M E M O R A N D U M. NFPA Technical Committee on Fire Tests. NFPA 252 First Draft TC FINAL Ballot Results (F2016)

Transcription

1 National Fire Protection Association 1 Batterymarch Park, Quincy, MA Phone: Fax: M E M O R A N D U M TO: FROM: NFPA Technical Committee on Fire Tests Kelly Carey, Project Administrator DATE: June 10, 2015 Subject: NFPA 252 First Draft TC FINAL Ballot Results (F2016) According to the final ballot results, all ballot items received the necessary affirmative votes to pass ballot. 29 Members Eligible to Vote 5 Members Not Returned (J. Burns, S. Dillon, M. Janssens, D. Sheppard, K. Sumathipala) 20 Members Voted Affirmative on All Revisions 4 Members Voted Negative on one or more Revisions (F. Alfawakhiri, B. Badders, M. Hirschler, D. Sloan) 0 Members Abstained on one or more Revisions The attached report shows the number of affirmative, negative, and abstaining votes as well as the explanation of the vote for each first revision. There are two criteria necessary for each first revision to pass ballot: (1) simple majority and (2) affirmative 2 /3 vote. The mock examples below show how the calculations are determined. (1) Example for Simple Majority: Assuming there are 20 vote eligible committee members, 11 affirmative votes are required to pass ballot. (Sample calculation: 20 members eligible to vote 2 = = 11) (2) Example for Affirmative 2 /3: Assuming there are 20 vote eligible committee members and 1 member did not return their ballot and 2 members abstained, the number of affirmative votes required would be 12. (Sample calculation: 20 members eligble to vote 1 not returned 2 abstentions = 17 x 0.66 = = 12 ) As always please feel free to contact me if you have any questions.

2 NFPA 252 TECHNICAL COMMITTEE ON FIRE TESTS - FIRST DRAFT BALLOT - FINAL RESULTS FR-2, Section No , See FR-2 FR-3, Section No , See FR-3 Page 1 of 9

3 FR-4, Section No. 2.4, See FR-4 FR-5, Section No , See FR-5 Affirmative 20 Negative 4 Page 2 of 9

4 Dwayne E. Sloan Marcelo M. Hirschler Barry L. Badders, Jr. We are voting negative for this revision to revise the starting clearance prior to testing from 3/8 inch to 3/4 inch. as there is a lack of test data to determine whether doors previously evaluated would or would not be impacted by this change. I agree with the comments by Dwayne Sloane and Barry Badders. The increased gap at the bottom of the door is a significant change making the test less severe by allowing a higher amount of cooling air across the sill and lower parts of the frame. Farid Alfawakhiri I agree with negatives by Sloan and Badders FR-10, Section No , See FR-10 FR-11, Section No , See FR-11 Page 3 of 9

5 Affirmative 22 Negative 2 Barry L. Badders, Jr. The last clause of the last sentence means the neutral pressure plane has to be within 3 ft of all pressure probes. Better to change "any" to "a" so it reads "...3 ft in height from a pressure probe location." Farid Alfawakhiri I agree with the negative by Badders FR-8, Section No , See FR-8 Page 4 of 9

6 FR-12, Section No , See FR-12 Affirmative 21 Negative 3 William E. Koffel I concur with the ballot comments submitted by Barry Badders. Page 5 of 9

7 Barry L. Badders, Jr. The IBC states that imposition of positive pressure is to be initiated after 5 min into the test for side hinged swinging doors (IBC 2015, ). This is consistent with the requirements of ISO and EN opening protective tests as well. The proposal increases the severity of the test beyond what is required by regulations and comparable international standards. No evidence has been produced that suggests that opening protectiveness have failed to perform their intended function in fires due to positive pressure developing in the very early stages of a fire. Since the code requirement specifically states that the neutral pressure plane is to be established at 40 above the sill after 5 min, the implication is that control of furnace pressure at any prescribed level is not necessary for the first 5 minutes of the test. For nearly 100 years of fire testing history this has been interpreted to mean that the neutral pressure plane should be maintained at the top of the assembly. An important reason for not requiring imposition of a specific pressure requirement during the early stages of a fire test is that this is a very unstable period where the furnace temperature is increased from room temperature to 1000 F. During this startup phase, conditions change rapidly and constantly. Combustibles in the assembly will typically ignite in 2-3 minutes and necessitate substantial changes in fuel input to avoid overshoot of the time-temperature curve. Burn out of combustible material requires significant rapid increases in fuel input to maintain temperature. During this period naturally drafted furnaces develop increasing draft while assembly movement, expansion and deflection can substantially change the flow of air or gas into or out of the furnace. These factors all affect the furnace pressure in unpredictable and often substantial ways. Attempting to tightly control the pressure during this chaotic period also affects the furnace temperature and can result in less precise temperature control. After the initial 5 minute start-up period, the system tends to be much more stable and furnace pressure and location of the neutral pressure plane can be reasonably well controlled. Many door assemblies require intumescent seals to prevent flames and hot gases igniting combustible material on the unexposed face of the assembly. These intumescents require heating to react which takes at least a few minutes. It seems possible that under the proposed procedure the seal may not form quickly enough to prevent ignitions. Thus, some products that obtained listings under the current method may be unable to pass the revised test. In addition, if testing under positive pressure from the beginning of the test is important to better simulate real fire conditions for side-hinged swinging doors, why wouldn t the same be for all other opening protectives? Should sliding, rolling steel and elevator doors also be required to be tested under positive pressure? Neither UL 263 nor ASTM E119 specify the furnace pressure for testing walls or horizontal assemblies. UL 1479 and ASTM E814 for penetration seals do specify positive furnace pressure, but exempt the first 5 (UL 1479) or 10 (E814) minutes of the test. E814 includes a detailed discussion of the issue in Appendix X1 X1.5. Of course these standards are designed to test the sealing capability of subject systems which clearly requires a positive pressure differential to evaluate. This also makes sense in that most fire wall penetrations are located near ceiling level where positive pressure is most significant. This change would almost certainly invite close scrutiny of the furnace pressure data included in test reports. Inevitable significant excursions from the presumed ideal case of neutral pressure at 40 from the sill for doors or 1/3 the height of windows will undoubtedly lead to concerns regarding the validity of the test and compliance determinations. Farid Alfawakhiri I agree with the negative by Badders Page 6 of 9

8 FR-13, Section No , See FR-13 Affirmative 22 Negative 2 Barry L. Badders, Jr. The only rational is to support the proposed pressure change in FR sec intervals are not necessary. Farid Alfawakhiri I agree with the negative by Badders FR-6, Section No , See FR-6 Page 7 of 9

9 FR-14, Section No. B.12.2, See FR-14 Affirmative 22 Negative 2 Barry L. Badders, Jr. There is no justification in increase the severity of the test via the furnace pressure. The scope of the document states "standardized fire and hose stream test", not " fire conditions." In "" fires there are many variables that affect the rate of fire growth and how pressure might develop. These include room size (volume, ceiling height), fuel load, size, nature and location of the ignition source, ventilation, height above ground, wind conditions, finishes, presence and function of suppression systems, etc. The studies that provided the basis for the original change to positive pressure fire door testing were based on large scale experiments (John Gus Degenkolb) which showed that in closed rooms under post flashover conditions, the neutral pressure plane tended to stabilize at around 1/3 of the room height. The 40 above the sill level criteria was derived from this data based on a 10 foot ceiling height typical of commercial buildings. Tests conducted by Simon H. Ingberg of the National Bureau of Standards in the 1920 s of buildings (15 x 30 and 30 x 60 with 9 foot ceilings) with moderate to large fire loads and quite intense ignition sources indicated that it typically took between 30 minutes and 1 hour to reach flashover. Data from these experiments were instrumental in establishing the validity of the time-temperature curve still in use. Farid Alfawakhiri I agree with the negative by Badders Page 8 of 9

10 FR-7, Section No. C.1.1, See FR-7 Page 9 of 9