ISO 10291-1994 PDF

Full title and description

ISO 10291:1994 — Glass in building — Determination of steady‑state U values (thermal transmittance) of multiple glazing — Guarded hot plate method. This International Standard specifies a laboratory measuring method (guarded hot plate) for determining the steady‑state thermal transmittance (U‑value) of multiple glazing units with flat, parallel panes, including cast and figured rolled glass, under controlled boundary conditions.

Abstract

Specifies the guarded hot plate measurement procedure used to determine the coefficient of thermal transmittance (U‑value) of multiple glazing. The method applies to glazing whose outer panes are not transparent to far‑infrared radiation (as is normal for window glass); internal elements may be far‑infrared transparent. The standard defines measurement conditions, specimen handling and reporting necessary to obtain steady‑state U‑values for the central area of test specimens.

General information

• Status: Published (International Standard; action confirmed through periodic review).
• Publication date: September 1994 (first published 1994‑09; distribution records commonly show 15 September 1994).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 81.040.20 — Glass in building.
• Edition / version: Edition 1 (1994).
• Number of pages: 5.

Key bibliographic and lifecycle details above are taken from the ISO bibliographic record and distribution catalogues.

Scope

ISO 10291:1994 applies to laboratory determination of steady‑state U‑values for multiple (insulating) glazing with flat, parallel panes using a guarded hot plate apparatus. It covers specimen preparation, measurement conditions and calculation/reporting of the U‑value for the central area of specimen assemblies; the method assumes outer panes that are opaque in the far‑IR and does not treat edge‑effects or in‑service whole‑frame measurements. The standard is intended to produce reproducible laboratory U‑values for product assessment and research.

Key topics and requirements

• Guarded hot plate apparatus — apparatus arrangement and guarded‑metered section concept for steady‑state heat flux measurement.
• Specimen description — multiple glazing assemblies with flat, parallel panes (including cast and figured rolled glass).
• Boundary and test conditions — stabilized steady‑state temperatures, defined heat flow and reporting conventions.
• Calculation and reporting of U‑value for the central (non‑edge) area of the glazing specimen.
• Limitations — outer panes must be non‑transparent to far‑infrared; edge effects and frames are excluded from the central‑area measurement.

Concepts and method context follow the ISO method description and conventional guarded hot plate practice.

Typical use and users

Primary users are accredited test laboratories, glazing and insulating glass manufacturers, research institutions studying thermal performance of glazing systems, product certification bodies and standards bodies developing or harmonizing thermal performance assessment procedures. The standard is used where precise laboratory U‑values for the central area of insulating glazing are required (product development, validation, and research).

Related standards

Directly related documents include ISO 10292:1994 (calculation procedures for steady‑state U values of multiple glazing) and various regional/sector standards that define calculation and declaration methods for glazing U‑values (examples include European EN/EN‑series methods for U‑value calculation such as EN 673 and national/adopted variants). The guarded hot plate technique itself is aligned with general guarded‑hot‑plate test practices (for example ASTM C177) used for steady‑state heat flux measurements. These related standards provide complementary calculation procedures, declaration rules and broader test context.

Keywords

glass in building; insulating glazing; U‑value; thermal transmittance; guarded hot plate; steady‑state measurement; glazing testing; thermal performance; ISO 10291.

FAQ

Q: What is this standard?

A: ISO 10291:1994 is an International Standard that specifies a laboratory (guarded hot plate) method for determining the steady‑state U‑value (thermal transmittance) of multiple glazing assemblies.

Q: What does it cover?

A: It covers specimen description, guarded hot plate measurement procedure, test conditions and reporting for central‑area U‑value determination of multiple glazing with flat, parallel panes; edge effects and frames are excluded.

Q: Who typically uses it?

A: Accredited test laboratories, glazing manufacturers, product developers, certification bodies and researchers who need laboratory‑measured U‑values for insulating glazing units.

Q: Is it current or superseded?

A: ISO 10291:1994 is the 1994 edition; ISO’s record shows the published standard and indicates periodic review/confirmation action. As of the latest ISO bibliographic lifecycle entries the standard remained published and has been subject to systematic reviews/confirmations. Users should check national/regional catalogues for any more recent replacements or newer editions before relying on it for regulatory compliance.

Q: Is it part of a series?

A: Yes — it sits with other ISO documents on glazing thermal performance (for example ISO 10292 provides calculation methods for U‑values). Regional standards (EN series) and ASTM test methods cover complementary calculation or guarded‑hot‑plate practices. These related documents are commonly referenced together when assessing glazing thermal performance.

Q: What are the key keywords?

A: U‑value, thermal transmittance, insulating glazing, guarded hot plate, steady‑state measurement, glass in building, ISO 10291.