Illustration of glazed area and perimeter
© ISO 2006 – All rights reserved 3

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

ISO 10077-1:2006(E)
4.3 Frame areas
For the definition of the areas, see also Figure 3.
A Internal projected frame area:
f,i
The internal projected frame area is the area of the projection of the internal frame, including sashes if
present, on a plane parallel to the glazing panel.
A External projected frame area:
f,e
The external projected frame area is the area of the projection of the external frame, including sashes if
present, on a plane parallel to the glazing panel.
A Frame area:
f
The frame area is the larger of the two projected areas seen from both sides.
A Internal developed frame area:
f,di
The internal developed frame area is the area of the frame, including sashes if present, in contact with
the internal air (see Figure 2).
A External developed frame area:
f,de
The external developed frame area is the area of the frame, including sashes if present, in contact with
the external air (see Figure 2).

Key
1 frame
2 glazing
a
Internal.
b
External.
Figure 2 — Internal and external developed area
4.4 Window area
The window area, A , is the sum of the frame area, A , and the glazing area, A , (or the panel area, A ).
w f g p
The frame area and the glazed area are defined by the edge of the frame, i.e. sealing gaskets are ignored for
the purposes of determination of the areas.
Window dimensions (height, width, frame width and frame thickness) shall be determined to the nearest
millimetre.
4 © ISO 2006 – All rights reserved

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

ISO 10077-1:2006(E)

Key
1 sash (moveable)
2 frame (fixed)
a
Internal.
b
External.
A = max (A ; A )
f f,i f,e
A = A + A
w f
g
A = A + A + A + A
f,di 1 2 3 4
A = A + A + A + A
f,de 5 6 7 8
NOTE 1 The frame area, A , includes the area of the fixed frame together with that of any moveable sash or casement.
f
NOTE 2 Drip trays and similar protuberances are not considered as parts of the developed area.
Figure 3 — Illustration of the various areas
© ISO 2006 – All rights reserved 5

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

ISO 10077-1:2006(E)
5 Calculation of thermal transmittance
5.1 Windows
5.1.1 Single windows

Key
1 frame (fixed)
2 sash (moveable)
3 glazing (single or multiple)
Figure 4 — Illustration of single window
The thermal transmittance of a single window, U , shall be calculated using Equation (1):
W
AU++A U l Ψ
∑∑gg f f∑ g g
U = (1)
W
AA+
∑∑gf
where
U is the thermal transmittance of the glazing;
g
U is the thermal transmittance of the frame;
f
Ψ is the linear thermal transmittance due to the combined thermal effects of glazing, spacer and frame;
g
and the other symbols are defined in Clause 4. The summations included in Equation (1) are used to allow for
different parts of the glazing or frame, e.g. several values of A are needed when different values of U apply to
f f
the sill, head, jambs and dividers.
In the case of single glazing the last term of the numerator in Equation (1) shall be taken as zero (no spacer
effect) because any correction is negligible.
When there are both opaque panels and glazed panes, U , is calculated using Equation (2):
W
AU++AU A U+ l Ψ+ l Ψ
∑∑gg pp∑ f f∑ g g∑ p p
U = (2)
W
AA++A
∑∑gp∑f
where
U is the thermal transmittance of the opaque panel(s);
p
Ψ is the linear thermal transmittance for the opaque panel(s).
p
6 © ISO 2006 – All rights reserved

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

ISO 10077-1:2006(E)
Ψ may be taken as zero if
p
⎯ the internal and external facings of the panel are of material with thermal conductivity less than
0,5 W/(m⋅K), and
⎯ the thermal conductivity of any bridging material at the edges of the panel is less than 0,5 W/(m⋅K).
In other cases, Ψ shall be calculated in accordance with ISO 10077-2.
p
U shall be obtained in accordance with 5.2.
g
U for roof windows shall be either
f
⎯ calculated in accordance with ISO 10077-2, or
⎯ measured in accordance with EN 12412-2 with specimens mounted within the aperture in the surround
panel flush with the cold side, in accordance with in ISO 12567-2.
For other windows, U shall be
f
⎯ calculated in accordance with ISO 10077-2, or
⎯ measured in accordance with EN 12412-2, or
⎯ obtained from Annex D.
Linear thermal transmittance may be calculated in accordance with ISO 10077-2 or taken from Annex E.
5.1.2 Double windows
Dimensions in millimetres

Key
1 frame (fixed)
2 sash (moveable)
3 glazing (single or multiple)
a
Internal.
b
External.
Figure 5 — Illustration of double window
© ISO 2006 – All rights reserved 7

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

ISO 10077-1:2006(E)
The thermal transmittance, U , of a system consisting of two separate windows shall be calculated using
W
Equation (3).
1
U = (3)
W
1/UR−+R−R+ 1/U
WW1si s se 2
where
U , U are the thermal transmittances of the external and internal window, respectively, calculated
W1 W2
according to Equation (1);
R is the internal surface resistance of the external window when used alone;
si
R is the external surface resistance of the internal window when used alone;
se
R is the thermal resistance of the space between the glazing in the two windows.
s
NOTE Typical values of R and R are given in Annex A and of R , in Annex C.
si se s
If either of the gaps shown in Figure 5 exceeds 3 mm and measures have not been taken to prevent
excessive air exchange with external air, the method does not apply.
5.1.3 Coupled windows
Dimensions in millimetres

Key
1 glazing (single or multiple)
a
Internal.
b
External.
Figure 6 — Illustration of coupled windows
The thermal transmittance, U , of a system consisting of one frame and two separate sashes or casements
W
shall be calculated using Equation (1). To determine the thermal transmittance, U , of the combined glazing
g
Equation (4) shall be used:
1
U = (4)
g
11//UR−+R−R+U
g1 si s se g2
where
U , U are the thermal transmittances of the external and internal glazing; respectively, calculated in
g1 g2
accordance with Equations (5) and (6);
8 © ISO 2006 – All rights reserved

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

ISO 10077-1:2006(E)
R is the internal surface resistance of the external glazing when used alone;
si
R is the external surface resistance of the internal glazing when used alone;
se
R is the thermal resistance of the space between the internal and external glazing.
s
NOTE Typical values of R and R are given in Annex A and of R , in Annex C.
si se s
If the gap exceeds 3 mm and measures have not been taken to prevent excessive air exchange with external
air, the method does not apply.
5.2 Glazing
5.2.1 Single glazing
The thermal transmittance of the single and laminated glazing, U , shall be calculated using Equation (5).
g
1
U = (5)
g
d
j
R++ R
se ∑ si
λ
j
j
where
R is the external surface resistance;
se
λ is the thermal conductivity of glass or material layer j;
j
d is the thickness of the glass pane or material layer j;
j
R is the internal surface resistance.
si
NOTE Typical values of R and R are given in Annex A.
se si
5.2.2 Multiple glazing
The thermal transmittance of multiple glazing, U , can be calculated in accordance with EN 673 or by means
g
of Equation (6):
1
U = (6)
g
d
j
R++ R R+
se∑∑ s,j si
λ
j
jj
where
R is the external surface resistance;
se
λ is the thermal conductivity of glass or material layer j;
j
d is the thickness of the glass pane or material layers j;
j
R is the internal surface resistance;
si
R is the thermal resistance of air space j.
j
s,
NOTE Typical values of R are given in Annex C.
s
© ISO 2006 – All rights reserved 9

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

ISO 10077-1:2006(E)
5.3 Windows with closed shutters
A shutter on the outside of a window introduces an additional thermal resistance, resulting from both the air
layer enclosed between the shutter and the window, and the shutter itself (see Figure 7). The thermal
transmittance of a window with closed shutters, U , is given by Equation (7):
WS
1
U = (7)
WS
1/UR+∆
W
where
U is the thermal transmittance of the window;
W
∆R is the additional thermal resistance due to the air layer enclosed between the shutter and the
window and the closed shutter itself (see Figure 7).

Key
1 shutter
a
Internal.
b
External.
Figure 7 — Window with external shutter
∆R depends on the thermal transmission properties of the shutter and on its air permeability. Further
information is given in Annex G.
10 © ISO 2006 – All rights reserved

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

ISO 10077-1:2006(E)
5.4 Doors
5.4.1 Fully glazed doors

Key
1 frame (fixed)
2 sash (moveable)
3 glazing (single or multiple)
Figure 8 — Illustration of door with glazing
The thermal transmittance, U , of a door se
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.