Retrotec FanTestic Integrity (ISO) - Manual (Page 25)

rev-2014-10-27
Page 25 of 50
©Retrotec Inc. 2012

“Calculate Hold time result using:”
Select which type of fire suppression system model will be assumed for calculation of the
hold time.
There are three options, defined according to how the agent behaves after a discharge in
the enclosure:
“Descending Interface “– Agent is discharged at near-ceiling level into the enclosure. An
‘interface’ with a constant concentration (known as the Initial Concentration) descends from
the discharge level as gas leaves the enclosure through leaks. The time it takes for this
‘interface’ to reach the Minimum protected height is defined as the “hold time”.
“Continuous Mixing” – Agent is discharged at near-ceiling level into the enclosure. Fans
circulate gas throughout the room, resulting in a uniform agent concentration. This
concentration begins at Initial Concentration and reduces until it eventually reaches the
specified Minimum Concentration. The time it takes for the Initial Concentration to reach
the Minimum Concentration is defined as the “hold time”.
“Extended Discharge “ – An initial agent discharge achieves the Design Concentration over a
short period of time, which is followed by a second Extended discharge rate (actual) from
another supply of agent in order to maintain at least the Design concentration for a desired
duration. By measuring the enclosure leakage, the agent loss rate can be calculated, which
is calculated as the Extended discharge rate (required). The Enclosure Integrity Test passes
if the Extended discharge rate (actual) is greater than the Extended discharge rate
(required).

“Agent”
Select which agent is used for the enclosure’s fire suppression system.

“Agent quantity by”
Enter the agent quantity and choose whether you are entering agent mass or just entering
the agent’s initial concentration directly. The agent mass can be found on a label on the
bottles containing the agent; if you have both the agent mass from the bottle and an initial
concentration specification, it is advised to use the agent mass. Users of INERGEN or other
IG-541 can enter Agent quantity by volume since they may know the quantity as volume.

“mass” – calculated and displayed if agent quantity is not entered as mass