The ability for the gaseous agent to be retained in the protected room for an extended period of time is critical to the performance of any total flooding clean agent fire extinguishing system. NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems, requires that a minimum concentration of 85% of the adjusted minimum design concentration be held at the highest level of combustibles for a minimum period of 10 minutes. Those installing these systems are required to perform a Room Integrity Fan Test to assure the protected room will hold the agent for the required period of time. (https://www.orrprotection.com/mcfp/clean-agent-fire-suppression-room-integrity-testing)