ISO 10292-1994 PDF

Full title and description

ISO 10292:1994 — Glass in building — Calculation of steady-state U values (thermal transmittance) of multiple glazing. This International Standard provides the calculation method for determining the steady-state thermal transmittance (U value) of multiple glazed units and related glass assemblies for use in building heat-loss/gain assessments and energy calculations.

Abstract

Specifies fundamental rules for calculating steady-state U values of multiple glazing (central area only; edge effects excluded). Applies to uncoated and coated glass and materials that are opaque in the far-infrared. The procedures are intended to enable estimation of heat loss through glazing for building heating/cooling loads and other purposes (e.g., condensation risk, seasonal heat-loss calculations).

General information

• Status: Published (International Standard; last reviewed and confirmed 2023; under review for revision).
• Publication date: July 1994.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 81.040.20 (Glass in building).
• Edition / version: Edition 1 (1994).
• Number of pages: 8 pages.

Key bibliographic and lifecycle information as recorded by ISO.

Scope

Covers calculation of steady-state thermal transmittance (U value) for flat, parallel multiple-glazing units and similar glazing assemblies in their central area. The standard excludes edge effects from spacers and thermal bridges and does not consider solar radiation effects; it applies to glass, coated glass and other materials opaque in the far infrared and is intended for use in building energy calculations and related assessments.

Key topics and requirements

• Definition and physical assumptions for steady-state heat transfer through multiple glazing (central area calculations).
• Input properties required: layer thermal resistances, emissivities, gas fill properties, spacing and glazing configuration.
• Calculation procedure for U value of multiple glazing (radiative, convective and conductive components in the central pane area).
• Exclusions and limitations: edge spacer effects, frame thermal bridges and solar radiation are outside the scope.
• Intended outputs: U values suitable for building heat-loss calculations, condensation assessment and seasonal energy estimates.

Typical use and users

Used by façade and glazing engineers, window and glazing manufacturers, building energy consultants, architects, HVAC designers, and researchers needing standardized methods to calculate glazing U values for energy performance assessments, product comparison, and building services sizing.

Related standards

Closely related documents include standards for whole-window U-value calculation and frame numerical methods (for example ISO 10077 series) and regional/European calculation methods for glazing (EN 673). ISO has indicated development of a successor draft ISO/DIS 10292 to update and replace ISO 10292:1994.

Keywords

glass in building; glazing; U value; thermal transmittance; multiple glazing; steady-state calculation; emissivity; gas fill; heat loss; condensation; ISO 10292.

FAQ

Q: What is this standard?

A: ISO 10292:1994 is an International Standard that specifies a calculation method for the steady-state thermal transmittance (U value) of multiple glazing (central area calculations).

Q: What does it cover?

A: It covers the assumptions, input data and calculation procedure needed to determine U values for flat, parallel multiple-glazing units (applies to uncoated and coated glass and materials opaque in the far infrared); edge effects, frames and solar effects are excluded.

Q: Who typically uses it?

A: Architects, glazing and façade engineers, window manufacturers, building energy assessors, HVAC designers and researchers who need standardized glazing U-value calculations for design, compliance and performance evaluation.

Q: Is it current or superseded?

A: The 1994 edition is published and—according to ISO—was last reviewed and confirmed in 2023; ISO has indicated the standard is to be revised and a draft (ISO/DIS 10292) is under development as the successor. Users should check for the latest status or an updated edition before relying on it for new compliance work.

Q: Is it part of a series?

A: It is a stand‑alone ISO standard focused on glazing U-value calculation but is commonly used alongside related standards for whole-window and frame calculations (for example the ISO 10077 series) and regional standards such as EN 673.

Q: What are the key keywords?

A: U value, thermal transmittance, glazing, multiple glazing, emissivity, gas fill, steady-state calculation, glass in building, condensation.