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.