Overview
ISO 12567-1:2010 - "Thermal performance of windows and doors - Determination of thermal transmittance by the hot‑box method - Part 1: Complete windows and doors" specifies a standardized laboratory method to measure the thermal transmittance (U‑value) of complete window and door systems using a calibrated or guarded hot‑box. The procedure accounts for frames, sashes, shutters, blinds, screens, panels, door leaves and fittings, and provides corrections for edge/boundary effects to produce reproducible U‑value results for product comparison and performance evaluation.
Key topics and technical requirements
- Measurement principle: Two‑stage hot‑box method based on ISO 8990 - calibration with known panels, then measurement of the specimen using the same fan and boundary conditions.
- Scope and exclusions: Applicable to complete windows and doors; not applicable to edge effects outside the specimen perimeter, solar radiation on the specimen, air leakage through the specimen, or projecting/roof windows (see ISO 12567‑2 for projecting products).
- Surround and calibration panels: Use of a surround panel to position specimens and calibration panels with known thermal properties to determine surface heat transfer coefficients (radiative and convective).
- Edge correction: Linear thermal transmittance (Ψ) correction for boundary/edge heat flow as given in Annex B or calculated per ISO 10211.
- Test specimen preparation: Specimen mounting, sealing (gaps ≤ 5 mm guidance) and measures to prevent air permeability affecting results (pressure equalization or internal sealing).
- Data and reporting: Instructions for test procedure, expression of standardized results, and required test report content.
- Uncertainty and calibration: Annexes include environmental temperature calculations (A), calibration examples (D), analytical calibration (E), and uncertainty analysis for hot boxes (F).
- Normative references: ISO 8990, ISO 7345, ISO 8301, ISO 8302, ISO 9288, ISO 10211, EN 12898, IEC 60584‑1.
Applications and who uses it
ISO 12567‑1 is used by:
- Test laboratories performing U‑value measurements on windows and doors.
- Manufacturers validating product thermal performance for datasheets and quality control.
- Product certifiers and compliance bodies assessing conformity with building regulations and energy labeling.
- Architects, façade engineers and energy assessors requiring reliable laboratory U‑values for building energy models.
- Research institutions investigating thermal bridge effects, glazing systems and façade performance.
Practical uses include product comparison, compliance documentation, input for building energy simulation, and R&D of low‑U glazing and frame systems.
Related standards
Keywords: ISO 12567‑1, thermal transmittance, U‑value, hot‑box method, windows and doors, thermal performance, calibration, surround panel, linear thermal transmittance, measurement uncertainty.