Overview
ISO 20492-3:2010 - Glass in buildings - Insulating glass - Part 3: Gas concentration and gas leakage specifies laboratory test methods for measuring the gas concentration and gas leakage behaviour of sealed, gas-filled insulating glass units (IGUs). The standard defines two approaches: Approach 1 (intended for markets such as North America) and Approach 2 (intended for markets such as Europe). It supports evaluation of energy and acoustic performance retention, and the durability of edge seals under climate exposure.
Key topics and technical requirements
- Scope: Two test methods to determine gas leakage rate and gas concentration tolerances for sealed IGUs. Applies to IGUs used in buildings (windows, doors, curtain walling, skylights, roofs and partitions) where edges are protected from direct UV.
- Two approaches:
- Approach 1: Gas chromatographic separation of argon, oxygen and nitrogen comparing sample peaks to reference standard mixtures. Requires a gas sampling valve (100–250 µL), an adsorption column to separate argon, and reproducible chromatograms (component peak areas within ±0.1 %). Minimum average fill for eight argon-filled specimens is 90 %.
- Approach 2: Measures gas leakage rate after defined climate exposure (modified ISO 20492‑1: 28 cycles; 4 weeks at 58 °C at constant temperature). The gas leakage rate Li at 20 °C shall satisfy Li < 1.00 % per year for gases with concentrations >15 % and for air. Units are measured inside a hermetic, temperature-controlled container.
- Definitions and conditions: Standard laboratory conditions (23 ± 2 °C, RH 50 ± 5 %) and controlled limit environment (10 °C, dew point −5 °C) are specified.
- Ancillary tests: Tolerances on gas concentration follow EN 1279-6:2002 Annex A.3. Dew-point, moisture penetration and edge-seal strength referenced to ISO 20492‑1 and ISO 20492‑4.
- Annexes: Calibration/standardization of chromatograph (A), requirements for other gases (B), relation of artificial vs natural ageing (C), gas chromatographic method for leakage determination (D).
Practical applications and users
ISO 20492-3:2010 is used by:
- Insulating glass manufacturers for quality control and production testing of gas-filled IGUs (argon, SF6, other gases)
- Independent testing laboratories performing gas concentration and leakage measurements
- Specifiers, façade engineers, architects and façade manufacturers who require validated performance data (U value, sound insulation) over time
- Certification bodies and regulatory authorities enforcing product standards and factory production control
Related standards
- ISO 20492-1 (Durability of edge seals by climate tests)
- ISO 20492-4 (Methods of test for physical attributes of edge seals)
- EN 1279-6:2002 (Factory production control and periodic tests)
- ISO 16293-1, ASTM C1036
Keywords: ISO 20492-3:2010, insulating glass, gas leakage, gas concentration, argon fill, gas chromatograph, gas leakage rate, edge seals, insulating glass units (IGUs).
