When to use: Use this calculator to size the total-flooding clean agent quantity for a protected enclosure per NFPA 2001. Halocarbon agents use W = (V/s)·(C/(100−C)) where s = k₁ + k₂·T is the superheated vapor specific volume at the enclosure temperature. Inert gases (IG-541, IG-55, IG-100) use the logarithmic flooding factor X = 2.303·log₁₀(100/(100−C)). Concentration must equal or exceed the agent's minimum design concentration for the hazard class.
Per NFPA 2001 Annex C, every total-flooding clean agent enclosure must pass a door-fan (room integrity) test. The test measures the equivalent leakage area and predicts the agent retention (hold) time — the design concentration must be maintained at the highest protected height for a minimum of 10 minutes (or the time needed to respond). The agent quantity above assumes the enclosure passes this test; excessive leakage requires sealing the room or increasing agent supply.