EN 1279-3:2018

Glass in building - Insulating glass units - Part 3: Long term test method and requirements for gas leakage rate and for gas concentration tolerances

This European Standard describes the test method for the determination of gas leakage rate and specifies the requirements for limit values for gas leakage rate and gas concentration for gas filled insulating glass units made
a)   in accordance with EN 1279 1:2018 and manufactured to EN 1279 6:2018, or
b)   for the purpose to demonstrate that components (e.g. edge seals or spacers) will allow the insulating glass unit to conform to the requirements given in EN 1279 1:2018, Clause 6.

Glas im Bauwesen - Mehrscheiben-Isolierglas - Teil 3: Langzeitprüfverfahren und Anforderungen bezüglich Gasverlustrate und Grenzabweichungen für die Gaskonzentration

Die vorliegende Europäische Norm beschreibt das Prüfverfahren für die Bestimmung der Gasverlustrate und legt die Anforderungen an die Grenzwerte für die Gasverlustrate und die Gaskonzentration von gasgefülltem Mehrscheiben Isolierglas fest, dass
a)   in Übereinstimmung mit EN 1279 1:2018 und EN 1279 6:2018 gefertigt wurde oder
b)   gefertigt wurde, um zu zeigen, dass die Komponenten (z. B. Randverbund oder Abstandhalter) es zulassen, dass das Mehrscheiben Isolierglas mit den Anforderungen in EN 1279 1:2018, Abschnitt 6, übereinstimmt.

Verre dans la construction - Vitrage isolant - Partie 3 : Méthode d'essai à long terme pour le débit de fuite et prescriptions pour les tolérances de concentration en gaz

Le présent document décrit la méthode d'essai pour la détermination du débit de fuite de gaz et spécifie les prescriptions relatives aux valeurs limites du débit de fuite de gaz et de concentration du gaz pour les vitrages isolants produits
a)   conformément à l’EN 1279-1:2018 et fabriquées conformément à l’EN 1279-6:2018 ; ou
b)   dans le but de démontrer que des composants (par exemple, mastics ou espaceurs) permettront au vitrage isolant d'être conformes aux exigences de l’EN 1279-1:2018, Article 6.

Steklo v gradbeništvu - Izolacijsko steklo - 3. del: Dolgoročna preskusna metoda ter zahteve za stopnjo uhajanja plina in tolerance koncentracije plina

Ta evropski standard opisuje preskusno metodo za ugotavljanje stopnje uhajanja plina in določa zahteve za mejne vrednosti stopnje uhajanja plina in koncentracije plina za izolacijsko steklo, napolnjeno s plinom, izdelano
a) v skladu s standardom prEN 1279-1:2015 in prEN 1279-6:2015 ali
b) za dokazovanje, da komponente (npr. robna tesnila ali distančniki) steklu omogočajo skladnost z zahtevami, opredeljenimi v točki 6 standarda prEN 1279-1:2015.

General Information

• Status: Published
• Publication Date: 24-Jul-2018
• Withdrawal Date: 30-Jan-2019
• ICS: 81.040.20 - Glass in building
• Technical Committee: CEN/TC 129 - Glass in building
• Drafting Committee: CEN/TC 129/WG 4 - Insulating glass units
• Current Stage: 9092 - Decision on results of review/2YR ENQ - revise - Review Enquiry
• Start Date: 13-Mar-2025
• Completion Date: 14-Apr-2025
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive: 88/609/EEC - Limitation of emissions of certain pollutants into the air from large combustion plants
• Mandate: M/135 - Mandate to CEN/CENELEC concerning the execution of standardization work for harmonized standards on flat glass, profiled glass and glass block products
• Mandate: M/135_AM1 - First amendment to mandate M/135 - Mandate to CEN/CENELEC concerning the execution of standardisation work for harmonised standards on glass
• Ref Project: SIST EN 1279-3:2018 - Glass in building - Insulating glass units - Part 3: Long term test method and requirements for gas leakage rate and for gas concentration tolerances

Relations

• Replaces: EN 1279-3:2002 - Glass in building - Insulating glass units - Part 3: Long term test method and requirements for gas leakage rate and for gas concentration tolerances
• Effective Date: 01-Aug-2018

Overview - EN 1279-3:2018 (CEN)

EN 1279-3:2018 is the CEN European standard that defines the long‑term test method and requirements for gas leakage rate and gas concentration tolerances in gas‑filled insulating glass units (IGUs). It specifies how to age specimens, measure gas loss, assess remaining gas concentration and set acceptance limits for factory production, component validation (edge seals, spacers) and product development.

Key topics and technical requirements

• Scope: Applies to IGUs made in accordance with EN 1279‑1:2018 and manufactured to EN 1279‑6:2018, or to tests demonstrating that components allow compliance with EN 1279‑1 Clause 6.
• Gas leakage rate (Li): Measured after defined climate exposure. Results are averaged over 2 to 4 specimens (manufacturer decides number). The standard sets an average limit and an absolute individual limit (see EN 1279‑3 for numeric thresholds and rounding rules).
• Gas concentration tolerances: Gas concentration after testing must not be more than 5 percentage points below the nominal concentration used to calculate declared U‑values.
• Durability and compatibility: Recommends inert gases (Ar, Kr, Xe). Use of other gases requires chemical compatibility testing with IGU components.
• Test procedure highlights: Climate exposure follows EN 1279‑2:2018 with modifications (e.g., cyclic exposure and an extended 58 °C step). Leakage measurement uses a hermetic container with temperature control; blank tests ensure container leakage ≤ 10% of specimen leak. Gas analysis equipment must detect low‑level constituents (see Annex A) and determine volume % up to 100% with ±3% (relative) accuracy. Annex A describes gas chromatography as the reference method.
• Specimen preparation: Typical specimens are two panes ≈4 mm thick with nominal dimensions (502 ±2 mm by 352 ±2 mm) representative of the system description.

Practical applications and who uses it

• IGU and window manufacturers - for product design, factory production control and to support declared U‑values.
• Component suppliers (edge seals, spacers) - to validate compatibility and sealing performance.
• Independent test laboratories and certification bodies - to perform standardized leakage and concentration testing.
• Architects, façade engineers and façade consultants - to interpret long‑term gas retention implications for thermal and acoustic performance.

Related standards

• EN 1279‑1:2018 - Generalities, system description, tolerances and visual quality
• EN 1279‑2:2018 - Moisture penetration long‑term test method
• EN 1279‑6:2018 - Factory production control and periodic tests
• EN 1279 series - broader guidance on IGU performance and testing

Keywords: EN 1279‑3:2018, insulating glass units, IGU, gas leakage rate, gas concentration tolerances, gas chromatography, climate exposure, edge seals, spacers, inert gases.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2018
1DGRPHãþD
SIST EN 1279-3:2004
6WHNORYJUDGEHQLãWYX,]RODFLMVNRVWHNORGHO'ROJRURþQDSUHVNXVQDPHWRGD
WHU]DKWHYH]DVWRSQMRXKDMDQMDSOLQDLQWROHUDQFHNRQFHQWUDFLMHSOLQD
Glass in building - Insulating glass units - Part 3: Long term test method and
requirements for gas leakage rate and for gas concentration tolerances
Glas im Bauwesen - Mehrscheiben-Isolierglas - Teil 3: Langzeitprüfverfahren und
Anforderungen bezüglich Gasverlustrate und Grenzabweichungen für die
Gaskonzentration
Verre dans la construction - Vitrage isolant préfabriqué scellé - Partie 3 : Méthode
d'essai à long terme pour le débit de fuite et prescriptions pour les tolérances de
concentration en gaz
Ta slovenski standard je istoveten z: EN 1279-3:2018
ICS:
81.040.20 Steklo v gradbeništvu Glass in building
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 1279-3
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2018
EUROPÄISCHE NORM
ICS 81.040.20 Supersedes EN 1279-3:2002
English Version
Glass in building - Insulating glass units - Part 3: Long term
test method and requirements for gas leakage rate and for
gas concentration tolerances
Verre dans la construction - Vitrage isolant - Partie 3 : Glas im Bauwesen - Mehrscheiben-Isolierglas - Teil 3:
Méthode d'essai à long terme pour le débit de fuite et Langzeitprüfverfahren und Anforderungen bezüglich
prescriptions pour les tolérances de concentration en Gasverlustrate und Grenzabweichungen für die
gaz Gaskonzentration
This European Standard was approved by CEN on 2 March 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1279-3:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 5
5 Requirements . 6
5.1 Gas leakage rate . 6
5.2 Tolerances on gas concentration. 7
5.3 Durability of the gas and interaction with IGU components . 7
6 Test method . 7
6.1 Principle of testing . 7
6.2 Apparatus . 7
6.2.1 Climate exposure equipment . 7
6.2.2 Container for gas leakage rate measurement . 7
6.2.3 Gas analysis equipment . 7
6.2.4 Gas sampling device . 8
6.2.5 Preparation of test specimens . 8
6.2.6 Number of test specimens . 8
6.3 Procedure. 8
6.3.1 Determination of internal volume V of a test specimen . 8
int
6.3.2 Climate exposure . 8
6.3.3 Measuring the gas leakage . 9
6.3.4 Analysis of gas . 9
6.4 Evaluation . 9
7 Test report . 10
Annex A (normative) Reference method for the determination of the gas leakage rate by gas
chromatography . 12
A.1 Principle of method . 12
A.2 Equipment . 12
A.3 Preparation of test specimens . 16
A.4 Procedure. 17
Annex B (informative) Relationship between artificial and natural ageing with regard to
thermal and sound insulation . 23

European foreword
This document (EN 1279-3:2018) has been prepared by Technical Committee CEN/TC 129 “Glass in
building”, the secretariat of which is held by NBN.
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 January 2019 and conflicting national standards shall
be withdrawn at the latest by January 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 1279-3:2002.
The main changes compared to the previous edition EN 1279-3:2002 are:
a) the standard has been fully technically and editorially revised;
b) the scope has been changed;
c) Terms and definitions and symbols have been split into two clauses;
d) requirement for gas leakage rate has been significantly changed;
e) the test method of this standard is also applicable to triple glazing units;
f) gas leakage rate can be determined after ageing a minimum two and a maximum four test
specimens. Durability of gas and interaction with IGU components has been added to requirements;
g) precision of the test method has been moved to A.4.8 and updated following a new inter-laboratory
test performed in 2009;
h) "Test report" has been revised adding a full description of the test specimen;
i) “Requirements for other gases” has been changed and moved to EN 1279-5:2018, Annex B: “Effect
of gas filling on U and Rw”.
j) “Gas leakage rate by gas chromatography” is now Annex A;
k) exchange criteria for gases are given in EN 1279-1:2018, Annex D.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
This document is part of the series EN 1279 “Glass in building - Insulating glass units” which consists of
the following parts:
— Part 1: Generalities, system description, rules for substitution, tolerances and visual quality;
— Part 2: Long term test method and requirements for moisture penetration;
— Part 3: Long term test method and requirements for gas leakage rate and for gas concentration
tolerances;
— Part 4: Methods of test for the physical attributes of edge seal components and inserts;
— Part 5: Product standard;
— Part 6: Factory production control and periodic tests.
These parts are inextricably bound up with each other.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
1 Scope
This European Standard describes the test method for the determination of gas leakage rate and
specifies the requirements for limit values for gas leakage rate and gas concentration for gas filled
insulating glass units made
a) in accordance with EN 1279-1:2018 and manufactured to EN 1279-6:2018, or
b) for the purpose to demonstrate that components (e.g. edge seals or spacers) will allow the
insulating glass unit to conform to the requirements given in EN 1279-1:2018, Clause 6.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 - Determination of thermal transmittance (U value) - Calculation method
EN 1279-1:2018, Glass in building - Insulating glass units - Part 1: Generalities, system description, rules
for substitution, tolerances and visual quality
EN 1279-2:2018, Glass in building - Insulating glass units - Part 2: Long term test method and
requirements for moisture penetration
EN 1279-6:2018, Glass in building - Insulating glass units - Part 6: Factory production control and
periodic tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1279-1:2018 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Symbols and abbreviations
Symbol Characteristic Unit
c concentration of gas i determined in accordance with 6.3.4 %
i
c nominal value for a system of insulating glass and gas i which is the basis %
i,o
for testing sound insulation and/or calculating or testing thermal
insulation to fix the respective R and U-value
w
m mass of gas that has leaked from a gas-filled unit in a given time µg/h
i
−1
L gas leakage rate %∙a
i
−1
L maximum gas leakage rate from all tested specimens %∙a
i,max
−1
L
average gas leakage rate for all tested specimens %∙a
i,av
P absolute atmospheric pressure at which the unit was sealed hPa
Symbol Characteristic Unit
P atmospheric pressure at which ρ was determined hPa
0 0
T temperature at which unit was sealed K
T temperature at which ρ was determined K
0 0
V internal volume of the test specimen according to 6.3.1 in mm
int
ρ density of gas i at temperature T and pressure P in µg/mm
0,i 0 0
5 Requirements
5.1 Gas leakage rate
The gas leakage rate Li for IGU containing gas(es) in concentrations higher than 15 % by volume per gas
are measured as described in Clause 6 and shall be determined on an average of at least two specimens
and maximum 4 specimens.
NOTE The number of specimens to be tested is decided by the manufacturer.
-1
L , ≤ 1,0 in % a
i av
-1
With an absolute limit of all individual L , ≤ 1,20 in % a
i max
Individual values shall be rounded to the second decimal place. Average value shall be rounded to one
decimal place.
EXAMPLE 1 Measurements of only two specimens:
a) 0,89 and 0,91 = > average 0,9, passed; no further measurement
b) 0,91 and 1,09 = > average 1,0, passed; no further measurement
c) 0,82 and 1,22 = > average 1,0, failed (1,22) ; no further measurement
d) 1,10 and 1,08 = > average 1,1 failed; further measurements optional: see option A or B
e) 0,98 and 1,15 = > average 1,1 failed; further measurements optional: see option A or B
Optional further measurements:
Option A:
— If with the 3rd specimen the mean value is ≤ 1,0:   passed
— If with the 3rd specimen the mean value stays > 1,0 but the value of the 3rd specimen is ≤ 1,20, test
the 4th specimen and if with the 4th specimen the mean value is ≤ 1,0:   passed.
— If the mean value of 4 specimens remain > 1,0:   failed
Option B:
Measure Li of further 2 specimens and if average value of the 4 tested specimens is less than 1,0 and no
individual value > 1,20:   passed
EXAMPLE 2 Measurements of 4 specimens
Measure directly 4 specimens and determine Li,av and Li,max and compare with requirements given.
For most insulating glass units, measured Li values are much higher than actual gas leakage values after
10 years of natural ageing. Therefore, the limiting value shall not be used for calculating the gas
concentration during the lifetime of the IGU. See also Annex B.
5.2 Tolerances on gas concentration
Gas concentration before and after the test procedure given in 6.3, shall not be lower than 5 % absolute
below the nominal value used to calculate the U-value declared by the IGU manufacturer.
5.3 Durability of the gas and interaction with IGU components
For the purposes of gas filling, only inert gases should be used like Ar, Kr, Xe. The use of any other gas
will require chemical compatibility tests to be carried out.
6 Test method
6.1 Principle of testing
The gas leakage rate at 20 °C is measured after subjecting the test specimens to a climate exposure as
specified in EN 1279-2:2018 with the following modifications:
— in step 1 the number of cycles is 28; and
— in step 2 the time at a constant temperature of 58 °C is 4 weeks.
For the measurement of the gas leakage rate, the specimen is placed in a gastight container and, after a
given time, the amount of gas which has leaked from the specimen is measured. After this
measurement, the gas concentration in the specimen is analysed and the gas leakage rate calculated.
6.2 Apparatus
6.2.1 Climate exposure equipment
Test apparatus for the climate exposure shall be as specified in EN 1279-2:2018.
6.2.2 Container for gas leakage rate measurement
A container with temperature control shall be used for measuring the gas leakage rate, which shall be
hermetically sealable, and capable of receiving the specimen. Under the test conditions as little stress as
possible shall be induced and the residual volume in the container shall be as small as possible. The
sealed edges of the test specimens shall be exposed to the circulating purging gas (see Annex A).
The quantity of ambient air penetrating into the container from outside, or the quantity of each
constituent leaking from the container, shall be measured in a blank test using a solid glass body of
approximately the same dimensions as the test specimens.
The container shall be deemed to have an adequate degree of tightness if the measured quantity of gas
during the blank measurement does not exceed 10 % of the mass of gas leaking from the test specimen.
The container shall have fittings for introducing specific gases and for taking gas samples.
6.2.3 Gas analysis equipment
Gas analysis equipment shall be used which is capable of:
— analysis of the gaseous constituents essential to the insulation function of the glass unit, for
−6
concentrations of 50 · 10 ;
— determination of percentages by volume of gas of up to 100 % within ± 3 % (relative).
These tasks need not be performed using the same equipment.
6.2.4 Gas sampling device
A device shall be used for taking gas samples from the tested IGU specimens, ensuring that the result is
not distorted by ingress of air, segregation phenomena, or similar. The gas samples shall be
representative for the whole gas volume.
6.2.5 Preparation of test specimens
The test specimens shall be representative of the system description (see EN 1279-1:2018, Annex A)
and shall consist of two panes of 4 mm glass in accordance with EN 1279-1:2018, 5.2. If 4 mm glass is
not available, the thickness as near as possible to 4 mm shall be used. The length shall be (502 ± 2) mm
and the width (352 ± 2) mm. The cavity width shall be nominal 12 mm, or if not manufactured, a cavity
width as near as possible to 12 mm.
Specimens of triple glazed units may also be tested. Length, width and cavity width should fulfil the
above mentioned descriptions. The gas loss rates of the individual cavities may be different. Therefore,
only an average value can be given. There is no specific requirement on individual cavities.
The panes of the test specimen shall be flat when the unit is sealed. During sealing, the ambient
temperature, T is measured in °C and recorded in K, and the absolute pressure, P in hPa, shall be
measured and recorded. The test specimens shall be manufactured in such a way that the gas
concentration shall not be lower than 5 % absolute of the declared value ci,o, for each gas when gas
mixtures are used.
6.2.6 Number of test specimens
At least six test specimens shall be prepared of which at least two shall be tested as described in 6.3.3
after climate exposure.
6.3 Procedure
6.3.1 Determination of internal volume V of a test specimen
int
Measure the clear distance between opposite spacers, d1 and d2, to the nearest 1 mm, e.g. by means of a
gauge graduated in millimetres. Determine the clear distance between the inner pane surfaces, d3, by
measuring the distance between the inner pane surfaces at mid-length on the four edges of the test
specimen, to the nearest 0,1 mm, and calculate the mean. The internal volume, V in mm , is obtained
int
in accordance with Formula (1):
Vd = 1 ⋅⋅d2 d3 (1)
int
6.3.2 Climate exposure
The climate exposure as specified in 6.1 sha
...