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
UK Net Zero Carbon Buildings Standard V1 published
Free-to-access technical standard to enable robust proof of a decarbonising built environment.
Prostate Cancer Awareness Month
Why talking about prostate cancer matters in construction.
The Architectural Technology podcast: Where it's AT
Catch up for free, subscribe and share with your network.
The Association of Consultant Architects recap
A reintroduction and recap of ACA President; Patrick Inglis' Autumn update.
The Home Energy Model and its wrappers
From SAP to HEM, EPC for MEES and FHS assessment wrappers.
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.
Planning reform: draft NPPF and industry responses.
Last chance to comment on proposed changes to the NPPF.
A Regency palace of colour and sensation. Book review.
Delayed, derailed and devalued
How the UK’s planning crisis is undermining British manufacturing.
How much does it cost to build a house?
A brief run down of key considerations from a London based practice.
The need for a National construction careers campaign
Highlighted by CIOB to cut unemployment, reduce skills gap and deliver on housing and infrastructure ambitions.
AI-Driven automation; reducing time, enhancing compliance
Sustainability; not just compliance but rethinking design, material selection, and the supply chains to support them.
Climate Resilience and Adaptation In the Built Environment
New CIOB Technical Information Sheet by Colin Booth, Professor of Smart and Sustainable Infrastructure.
Turning Enquiries into Profitable Construction Projects
Founder of Develop Coaching and author of Building Your Future; Greg Wilkes shares his insights.
IHBC Signpost: Poetry from concrete
Scotland’s fascinating historic concrete and brutalist architecture with the Engine Shed.





















