7.1 Smoke Detector Performance

Transcription

1 7.1 Smoke Detector Performance Paul E. Patty, P.E. Senior Research Engineer Northbrook X paul.e.patty@us.ul.com

2 Smoke Detector Performance Smoke Characterization Project Quality of smoke Material characteristics Smoke movement Photo/Ion response STP Activities Improving response Nuisance issues NFPA 72 Chapter 11 Task Group Activities Tenability issues Media Coverage Photoelectric/Ionization Alarms Is there a hazard? Recommendations p/2

3 Smoke Detector Performance Smoke Characterization Project Quality of smoke Color black, grey, yellow, white Particle size microns Velocity > 32ft/min. Temperature <150 degrees F Build-up rate obscuration %/ft/min. Gases of combustion p/3

4 Smoke Characterization Project Material characteristics Develop smoke characterization analytical test protocol using flaming and non-flaming modes of combustion. Develop smoke particle size distribution data and smoke profiles in the UL smoke detector room for materials found in residential settings for both flaming and non-flaming modes of combustion. Survey Materials Survey materials and products in contemporary residential settings Selection of materials for the research investigation based on: Presence in residential settings Chemistry UL 217 specifications p/4

5 Smoke Characterization Project Sampling Method Calorimeter N 2 dilution FTIR Every 15 s Smoke Particle Every 67 s p/5

6 Smoke Characterization Project Smoke Particle Analyzer Data PET Carpet 1.3E+06 p/6 Particle density (1/cc) 1.0E E E E E Time (s) Particle Size (nm)

7 Smoke Characterization Project Key Findings - Gas Analysis Smoke Gas Effluent Composition - Gas effluent analysis showed the dominant gas components were water vapor, carbon dioxide and carbon monoxide. Water CO 2 CO SO 2 NO 2 Methane Ammonia Phenol SiF 4 Formaldehyde HCN Propane HCl HF Ethylene Acrylonitrile Styrene p/7

8 Smoke Characterization Project Key Findings - Influence of Material Chemistry Flaming Mode UL 217 materials Peak HRR (kw/m² ) Cooking oil Heptane Heptane/ Toluene mix Douglas fir Newspaper Pond. pine HDPE Bread Mattress composite Mattress PU foam Cotton batting Polyester pillow stuffing Cotton/Polyester blend fabric Rayon fabric Nylon carpet PET carpet Polyisocyanurate foam PVC wire 0 p/8

9 Smoke Characterization Project Key Findings - Mode of Combustion Flaming Non-Flaming 0.20 UL 217 materials p/9 Mean Particle Diameter (micron) Cooking oil Bread Newspaper Douglas fir Ponderosa pine Cotton batting Cotton/Polyester blend (fabric) Rayon (fabric) HDPE Nylon carpet Polyester carpet Polyester filling PU foam Polyisocyanuarate foam PVC

10 Smoke Characterization Project Key Findings - Mode of Combustion Flaming Non-Flaming UL 217 materials Specific Extinction Area (m²/g) Cooking oil Bread Newspaper Douglas fir Ponderosa pine Cotton batting Cotton/Polyester blend (fabric) Rayon (fabric) HDPE Nylon carpet Polyester carpet Polyester filling PU foam Polyisocyanuarate foam PVC p/10

11 Smoke Characterization Project Key Findings Particle size Flaming Tests Mean Diameter at: 0.5 %/ft 10 %/ft Douglas fir Newspaper Heptane/Toluene Coffee maker PU foam 0.08 NA PU foam in Cotton/Poly 0.09 NA Nylon carpet 0.10 NA p/11

12 Smoke Detector Performance Smoke movement Smoke Stratification - Non-flaming fires result in changes in the smoke build up over time, such that stratification of smoke below the ceiling occurs. This time-dependent phenomenon results in less obscuration at the ceiling than below the ceiling. This caused both detection technologies to drift out of alarm. p/12

13 Smoke movement Before Before Key Findings - Fire Test Room After p/13

14 Smoke movement 12 4 in below ceiling 24 in. below ceiling in. below ceiling 60 in below ceiling 8 OBS (%/ft) 6 4 PU foam in Poly Time (sec) p/14

15 Smoke movement in below ceiling 24 in. below ceiling 36 in. below ceiling 60 in. below ceiling 8 OBS (%/ft) 6 4 PU foam in Cotton Time (sec) p/15

16 Smoke Detector Performance (Photo/Ion Response Fire Test Room MIC 1) Non-Flaming Tests Bread Bread Bread MIC Signal Change (pa) Nylon Carpet Polyisocyanurate Foa m Polystyrene Ponderosa Pine Ponderosa Pine Ponderosa Pine Ponderosa Pine Ponderosa Pine PU Foam PU Foam PU Foam PU + cotton PU + cotton PU + poly PU + Poly 0 0.0E E E E E E+06 Σ(n i d i ) p/16

17 Photo/Ion Response Fire Test Room MIC Flaming Tests 80 MIC Signal Change (pa) Coffee Maker Coffee Maker Nylon carpet Nylon carpet Nylon carpet PU Foam PU Foam + cotton/poly PU Foam + cotton/poly PU Foam + cotton/poly PU Foam + cotton/poly 0 0.0E E E E E E+06 Σ(n i d i ) p/17

18 Photo/Ion Response Fire Test Room Analog Ion 1 70 Bread 60 Bread Bread Nylon Carpet Analog Ion Signal Change Isocyanuarate Foam Polystyrene Ponderosa Pine Ponderosa Pine Ponderosa Pine Ponderosa Pine PU Foam PU Foam PU Foam PU Foam 10 PU Foam + cotton Non-Flaming Tests PU Foam + poly PU Foam + poly 0 0.0E E E E E E+06 Σ(n i d i ) p/18

19 Photo/Ion Response Fire Test Room Analog Ion 2 Analog Ion Signal Change 70 Coffee Maker Coffee Maker Douglas Fir 60 Douglas Fir Douglas Fir 50 Heptane/Toluene Heptane/Toluene Heptane/Toluene 40 Heptane/Toluene Newspaper Newspaper 30 Newspaper Nylon Carpet Nylon Carpet 20 Nylon Carpet PU Foam 10 PU Foam + cotton/poly Flaming Tests PU Foam + cotton/poly PU Foam + cotton/poly 0 PU Foam + cotton/poly 0.0E E E E E+05 Σ(n i d i ) p/19

20 Photo/Ion Response Fire Test Room Beam 1 OBS (%/ft) Non-Flaming Tests Bread Bread Bread Nylon Carpet Polyisocyanurate Foam Polystyrene Ponderosa Pine Ponderosa Pine Ponderosa Pine Ponderosa Pine Ponderosa Pine PU Foam PU Foam PU Foam 5 Alarm Trigger Range PU Foam + cotton PU Foam + cotton PU Foam + Poly 0 PU Foam + Poly 0.0E E E E E E E+05 Σ (n i d 3 i ) p/20

21 Photo/Ion Response Fire Test Room Beam Flaming Tests Coffee Maker Coffee Maker Douglas Fir Douglas Fir Douglas Fir Douglas Fir Heptane/Toluene OBS (%/ft) Heptane/Toulene Heptane/Toluene Newspaper Newspaper Nylon Carpet Nylon Carpet Nylon Carpet PU Foam PU foam + cotton/poly PU Foam + cotton/poly 0 PU Foam + cotton/poly 0.0E E E E E E E+05 Σ(n i d 3 i ) p/21

22 Photo/Ion Response Fire Test Room Analog Beam Non-Flaming Tests Bread Bread Analog Photo Signal Change Bread Nylon Carpet Isocyanurate Foam Polystyrene Foam Ponderosa Pine Ponderosa Pine Ponderosa Pine PU Foam PU Foam PU Foam PU Foam + cotton PU Foam + poly 0 PU foam + poly 0.0E E E E E E+05 Σ(n i d 2 i ) p/22

23 Photo/Ion Response Fire Test Room Analog Beam Flaming Tests Analog Photo Signal Change Coffee Maker Coffee Maker Douglas Fir Douglas Fir Douglas Fir Heptane/Toluene Heptane/Toulene Heptane/Toluene Newspaper Newspaper Newspaper Nylon Carpet Nylon Carpet Nylon Carpet PU Foam PU Foam + cotton/poly PU Foam + cotton/poly PU Foam + cotton/poly 0.0E E E E E E+05 Σ (n i d i 2 ) p/23

24 Particle Size Influence on Sensing Technology Obscuration ~ d 3 Relative Signal Sensitivity Physics of ionization technology is linearly responsive to particle size. Physics of light-based technologies are more responsive to larger particles than smaller particles. Scattering ~ d 2 Ion ~ d d, Particle Size p/24

25 STP Activities Improve alarm/detector response New polyurethane smoldering, and flaming tests Adjust obscuration base Adjust time base Nuisance alarm issues Spike values Spike duration Gases of combustion Marking p/25

26 Development: Flaming & smoldering polyurethane tests Develop new flaming and smoldering polyurethane (PU) foam fire tests to compliment existing UL 217 and 268 tests. Increase available egress time for non-specific fires by expanding alarm responsiveness to other smoke signatures. Rationale Flaming PU foam generates smaller smoke particles than the current fire tests. Synthetic materials generate greater heat and smoke release rates than natural materials. Prevalence of PU foam in residential settings (mattresses, upholstered furniture, etc.). p/26

27 Standard Foams Currently Used Product Test Method Foam Test Material Description Smoke detectors Upholstered furniture Residential sprinklers EN 54-7, ISO ASTM E 1353, CPSC 1634 CA TB117+, CPSC 1634 UFAC UL 1626 Soft polyurethane foam - No fire retardant - Density: c. 20 kg/m 3 SPUF: Polyurethane foam - No inorganic fillers or FR - Density: 28.8 ±1.6 kg/m 3 (1.8 ±0.1 lb/ft 3 ) SFRPUF: Flame-retardant polyurethane foam - Density: 22.4 ±1.6 kg/m 3 (1.4 ±0.1 lb/ft 3 ) Polyurethane foam - No inorganic fillers or FR - Density: 24.0 ± 1.6 kg/m³ (1.5 ± 0.1 lb/ft³) Polypropylene oxide polyol, polyether foam - Density: kg/m 3 ( lb/ft 3 ) - PHRR at 30 kw/m 2 : 230 ±50 kw/m 2 - HOC at 30 kw/m 2 : 22 ±3 kj/g p/27

28 Scenario Development Task Objectives: Investigate influence of scenario variables on combustion products. Develop smoke particle size and gas effluent data on the scenarios. Test Parameters: Variables Foam density Sample size & shape Heating method Output Smoke build-up rate p/28

29 Flaming Fire Scenarios Goal: Flaming foam test that achieves obscuration levels similar to the UL 217 flaming tests in a comparable time frame. Potential Scenarios: EN 54-7 TF 4 flaming foam test Variations in foam density, sample size & shape, ignition point p/29

30 Smoldering Fire Scenarios Goal: Smoldering foam test that: Achieves 10 %/ft obscuration at 45 min. Achieves %/ft obscuration by 60 min. Avoids settling/stratification (test < 75 min.). Potential Scenarios: Radiant panel: Heat from sample top surface Hot plate: Heat from sample bottom surface Cigarette ignition: Heat from sample top surface but covered Hot wire: Heat from sample center p/30

31 Flaming Fire Scenarios Variables: Foam density Sample size & shape Ignition point 2 step burning process: Flame front Molten sample Completed: 26 Calorimeter tests 22 Fire Room tests Flame-out ranged from 260 to 2129 s 10 %/ft Obs reached in 85 to 1540s & never p/31

32 Polyurethane Flaming Test Sample p/32

33 NFPA 72 Chapter 11 Task Group Activities Test method variability Tenability issues 3 foot visibility 20 foot visibility p/33

34 Media Coverage Photoelectric/Ionization Alarms Test demonstrations in question Is there a hazard? Earliest possible warning New vs. existing construction No scientific study shows superiority of one technology over another when installed per NFPA 72. Not measuring the quality of smoke can lead to misleading conclusions. The movement of smoke in a building is a complex issue p/34

35 Recommendations The responsiveness of smoke alarms depend upon a number of factors including the type of fire (smoldering, flaming), the chemistry of materials involved in the fire, and the color of the resulting smoke. Both ionization and photoelectric type smoke alarms provide adequate response to these factors but their sensitivity to them varies. Therefore, several fire safety organizations recommend a consumer utilize both ionization and photoelectric technology, or another technology with similar performance characteristics, in their home smoke alarm systems to permit the longest potential escape times for nonspecific fire situations. p/35

36 Recommendations Installing Listing products as follows: 1. as described by the manufactures instructions 2. as required by the minimum requirements of NFPA 72 Reduces ones risk to lose of life, or injury resulting from a nonspecific fire. Deviating from these two simple steps can cause you to lose the benefit of early warning from your fire alarm system. p/36

37 7.1 Smoke Detector Performance QUESTIONS Paul E. Patty, x42752 p/37