RESEARCH AND DEVELOPMENT OF CARBON MONOXIDE FIRE DETECTION

1
RESEARCH AND DEVELOPMENT OF CARBON MONOXIDE FIRE
DETECTION

• Written by
• Peter Lackey
• UK Fire Marketing Manager
• ADT Fire and Security
• Presented by
• Jason Mather
• ADT Fire and Security

2
ASSUMPTIONS OF SMOKE DETECTION

• That smoke will travel from the seat of the fire
  to the detector
• That the fire will produce smoke in sufficient
  quantity to activate the detector
• That the detector will activate in sufficient
  time for effective evacuation or other actions to
  take place

3
SEARCHING FOR ALTERNATIVES

• The presence of Carbon Monoxide (CO) in unwanted
  fires is well known
• CO is either the primary cause of, or a major
  contribution to fire deaths due to disorientation
  and narcosis that accompanies inhalation
• CO is an early indicator of fire

4
FIRE TESTS

• Smoke detector test fires aim to provide a
  repeatable performance comparison for smoke
  detectors
• They are unsuited for heat and flame detectors
• Smoke detector laboratory test fires are
  unrepresentative of real fire scenarios
• CO fire detection possibilities required more
  realistic fire scenarios

5
EARLY TESTING OF CO FIRE DETECTORS

• Ambient background levels of CO must be known
  and distinguishable from levels produced in the
  early stages of a fire
• Air quality studies identify levels in various
  building types and geographical locations
• Normal levels are well below 10ppm
• Rooms with heavy smokers or close to a source of
  air pollution still remain below 32ppm

6
EARLY TEST CONCLUSIONS

• Most fires that are started with a flame follow a
  similar fire development pattern
• Fire appears as several distinct though related
  phenomena
• Pyrolysis
• Smouldering
• Flaming
• How a fire is lit makes a difference to how it
  burns and the ratio of combustion products

7
NEXT STAGE DETAILED TESTING

• Fires in confined areas (cleaners cupboards,
  store rooms)
• Fire in wardrobe with clothing rags
• Fires in soft furnishings
• Cloth covered flame retarded polyurethane foam
• Escape corridors
• Ship test rig
• Warehouse type rig
• Office rig

8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
FACTS ABOUT CARBON MONOXIDE

• Colourless
• Odourless
• Toxic gas
• A product of incomplete combustion

13
Concentration of CO in Air 9 ppm The maximum
allowable concentration for short term
exposure in a living area 35 ppm Maximum
allowable for continuous exposure in any 8 hour
period 200 ppm Maximum concentration allowable
at any time. Slight headaches, dizziness,
nausea after 2 - 3 hours 400 ppm Frontal
headaches within 1-2 hours, life threatening
after 3 hours. 800 ppm Dizziness, nausea and
convulsions within 45 mins. Unconsciousness
within 2 hours. Death within 2-3 hours 1600
ppm Headache, dizziness and nausea within 20
mins. Death within 1 hour 3200 ppm Headache,
dizzines and nausea 5-10 mins. Death 30 mins 6400
ppm Death 10-15 mins 12,800 ppm Death 1-3 mins
14
WHEN AND WHERE TO USE CO FIRE DETECTORS

• Slow, smouldering fires (typical of cigarette
  ends in soft furnishings)
• Sleeping accommodation (hospitals, cruise
  liners, halls of residence, sheltered
  accommodation, nursing homes, hotels)
• Corridors and escape routes (mix of CO and
  optical)
• Large open or awkward areas (atria, warehouses,
  holds)
• Close confined cupboards and storage areas
• Areas that are environmentally unsuitable for
  smoke detection (cooking areas, dirty or dusty
  environments etc.)
• Heritage applications

15
UNSUITABLE APPLICATIONS

• Fires with no Carbon Monoxide
• Risk of fast burning chemical fires
• Duct air sampling
• Light bulbs and faulty electrical cable
  (pyrolysis)

16
OTHER BENEFITS OF CO FIRE DETECTION

• Versatility of siting
• Resilience to false alarms
• Environmentally friendly
• Long life span

17
CO FIRE DETECTION AND BRITISH STANDARDS

• Proposed changes to BS5839 states
• CO fire detectors may be used to protect any of
  the following areas
• Where heat detectors would be used except where
  flammable liquids are the principal hazard
• Rooms opening onto escape routes for an L3
  system
• All areas of an L4 system (with restrictions)
• Any area where a smoke detector would be
  acceptable

18
Co Detection and BS5839Pt1 2001

• Effective From Sept 2002
• and then a
• 9 month running in period

19
Types of Detectors

• Heat
• Smoke
• Combustion gas
• I/R,U/V radiation

20
Combustion Gas Detectors

• Respond to Smouldering fires
• Incomplete combustion,e.g. Co
• Co diffuses, spreads quickly,evenly
• Lifetime 5-7 years

21
Choice of Detector

• Speed of response
• Minimal False alarms
• Nature of hazard
• Cost
• Maintenance