Report of the Performance of a Solid Core Timber Door in a Fire Test using a Standard Heating Regime. By J.P. England and S.A.

Transcription

1 Report of the Performance of a Solid Core Timber Door in a Fire Test using a Standard Heating Regime By J.P. England and S.A. Young

2 1 Report of the Performance of a Solid Core Timber Door in a Fire Test using a Standard Heating Regime By J.P. England and S.A. Young 1999 Warrington Fire Research (Aust) Pty Ltd Disclaimer No warranty of accuracy or reliability as to such information is given, and no responsibility for loss arising in any way from or in connection with errors or omissions in any information provided (including responsibility to any person by reason of negligence) is accepted by Warrington Fire Research (Aust) Pty Ltd or the Building Control Commission or their agents or employees. Copyright This publication is copyright. Apart from any fair dealing for the purposes of private study, research, criticism or review, as permitted under the Copyright Act, no part may be reproduced by any process without permission. Warrington Fire Research (Aust) Pty Ltd PO Box 4282 Dandenong South Victoria 3164 Phone: Fax: wfraust@compuserve.com Building Control Commission Level 27, Casselden Place 2 Lonsdale Street Melbourne Victoria 3000 Phone Fax Internet:

3 2 Introduction At the time of publication of this document, there was only limited information that details the performance of solid core timber doors in fire available in the public domain. The Building Control Commission in Victoria has provided sponsorship to publish the results of a fire test on a solid core timber door. The results reported in this document are extracted from a test which was one of a series undertaken in a research program undertaken by Warrington Fire Research (Aust) Pty Ltd, Lorient Fire Seals and Tyco Grinnell to develop test methods which could provide data useful for performance based fire engineering approaches. Lorient Fire Seals has contributed additional information on air leakage tests on solid core doors, this information is presented in the BCC Manual (England et al (1999)). The results were obtained using one type of solid core timber doorset and there may be some variation in results obtained for other solid core doorsets. Types of Solid Core Doorset AS2688 describes the methods for the construction of solid core timber door leaves. Alternative types of door leaf construction are available in relation to solid core timber doorsets including composite MDF faced strandboard panels. Variations in performance will occur due to variations in the form of construction, materials and adhesives used. The results presented in this document were obtained using one type of solid core doorset and there may be some variation in results had the test being carried out for other solid core doorsets. Exposure of Doorsets Ambient - Cold Smoke Scenarios Applies to (i) doors distant from a fire, where the temperature of the smoke has cooled due to dilution and loss of heat to the structure so that it is close to ambient temperatures; or (ii) Doors to the room of fire origin exposed to a smouldering fire that produces smoke but does not result in a significant rise in the room temperature. Medium - Warm Smoke Scenarios Applies to (i) doors distant from a fire, where the temperature of the smoke has cooled to a temperature of 200 C; or (ii) Doors to the room of fire origin exposed to a small flaming fire that results in the doorset being exposed to a temperature of 200 C. This scenario may be indicative of a sprinkler controlled fire. Hot - Hot Smoke Scenarios Applies to doors exposed directly to a large flaming or fully developed fire. The heating regime can be simulated by the use of AS standard heating regime or the more severe hydrocarbon heating regime. For many applications,

4 3 the standard and hydrocarbon curves can be considered to bracket a large proportion of fully developed fires. Data for a specific type of solid core timber doorset for Ambient and Medium temperature conditions are presented in the associated BCC Manual (England et al (1999)). The following report details the findings for a test on the same solid core doorset exposed to the AS standard heating regime. Fire Test Apparatus & Procedures The test apparatus consisted of a corridor (6m long x 1.8m wide x 2.4m high), one end of which was attached to a wall frame, containing the door frame and leaf, simulating a protected passage in a building. During the fire test, the apparatus was attached to the furnace with the doorset exposed to the furnace conditions. The other end of the corridor was substantially closed, but was fitted with an opening of 100mm diameter to simulate building leakages. Photographs detailing the generalised configuration of the system are shown in Figure 1 to Figure 3. Furnace Wall frame containing solid core door Test Corridor Thermocouple extension cables Data acquisition equipment Figure 1: Side View of Door/Corridor Leakage Test Apparatus

5 4 Video cameras recording test Sealed access panel to corridor 100mm dia pipe to simulate building leakages Figure 2: Rear/Side View of Door/Corridor Leakage Test Apparatus Smoke alarms (optical (L)), ionisation (R) Exit sign, 2.1m high above floor level Thermocouple trees Smoke obscuration measurement apparatus Figure 3: View within the Door/Corridor Leakage Test Apparatus

6 5 The edges of the corridor were sealed with a fire grade mastic and compressed ceramic fibre around the edges in order to reduce the leakage between the frame and the corridor. The apparatus was extensively instrumented. Pressures and temperatures were measured, in addition to the outflow of gases at the end of the corridor. Temperatures were measured by Type K thermocouples, using exposed hot junctions and copper disk with pads where appropriate, around the edges of the door leaf in order to identify leakage in these regions, and in the prescribed positions for a standard fire resistance test. The position of the thermocouples is shown in Figure 4 and illustrated in Figure 5 and Figure B7 B8 B9 C4 C5 C6 C7 C8 150 D9 C9 Door frame 360 B1 B2 360 D8 C B6 D7 B3 B C D6 C D5 B4 B5 D1 110 D4 D3 D Not to Figure 4: Position of Thermocouples on the Door Frame and Leaf (Not to Scale)

7 6 Figure 5: Thermocouples Attached to Door Leaf and Around Door/Door Frame (Pre-test Photograph)

8 7 Figure 6: Thermocouples Attached Around Door/Door Frame (Pre-test Photograph) Indicating the Gas Temperature Measurement Around the Edges of the Door Thermocouple trees were installed within the corridor to measure the temperature distribution along the length at several heights (refer to Figure 7 and Figure 8). The heights at which the temperature were measured were selected based on the following considerations: (i) To provide detailed data near the ceiling level to determine the magnitude of hot gas leakage into the corridor; and (ii) To measure temperatures at locations where tenability criteria may be considered by fire engineering analysis using zone model techniques. Such heights included 2.1m, 1.9m and 1.5m above the floor level.

9 8 1.8m wide 2.4m high 0.5 m 0.5 m 2.0 m 1.3 m 1.4 m door 6 m long Locations of thermocouple trees for corridor temperature measurement Figure 7: Position of Thermocouple Trees in Corridor 0.2 m 0.1 m m 2.1 m 1.9 m 2.4 m 1.5 m 1.0 m 0.5 m 0.45 m 0.9 m 0.45 m Figure 8: Cross-Section through the Corridor Position of Thermocouples within the Corridor at each Location Shown in Figure 7 Smoke alarms, of ionisation and photoelectric type, were installed for the test, to give an indication of the warning provided to occupants in a building in the event of a fire in an apartment, with the general building alarm being raised by detectors located in the corridors. An exit sign was installed to provide an indication of visibility in the corridor; in addition, obscuration measurement devices were installed in order to define a more precise measurement of the reduction in visibility versus time.

10 9 The test construction comprised a single leaf door assembly built into a masonry wall. The door leaf opened towards the furnace. The fire exposed face before the test is shown in Figure 9. Figure 9: Fire Exposed Face of the Door Leaf/Surrounding Construction before Commencement of the Test The separating element was a 140mm thick concrete block wall, 3.22m high x 1.92m wide. A steel door frame was fitted into the opening provided in the wall. The solid core door was 35mm thick and faced with 3mm plywood on each face. The door leaf was approximately 2040mm high by 815mm wide. Gaps were measured of approximately 3mm between the edges of the door leaf and frame during a door survey conducted prior to commencement of the test.

11 10 Results Observations The following is a summary of observations made during the test series: Smoke layer commenced forming in the corridor Approx 4 00 Exit sign above door not visible Approx 5 10 Smoke layer at approximately 2m height Approx 5 15 Very low visibility in corridor 5 45 No Visibility in corridor 6 15 Smoke detector activation Flaming on Door Leaf Approx Note: all times are referenced to the furnace ignition time of the tests. The following frames were captured from the video that recorded the test. It must be noted that positive furnace pressure at the sill of the door was attained at approximately four minutes. The MPEG video files show the process of the smoke filling the corridor within a period of approximately two minutes after establishment of the furnace pressure. Commencement of Test (0 minutes) 2 Minutes Test Duration 3 Minutes Test Duration 4 Minutes Test Duration

12 11 Positive pressure attained at sill for furnace - significant volumes of smoke enter the corridor (4 Minutes, 14 Seconds Test Duration) 5 Minutes Test Duration 5 Minutes, 30 Seconds Test Duration 6 Minutes Test Duration 7 Minutes Test Duration 15 Minutes Test Duration

13 12 Figure 10: Door Leaf after Conclusion of the Test and Removal of the Corridor Apparatus Smoke Obscuration versus Time The smoke obscuration measured during the test is shown in Figure Obscuration in Corridor Versus Time F Solid Core Door, No Intumescent Seals AS Standard Heating Regime Obscuration (%) Time (Minutes) 1.9m obscuration 1.5m obscuration 1.0m obscuration Figure 11: Smoke Obscuration at Various Heights above Floor Level versus Time

14 13 The rapid influx of smoke was associated almost immediately with the establishment of a positive pressure from the furnace being applied to the sill of the door (zero pressure). This took approximately four minutes for the furnace to achieve, however it should be noted that this time is associated with furnace control only and does not have any relationship with the pressure generated from a real fire. The smoke was generated from the door construction alone, the furnace is gas fired and configured to burn with an approximately stoiciometric mixture. A real fire would be expected to generate a much denser smoke than generated by a door burning alone. Furnace Temperature versus Time The heating regime to which the door was subjected was as specified in AS for a standard fire resistance test. The actual furnace temperature and the regime specified in AS are shown in Figure Furnace Temperature Versus Time F Solid Core Door, No Intumescent Seals AS Standard Heating Regime Temperature ( C) Time (Minutes) Average Furnace AS Figure 12: Furnace Temperature versus Time

15 14 Door Leaf Temperatures The temperatures measured on the door leaf during the test versus time are shown in Figure Door Leaf Temperatures Versus Time F Solid Core Door, No Intumescent Seals AS Standard Heating Regime 200 Temperature ( C) Time (Minutes) B1 B2 B3 B4 B5 Figure 13: Door Leaf Temperatures versus Time Gas Temperatures Measured around the Edges of the Door The gas temperatures measured around the edges of the door are shown in Figure 14 to Figure 16. An increase in the gas temperatures can be seen from these Figures to have occurred as the pressure conditions of the furnace were established after approximately four minutes. Leakage of hot furnace gases at specific locations can be seen in Figure 15 and Figure 16 after approximately 9 minutes. The opening of a significant gap at the top of the door, on the latch side after approximately 15 minutes can be interpreted from the temperatures of the thermocouples in this region being close to the furnace temperatures at the same time.

16 Gas Temperatures in the Immediate Vicinity of the Hinge Edge of the Door F Solid Core Door, No Intumescent seals AS Standard Heating Regime 600 Temperature ( C) Time (Minutes) C4 D4 D5 D6 D7 D8 D9 Figure 14: Gas Temperatures in the Immediate Vicinity of the Hinge Edge of the Door versus Time Gas Temperatures in Immediate Vicinity of Latch Edge of Door Versus Time F Solid Core Door, No Intumescent Seals AS Standard Heating Regime Temperature ( C) Time (Minutes) C8 C9 C10 C11 C12 D1 D2 Figure 15: Gas Temperatures in the Immediate Vicinity of the Latch Edge of the Door versus Time

17 Gas Temperatures in Immediate Vicinty of Head of Door F Solid Core Door, No Intumescent Seals AS Standard Heating Regime Temperature ( C) Time (Minutes) C4 C5 C6 C7 C8 Figure 16: Gas Temperatures in the Immediate Vicinity of the Head of the Door versus Time Gas Temperatures Measured in the Corridor An indication of the gas temperatures recorded near the ceiling at 3m from the doorset in the corridor versus time is shown in Figure 17. The temperatures at this height are greatest for the corridor, the temperatures were selected in the centre of the corridor, where the flow of gas within the corridor was considered most stable. The initial increase in temperature can be seen to occur when the required pressure conditions of the furnace were established. 250 Corridor Gas Temperature (25mm from Ceiling) versus Time Thermocouple Tree at Centre of Corridor (3m from Door) F91714 Solid Core Door, No Intumescent seals AS1530.4/ISO 834 Standard Heating Regime 200 Temperature ( C) Time (Minutes) Figure 17: Gas Temperatures in the Corridor, 25mm from the Ceiling, 3m from the Door versus Time

18 17 Discussion It was identified that the furnace pressure was crucial to the results in determining the leakage of the door. Upon establishing a positive pressure differential across the door, with a value of zero at the sill, it could be seen that a tightly fitting solid core door did not prevent the passage of smoke. There was no visibility in the test corridor two minutes after the establishment of the test pressure conditions. Based on the results of the test as indicated by the leakage of gas around the edge of the door, conditions consistent with the spread of fire through the doorset occurred after approximately 15 minutes test duration. The test results presented apply to the specific solid core door only. Based on the work undertaken, important findings were made, however further refinement of the apparatus and procedures are required in order to provide definitive design data to allow fire safety engineers to predict smoke spread associated with leakage through a closed fire or smoke door in a fully developed fire. Conclusion Results from a fire test simulating a tightly fitting solid core door separating an apartment with a fire from a corridor have been presented. Upon establishing a positive pressure differential across the door, with a value of zero Pascal at the sill, it could be seen that a tightly fitting solid core door did not prevent the passage of smoke. The results were obtained using one type of solid core doorset and there may be some variation in results has the test been carried out for other solid core doorsets. Further research is required to establish design data for predicting smoke spread associated with leakage through a closed fire or smoke door in a fully developed fire. Acknowledgements The following parties are acknowledged for their contribution to this test. Co-sponsors in the Solid Core Door Tests: Lorient Polyproducts, in particular, Rob Mann and John Rakic. CSIRO Division of Building, Construction & Engineering at Highett for monitoring smoke obscuration, in particular, Justin Leonard. Vision Systems for monitoring smoke concentration. Warrington Fire Research staff contributing to the test series; namely David Baker, Gino Catania and Robert Lewins.