releasing systems
TRANSCRIPT
Releasing Systems
Rob Mennie
Senior Consultant
Gage-Babcock & Associates Ltd.
Releasing Systems
• What is a releasing system?
‣ System designed to detect a fire
• Causes release of an extinguishing system in
response to the fire
Types of Extinguishing Systems
• Releasing systems may control the
release of:
‣ Sprinklers
• pre-action or deluge, water or foam, water mist
‣ Clean agents
• Inergen, Novec, Co2, FM200
Releasing Systems Concept
• Three elements:
‣ Input – detection
‣ Process – sequence of operation
‣ Output – notification, annunciation, and
release of suppression agents
• Elements are similar to structure of a
building fire alarm system, but different in
detail
More Harm than Good?
• Fire suppression systems sometimes do
more damage than fire
‣ Sprinklers spraying computer equipment or
valuable artifacts
‣ Frozen piping in cold storage facilities
‣ Foam discharge on aircraft being serviced in
hangars
More Harm than Good?
• Damage can result from fire suppression operating in absence of fire
‣ Sprinkler heads provide both fire detection and suppression
‣ Physically damaged sprinklers may discharge water as if activated‣ Damaged piping has the same effect
‣ Even if there is a fire, water may inflict unacceptable damage
The Solution
• Separate fire detection and suppression
activation
‣ Provide electrical detection of fire
‣ Prevent water release if sprinklers or piping
are damaged
‣ Allow for use of systems that do not use water
as a suppression agent
Releasing vs. Fire Alarm Systems
• Releasing systems:
‣ Use fire alarm equipment and components
‣ Do not meet Building Code requirements for
building fire alarm systems
‣ Include functions not found in building fire
alarm systems
‣ Provide detection only in limited area covered
by associated fire suppression system
Codes and Standards
• Fire Alarm System• BCBC CAN/ULC-S524 & CAN/ULC-S537
• Clean Agent Releasing System• no BCBC requirements
• Clean Agent Releasing systems not BCBC-regulated nor mentioned in CAN/ULC-S524‣ Design is based on good engineering practice
• Installation and verification should follow ULC-S524 and ULC-S537 requirements for the systems/components provided
Why Use a Releasing Panel?
• Not all building fire alarm panels are listed
for releasing
• Allows for continuous protection even if
the building system is being serviced
• Less chance of accidental discharge
during inspection of building system
Stand-alone Releasing Panels
• Panels must be listed by ULC for releasing
• Panels normally protect a single hazard
• Panels usually are pre-programmed with
some releasing options
• Some panels are for pre-action systems
and some for clean agent systems
Building Alarm Panels
• Most current panels have releasing
capabilities
• Panel must be listed by ULC for releasing
• Panels may protect multiple hazards for
single panel
• Releasing options normally selectable
through panel software
Input – Detection
• Automatic detection of a fire is based
detection of
‣ heat
‣ Smoke
‣ light from flame
Heat Detection
• Heat detection is used where high-heat-
release fires are expected
• Types:
‣ Spot-type heat detectors
‣ Linear heat detectors (Protectowire)
Spot-Type Heat Detectors
• Spot-type heat detectors are used for area
protection where a ceiling exists to bank
heat
‣ Ex. Cold storage warehouse with pre-action
sprinkler system
Linear Heat Detectors
• Linear heat detectors (Protectowire) are
used:
‣ for detection near fuel sources that do not
have a ceiling to bank heat
‣ where spot-type detectors are difficult to
install
• Warehouse storage racks
• storage freezers
• Conveyor galleries
Smoke Detectors
• Smoke detectors are used where low-heat
release or smoldering fires are expected
• Types:
‣ Spot-type smoke detectors
‣ Air aspirating smoke detectors
Spot-Type Smoke Detectors
• Spot-type smoke detectors are used for
area protection where a ceiling exists and
air currents are limited
‣ Small computer or server room
‣ Electrical rooms
Air Aspirating Smoke Detectors
• Air aspirating smoke detectors are used:• for high value occupancy where expense is
justified
• where greater sensitivity is required
• where spot-type detectors are difficult to install or
service
‣ Large computer rooms
‣ Museums
‣ Atriums
‣ High voltage electrical rooms
Flame Detectors
• Flame detectors are used:
‣ for long range detection in large areas
‣ in outside areas where wind may move
smoke and heat away from detectors
• Petrochemical plants
• Aircraft hangars
Manual Detection
• Manual detection is used as a backup for
automatic detection
• It uses dedicated manual pull stations
‣ Manual pull stations are:
• clearly labeled for suppression agent releasing
• a different color from building pull stations
• at exits for egress from hazard area
Process and Output
Sequence of Operation
• Releasing systems provide more control
over response than building fire alarm
systems
‣ Response:
• is based on a number of detectors or zones
detecting fire
• may be automatically time-delayed
• manually delayed
• provides different stages of action
Pre-action Systems
• Common types of releasing sequences:
‣ Single interlock
‣ Double interlock
Deluge Systems
• Primarily open head sprinklers with
solenoid release by single or cross-zoned
signal
Process and Output
Cross-Zoning
• Cross-zoning:
‣ helps reduce unwanted suppression agent
discharges
‣ divides detectors into two zones
• Agent does not release unless at least one
detector on each of two zones is activated
‣ First zone provides alarm
‣ Second zone provides releasing
Process and Output
Automatic Time Delay
• Automatic time delay:
‣ provides time for occupants to leave the area
‣ is used where suppression agent may be
harmful to human health
‣ provides time for investigation and prevention
of unwanted agent release
‣ provides time for ancillary functions
• air handling
• door closers
Process and Output
Manual Time Delay
• Manual time delay:
‣ uses an abort switch to prevent agent release
while switch is held
‣ provides time for investigation and prevention
of unwanted agent release while switch is
held
‣ can be a mechanical delay in discharge piping
Process and Output
Different Response Stages
• Cross-zoning:
‣ allows for escalating response• First zone activation provides notification to start
personnel response or evacuation
‣ calls fire department
‣ initiates alarm condition on building fire alarm system• Second zone activation provides different
notification signal
‣ releases suppression agent
Interaction with Base Building
Fire Alarm System
• Releasing system must report:
‣ Alarm
‣ Supervisory
‣ Common Trouble
Additional Operations
• Building or Stand-alone systems may:
‣ Operate ancillary functions
• Air handling equipment
• Process equipment
‣ Shutdown equipment in hazard area
‣ Release motorized dampers to
• Seal room for some agents
• Pressure relief for Inergen
Notification Devices
• Device Types
‣ Alarm bells
‣ Alarm horns
‣ Strobe lights
• Signage
‣ Over exit/entrance doors for hazard area
Common Problems
• There are a number of common problems
with:
‣ Releasing system panels
‣ Pre-action sprinkler system releasing
‣ Manual switches
Common Problems with Releasing
System Panels
• Releasing solenoid connected to bell circuit
rather than releasing panel
‣ Not listed for such service
‣ No releasing function if bells are by-passed
• Releasing function located on building fire alarm
panel instead of releasing panel
‣ No suppression agent releasing if building
system out of service
‣ Danger of accidental release during servicing
More Common Problems
• Releasing system not connected to
building fire alarm system
‣ No alarm to other tenants
‣ May not be monitored
Common Problems with Pre-Action
Sprinkler Releasing System
• Cross-zoned detection
‣ Pre-action sprinklers only release water after system
detects fire and sprinkler activates because of heat
‣ If detection is cross-zoned, water will not release until:
1. First zone activates
2. Second zone activates
3. Sprinkler activates
‣ Required cross-zoning exists between electrical
detection and sprinkler, not within electrical detection
More Common Problems
• Missing detectors
‣ Every space containing a pre-action sprinkler
must contain a detector connected to the
releasing panel
• Includes small rooms and closets
• Without this, no water is released (even if
sprinkler operates) because the releasing
panel will not activate if no detector exists in
protected space
More Common Problems
• Abort switch on pre-action sprinkler
system
‣ Water will not be released until sprinkler
activates
‣ If sprinkler activates, water is immediately
required to control fire
‣ Preventing water release is not appropriate
Common Problems with Manual
Switches
• Manual release pull station same as
building pull station
‣ May result in:
• accidental release of suppression agent
• delayed release if occupants do not understand
system operation
More Common Problems with
Manual Switches
• Abort switch is in isolated location
‣ Unless occupant can reach control panel or
communicate with others, he is trapped while
pressing abort switch
• Any questions?
• Thank you for your attention.