ISO 5925:2025

Overview

ISO 5925:2025 specifies a standardized test method for measuring smoke leakage through smoke-control door and shutter assemblies and self-closing operable glazed elements. The standard covers both ambient-temperature (cold) and medium-temperature (warm) leakage tests, defining test apparatus, instrumentation, specimen preparation, procedures, observations and reporting. ISO 5925:2025 provides repeatable, laboratory-based methods to determine the leakage rate (m3/h) of smoke under defined differential pressure and temperature conditions. The standard does not set acceptable leakage limits; those are determined by regulators or project specifications.

Key topics and technical requirements

• Scope: Applies to door/shutter assemblies and self-closing glazed elements intended for smoke control. Fire resistance for glazed elements is addressed in ISO 3009.
• Test conditions:
  • Ambient temperature: 20 ± 10 °C.
  • Medium temperature: 200 ± 10 °C.
• Test chamber and apparatus: Typical opening around 3 m × 3 m (smaller for single-leaf doors). Apparatus leakage q_a shall not exceed 7 m3/h. Air supply/heating must replace leakage up to 55 m3/h and create a differential pressure of at least 55 Pa across the specimen.
• Instrumentation: Differential pressure measured to ±5 Pa or 10% of value; medium-temperature tests use 12 thermocouples arranged in four rows of three for temperature control and monitoring.
• Specimen and procedure: Includes requirements for number, size, construction, conditioning, pre-test analysis, set-up, air leakage measurement, observations and expression of results. Annexes provide test principle, apparatus guidance and commentary on applicability.
• Recent updates (3rd edition): added self-closing glazed elements, medium-temperature tolerance, option to run both medium-temperature tests on same specimen, moisture/evaporation controls, and procedural refinements (outlet valve, post-test operability checks).

Applications and users

ISO 5925 is used to:

• Verify smoke leakage performance of smoke-control doors, shutters and glazed elements.
• Support product development, third‑party certification and type testing in fire safety engineering.
• Provide laboratory data for smoke containment strategies used by architects, fire engineers and building authorities.

Typical users:

• Test laboratories and certification bodies
• Manufacturers of fire and smoke-control doors and glazed assemblies
• Fire safety engineers, consultants and code authorities
• Specifiers and facility managers responsible for passive fire protection

Related standards

• ISO 3009 - fire resistance tests for glazed elements (referenced for fire resistance)
• ISO 834-1 - standardized fire curves and general fire-resistance test requirements
• ISO 3008 series - related fire door standards and guidance

Keywords: ISO 5925, smoke-control door, leakage tests, ambient-temperature, medium-temperature, smoke leakage rate, fire safety, self-closing glazed elements.