NFPA Standard : NFPA 2001 Standard (1996 Edition)

Standard	Comments
1-4.2.7 Where clean agent systems are used, a fixed enclosure shall be provided about the hazard that is adequate to enable the specified concentration to be achieved and maintained for the specified period of time.	Large holes and/or duct leaks can cause "lumps" of air to get pulled in upon discharge. Local reduction in agent concentration may compromise protection.
1-5.1.2.1 Unnecessary exposure to all halocarbon clean agents and their decomposition products shall be avoided. Halocarbon agents for whom the design concentration is equal to or less than the NOAEL shall be permitted for use in normally occupied areas. Halocarbon agents for which the design concentration is greater than the NOAEL shall not be permitted for use in normally occupied areas.
1-5.1.2.2 To maintain oxygen concentrations above 16 percent (sea level equivalent), the point at which onset of impaired personnel function occurs, no halocarbon fire extinguishing agents of concentration greater than 24 percent addressed in this standard shall be used in a normally occupied area.	INERGEN® may be the exception, where oxygen may fall to 12% but the increased CO₂ will increase the breathing rate to compensate.
3-3.2 The area of uncloseable openings shall be kept to a minimum. The authority having jurisdiction can require pressurization/depressurization or other tests to assure proper performance as defined by this standard.
3-3.3 To prevent loss of agent through openings to adjacent hazards or work areas, openings shall be permanently sealed or equipped with automatic closures. Where reasonable confinement of agent is not practicable, protection shall be extended to include the adjacent connected hazards or work areas.
3-3.4 Forced-air ventilating systems shall be shut down or closed automatically where their continued operation would adversely affect the performance of the fire extinguishment agent system or result in propagation of the fire. Completely self-containment recirculating ventilation systems are not required to shut down. The volume of the system and associated ductwork shall be considered as part of the total hazard volume when determining agent quantities.	If not shut down, additional agent must be provided to compensate for losses.
3-7 Duration of Protection. It is important that the agent design concentration not only shall be achieved, but also shall be maintained for a sufficient period of time to allow effective emergency action by trained personnel. This is equally important in all classes of fires since a persistent ignition source (e.g. an arc, heat source, oxyacetylene torch, or “deep-seated” fire) can lead to resurgence of the initial event once the clean agent has dissipated.	This time is usually 10 minutes but this should be considered more carefully. Take into account response time for fire dept. or other personal; the mass of the fuel; the extent of “deep- seated” potential.
4-1.1 At least annually, all systems shall be thoroughly inspected and tested for proper operation by competent personnel. Discharge tests are not required.
4-4 Enclosure Inspection. At least every 12 months, the enclosure protected by the clean agent shall be thoroughly inspected to determine if penetrations or other changes have occurred that could adversely affect agent leakage or indicates conditions that could result in inability to maintain the clean agent concentration, they shall be corrected. If uncertainty still exists, the enclosures shall be tested for integrity in accordance with 4-7.2.3.	There will almost always be cause for a re-test since enclosures always become leakier with time. It is far easier to setup the door fan and retest than to do a detailed inspection to find holes in the enclosures.
4-5.3 Any penetrations made through the enclosure protected by the clean agent shall be sealed immediately. The method of sealing shall restore the original fire resistance rating of the enclosure.	Door fan test will show enclosure is sealed.
4-6.1 All persons who might be expected to inspect, test, maintain, or operate fire extinguishing systems shall be thoroughly trained and kept thoroughly trained in the functions they are expected to perform.	AHJ may ask to see certificate of course completion on door for testing.
4-7.2.2.10 A discharge test is generally not recommended; however, if a discharge test is to be conducted, containers for the agent to be used shall be weighed before and after discharge. Fill weight of container shall be verified by weighing or other approved methods. For inert gas clean agents, container pressure shall be recorded before and after discharge.
4-7.2.3 Review Enclosure Integrity. All total flooding systems shall have the enclosure examined and tested to locate and than effectively seal any significant air leaks that could result in a failure of the enclosure to hold the specified agent concentration level for the specified holding period. The currently preferred method is using a blower door fan unit and smoke pencil. If quantitative results are recorded, these could be useful for comparison at future tests.	This clumsily worded section is usually taken to mean that all clean agent systems must have a door fan test. The quantitative results are used when the enclosure is re-tested.
A-1-6 Do not perform unnecessary discharge testing
A-4-7.2.3 If the authority having jurisdiction wants to quantify the enclosure’s leakage and predicted retention time, Appendix B of NFPA 12A, Standard on Halon 1301 Fire Extinguishing Systems, may be used. Adjustment to the existing formulas must be made to account for differences in gas density between Halon 1301 and the proposed alternate extinguishing agent. Specifically, Equation 8 in paragraph B-2.7.1.4 of NFPA 12A must be modified by substituting the alternate agent’s gas density in (Kg/m³) for the existing value of 6.283, which is the value for Halon 1301. See Appendix B of this Standard.	The formula adjustment is made in the Retrotec software using values supplied by NFPA
All of Appendix B
B-1.1.4 This procedure should not be considered to be an exact model of a discharge test. The complexity of this procedure should not obscure the fact that most failures to hold concentration are due to the leaks in the lower surfaces of the enclosure, but the door fan does not differentiate between upper and lower leaks. The door fan provides a worst-case leakage estimate that is very useful for enclosures with complex hidden leaks, but it will generally require more sealing than is necessary to pass a discharge test.