Visual alarm devices - their effectiveness in warning of fire
Research by BRE looked at the effectiveness of visual alarm devices in warning building occupants of fire.
The research compared the responses of a group of participants to flashing Xenon and LED devices of varying pulse durations. One Xenon device, three cool white LED devices (of 40, 20 and 10 millisecond (ms) pulse durations) and two warm white LED devices (of 40 and 20ms pulse durations) were used.
The flashing signals were presented individually to 96 participants who were seated in front of a screen and occupied with a written task. The tests were performed in high and low ambient light level conditions. The devices were flashed one at a time, and from a distance of 19m were gradually brought closer to the screen until the subjects responded. The response data was processed to identify the effective illumination levels required to alert people to the flashing signals from the six devices.
Analysis of this data revealed that as the pulse durations of LED devices shorten, the attention drawing effectiveness increases. It also demonstrated no significant difference in responses between warm white LED devices and cool white LED devices. The Xenon and 10ms cool white LED device had similar responses; however, a cool white LED device with a pulse duration of 5ms may out-perform a Xenon device.
Find out more and see the full project report on the BRE Group website.
[edit] Related articles on Designing Buildings Wiki
- Automatic fire detection and alarm systems, an introductory guide to components and systems BR 510.
- Carbon monoxide detector.
- Combustion appliance.
- Evacuating vulnerable and dependent people from buildings in an emergency FB 52.
- Fire and rescue service.
- Fire dampers.
- Fire detection and alarm system.
- Fire detector.
- Fire performance of external thermal insulation for walls of multistorey buildings, third edition (BR 135).
- Fire protection engineering.
- Fire safety design.
- Fire.
- Heat alarm.
- Intelligent building management systems IBMS.
- Ionisation smoke alarms.
- Optical smoke alarm.
- Personal protection watermist systems in the homes of vulnerable people.
- Smoke detector.
- The causes of false fire alarms in buildings.
- Understanding the factors affecting flashover of a fire in modern buildings.
- Visual alarm devices for fire: An introduction and guide to BS EN 54-23.
Featured articles and news
Level 6 Design, Construction and Management BSc
CIOB launches first-ever degree programme to develop the next generation of construction leaders.
Open for business as of April, with its 2026 prospectus and new pipeline of housing schemes.
The operational value of workforce health
Keeping projects moving. Incorporating unplanned absence and the importance of health, in operations.
A carbon case for indigenous slate
UK slate can offer clear embodied carbon advantages.
Costs and insolvencies mount for SMEs, despite growth
Construction sector under insolvency and wage bill pressure in part linked to National Insurance, says report.
The place for vitrified clay pipes in modern infrastructure
Why vitrified clay pipes are reclaiming their role in built projects.
Research by construction PR consultancy LMC published.
Roles and responsibilities of domestic clients
ACA Safety in Construction guide for domestic clients.
Fire door compliance in UK commercial buildings
Architect and manufacturer gives their low down.
Plumbing and heating for sustainability in new properties
Technical Engineer runs through changes in regulations, innovations in materials, and product systems.
Awareness of the Carbon Border Adjustment Mechanism
What CBAM is and what to do about it.
The new towns and strategic environmental assessments
12 locations of the New Towns Taskforce reduced to 7 within the new towns draft programme and open consultation.
Buildings that changed the future of architecture. Book review.
The Sustainability Pathfinder© Handbook
Built environment agency launches free Pathfinder© tool to help businesses progress sustainability strategies.
Government outcome to the late payment consultation, ECA reacts.
IHBC 2025 Gus Astley Student Award winners
Work on the role of hewing in UK historic conservation a win for Jack Parker of Oxford Brookes University.





















