Inert gas must discharge 95% within how many seconds for class A-C fires?

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Multiple Choice

Inert gas must discharge 95% within how many seconds for class A-C fires?

Discharge time is the rate at which an inert gas flooding system must release its agent into the protected space to reach the required concentration. For spaces protected against Class A-C fires, the standard target is to achieve 95% of the design concentration within 120 seconds. This timing gives enough gas to spread and mix throughout the space so the fire is effectively suppressed by cooling and by displacing heat and oxygen, while also keeping exposure risk reasonable if occupants are nearby or evacuating. If the discharge were to occur much faster than 120 seconds, it would require a much higher flow and could make uniform distribution more difficult in larger or oddly shaped rooms. If it took longer than 120 seconds, the fire could grow or reignite before the desired concentration is reached. So 120 seconds is a practical balance that supports reliable suppression across typical installations.

Discharge time is the rate at which an inert gas flooding system must release its agent into the protected space to reach the required concentration. For spaces protected against Class A-C fires, the standard target is to achieve 95% of the design concentration within 120 seconds. This timing gives enough gas to spread and mix throughout the space so the fire is effectively suppressed by cooling and by displacing heat and oxygen, while also keeping exposure risk reasonable if occupants are nearby or evacuating.

If the discharge were to occur much faster than 120 seconds, it would require a much higher flow and could make uniform distribution more difficult in larger or oddly shaped rooms. If it took longer than 120 seconds, the fire could grow or reignite before the desired concentration is reached. So 120 seconds is a practical balance that supports reliable suppression across typical installations.

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