false alarm reduction Raman Chagger Principal Consultant, Fire - - PowerPoint PPT Presentation

Part of the BRE Trust

Research into multi-sensor detector capabilities and false alarm reduction

Raman Chagger Principal Consultant, Fire Safety Group, BRE FIREX, 20th June 2018

Introduction

– Losses from false fire alarms ~£1 billion/year in the UK – False alarms have consequences:

• FRS – drain on/diverted resources
• Businesses – disruptions/loss of productivity
• Public - reduced confidence/frustration
• Road traffic accidents

False alarm studies

Study 1: The causes of false fire alarms in buildings Study 2: Live investigations of false fire alarms

False alarm studies

Study 1: KCL 6 recommendations Potentially 49.5% reduction through the greater use of multi-sensors. Study 1: BMKFA Potentially 27.0% reduction through the greater use of multi-sensors. Study 2: SFRS 35 recommendations Potentially 35.1% reduction through the greater use of multi-sensors.

– Multi-sensors utilise a number of sensors to provide more reliable detection – Research with SFRS identified that no false alarms were caused from multi-sensor detectors – One of the recommendations “Further research is required to identify multi- sensors performance variabilities and capabilities”. – As well as greater reliability fire sensitivity levels can be increased reducing detection times.

Multi-sensor detectors Heat Optical smoke Carbon Monoxide

Photo courtesy of Tyco Fire Protection Products

– The BRE Trust, 12 manufacturers and the Fire Industry Association started a 3 phase research project – Phase 1: Review of multi-sensor capabilities and variabilities. Identify tests – Phase 2: Performing a broad range

• f test fires (compare with optical)

– Phase 3: Performing a broad range

• f common false alarm tests to

identify multi-sensor immunity. – Aim of identifying relative benefits of multi-sensors over optical detectors

Optical/heat multi-sensor detector research

Video

Phase 1: Identification of false alarm tests

Dust (long term) Dust (short term) Smoke from cooking Steam Condensation Aerosols (hairspray/deodorant) Smoke from toaster Cigarette smoke Synthetic (smoke machines) Insects Thermal shock

Apparatus for the Test of Fire Detectors in Dusty Environments (AUBE14_S09P02)

Phase 1: Identification of false alarm tests

Dust (long term) Dust (short term) Smoke from cooking Steam Condensation Aerosols (hairspray/deodorant) Smoke from toaster Cigarette smoke Synthetic (smoke machines) Insects Thermal shock

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 600 800 1000 1200

m (dB/m) Time (sec)

Smoke from cooking

Test 1 Test 2 Test 3 Test 4 Test 5

Phase 1: Identification of false alarm tests

Dust (long term) Dust (short term) Smoke from cooking Steam Condensation Aerosols (hairspray/deodorant) Smoke from toaster Cigarette smoke Synthetic (smoke machines) Insects Thermal shock

Apparatus for the Test of Fire Detectors in High Foggy Environments (AUBE14_S09P02)

Phase 1: Identification of false alarm tests

Dust (long term) Dust (short term) Smoke from cooking Steam Condensation Aerosols (hairspray/deodorant) Smoke from toaster Cigarette smoke Synthetic (smoke machines) Insects Thermal shock

• Aerospace standard AS8036

(2013-12)

• Cargo Compartment Fire

Detection Instruments

Phase 1: Identification of false alarm tests

Dust (long term) Dust (short term) Smoke from cooking Steam Condensation Aerosols (hairspray/deodorant) Smoke from toaster Cigarette smoke Synthetic (smoke machines) Insects Thermal shock

0.0 0.5 1.0 1.5 2.0 2.5 3.0 300 350 400 450 500 550 600

m (dB/m) Time (sec)

Smoke from toast

Test 1 Test 2 Test 3 Test 4 Test 5

Phase 1: Identification of fire tests

Test fire m:y (dB/m) Δ t (°C) ABS (S) 3.04 2.9 Flame retardant PU foam (S) 1.88 2.5 TF2 Wood (S) 1.08 1.8 TF3 Cotton (S) 0.528 2.0 TF4 PU foam (F) 0.235 21 TF5 N-heptane (F) 0.168 35 TF8 Decalin (F) 0.25 6 Nylon (F) 0.168 5 Flame retardant PU foam (F) 0.094 5 TF1 wooden crib (F) 0.079 24 (F) = Flaming; (S) = Smouldering

Utilised the methodology from previous work into test fires

Phase 2: Fire tests

– 36 types of different optical heat multi-sensor detectors tested alongside 2 reference optical smoke detectors – Multi-sensors categorised in terms of their false alarm immunity

Phase 2: Fire tests (PU Foam example)

Phase 2: False alarm tests (Toast example)

Phase 2: False alarm tests (overview)

216% 182% 191% 248% 207%

0% 50% 100% 150% 200% 250% Toast (dB/m) Cooking (dB/m) Water mist (dB/m) Dust (dB/m) Aerosol (sec. dB/m)

Multi-sensor response normalised to optical (%) False alarm test Multi-sensor detector average Optical smoke devices average

Phase 2: False alarm tests (overview)

Conclusion

• Research has demonstrated that multi-

sensor detectors can have the same response to fire but delayed response to false alarms

• The performance is dependent on the

sensitivity levels

• FIA and BRE are working to intending

to develop a Loss Prevention Standard for False Alarm Resistance

• FIA guidance on false alarm reduction

available from: http://www.fia.uk.com/cut-

false-alarm-costs.html

• BRE briefing papers (+ videos) are

available free of charge from:

http://www.bre.co.uk/firedetectionresearch

Thanks

• S. Brown

Consulting Services Ltd

Thanks to UBM for use of images in this presentation