For a gas extinguisher system to work properly, the protected space must be sufficiently airtight.
According to current standards, gas extinguisher systems must normally have their gas concentrations measured to check that the appliance complies, works properly and is effective when triggered.
However, tests to measure gas concentrations are still relatively costly and difficult to implement (space occupied, passages and flushing out the gas after conducting the tests, etc.).
These gas concentration measurements can be substituted with fan tests which involve setting up ventilators at one or several doors in a room.
The ventilators over and under-pressurise the room, while pressure gauges gather all the data to identify how the extinguisher gas behaves (e.g. the height of the air-gas interface over time) in the room during the permeation period.
In some cases, the test findings can even lead to guidance on ventilation methods during permeation times, based on the type of gas and fire load levels.
This is an essential and necessary test to ensure a gas extinguisher system is both correctly-proportioned and efficient, as well as to certify that it works properly.