Key findings

• In general it was found that the more sophisticated the optical heat multi-sensors were, the less prone they were to common causes of false alarms.

• The ability of these heat multi-sensors to detect real fires was not compromised.

• This research will support the development of product standards and codes of practice for smoke and multi-sensor detectors.

Report summary

Since 2013 BRE has been involved in two studies investigating how false alarms from fire detection systems can be reduced. They showed that the greater use of multi-sensor detectors could help to reduce false alarms from common causes such as cooking, steam, dust and aerosol sprays.

Multi-sensor detectors use a combination of more than one type of sensor – smoke, heat or carbon monoxide – to detect the presence of a fire. A research group comprising the Fire Industry Association, BRE and fire detector manufacturers, has now investigated the immunity of multi-sensor detectors containing smoke and heat sensors to common causes of false alarms, as well as to real fires.

Targeting the more common causes of false alarms five tests were developed and used during this research. These were water mist, dust and aerosol tests performed at the University of Duisburg-Essen, together with toast and cooking tests conducted in the BRE Fire Test room. For all false alarm tests the multi-sensors operated, on average, after the smoke detectors.