Room Integrity Testing Terminology
For fire suppression system to work properly, the room must have sufficient
integrity to retain an extinguishing concentration for a specified period after
discharge - usually 10 minutes) if the enclosure can’t adequately hold the
extinguishment the fire may reignite causing further damage. As this is the
predominant cause of failure, the British and International Standard (BS:
ISO14520) requires that a server room integrity
test be conducted on system installation and thereafter
at annual intervals, failure to do so may negate your buildings insurance.
What is a Descending Interface
The fire retardant agent is discharged
from the ceiling –highest point) into the protected enclosure. An ‘interface’
with a constant concentration - known as the Initial Concentration) descends
from the discharge level as gas leaves escapes from the enclosure via air
leakage paths. The time it takes for this ‘interface’ to reach the minimum
protected height such as the top of the server racks is defined as the Hold
time. The time retention time for a Room Integrity Test Pass is usually set at 10 minutes.
What is Continual Mixing
The suppressant Agent is discharged at
near-ceiling level into the enclosure, thereafter fans circulate gas throughout
the room, resulting in a uniform agent concentration. This concentration begins
at initial concentration and lowers until it eventually reaches a specified
minimum concentration. The time it takes for the initial concentration to reach
the minimum concentration is defined as the hold time.
What is an Extended Discharge
Typically extended discharges consist
of an initial discharge for 10 to 60 seconds to get the concentration up to the
design concentration. Then the extended discharge will continue at a lesser
rate. The intention is for the extended discharge to replace the agent that
leaks out of the room. It is assumed that the extended discharge will create
enough turbulence to create a continual mixing situation throughout the
extended discharge period.
We hope the above information has been
helpful, if you require a room integrity test, please contact us now at info@airpressuretesting.net or call us on 07775623464.
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