Building Research Note

Transcription

1 Ser THl R92 no, 2h3 em 2 BDC National Research Conseil national 19 Council Canada de recherches Canada Institute for lnstitut de Research in recherche en Construction construction Building Research Note Measurements and Observations Made during Residential Sprinkler Demonstrations BRN 243

2 MEASUREMENTS AND OBSERVATIONS MADE DURING RESIDENTIAL SPRINKLER DEMONSTRATIONS *? by I. Oleszkiewicz Fire Research Section Institute for Research in Construction BRN 243 ISSN Ottawa, April Research Council Canada Serving the construction industry IRC Au service de la construction

3 ABSTRACT Measurements and observations made during demonstration tests of resideri~ial sprinkler systems, conducted in Charlottetown, Prince Edward Island,',in June 1984, are presented. '+2 Ce document fait 6tat des mesures et observations faites lors dpessais de d6monstration d'extinct~urs automatiqyes pour habitations men& en juin Charlottetown, 3 1'IleduPrinceEdouard. INTRODUCTION Statistics show that most fire fatalities occur in residential fires. The low ceiling heights and the small size of compartments in the typical home cause the hot fire gases to descend quickly to below eye level. An obvious solution to the problem is the early detection and suppression of the fire. The use of smoke detectors has decreased the number of residential fire fatalities, but detection alone is not sufficient. It cannot save lives if the occupants of the building are incapacitated due to age, disability or other factors. Traditional sprinklers have proven unsuccessful, due to their slow response time, in providing life safety for the occupants of the compartment of fire origin. Fast response is important, but so is the capability of the sprinkler to discharge a sufficient quantity of water in the right spray pattern from an ordinary household water supply. A new type of sprinkler, referred to as the residential sprinkler, has been developed to meet the needs of residential buildings. The Institute for Research in Construction, National Research Council o$ Canada, agreed to participate in two demonstration tests of residential sprinkler systems in Charlottetown, P.E.I., in June The tests had been devised jointly by manufacturers of fire protection equipment and by fire protection authorities. The objectives of the demonstration tests were: i) to show the ability of residential sprinklers to extinguish a fire before conditions in the room of fire origin became untenable; ii) to demonstrate the suitability of plastic piping for use in residential sprinkler systems; iii) to demonstrate the operation of an "intelligent" fire alarm system. Although the tests were primarily for demonstration purposes, useful data were collected concerning the performance of residential sprinklers. TEST FACILITY The test facility consisted of two rooms built adjacent to the Fire Fighters Training Tower (Figure 1). The interiors of the rooms were

4 :?. o SPRINKLER 8 PRESSURE GAUGE 2 THERMOCOUPLE THERMOCOUPLE LOCATION ROOM NO. 1 1 AT THE SIDEWALL S PR I NKLER m ABOVE THE FLOOR m ABOVE THE FLOOR m BELOW THE CEILING 5 AT THE SIDEWALL SPRINKLER ROOM NO. 2 1 TO 4 AT THE PENDANT SPRINKLERS m ABOVE THE FLOOR m ABOVE THE FLOOR m BELOW THE CEl Ll NG m ABOVE THE FLOOR, 0.1 m FROM THE WALL Figure 1. Test setup

5 3 finished with gypsum board painted with latex paint; the floors were bare concrete. A c;losedcircuit TV with monitors was installed in the tower and a nearby t+aining centre. V SPRINKLER INSTALLATIONS Two types of sprinklers, both having a temperature rating of 60 C (140 F) were installed: horizontal sidewall residential sprinklers in Room 1, and pendant residential sprinklers in Room 2. Figure 1 shows the distribution of the sprinklers. Plastic piping of 25.4 mm (1 in.) nominal diameter, made from either chlorinated PVC (poly(viny1 chloride)) or Poly B (polybutylene), was used. The pipes were exposed. FIRE ALARM SYSTEM The fire alarm system consisted of 8 addressable ionizationtype smoke detectors in each room (giving a total of 16 detectors) with a microprocessorcontrolled central unit. The sensitivity of the detectors could be adjusted individually from the keyboard of the control unit. INSTRUMENTATION During the tests, the air temperature and CO level in the room, and the pressure and water flow rate in the sprinkler piping were measured. The vertical distribution of temperature was monitored by bare 'thermocouples fixed at 915 mrn (3 ft), and 1525 mm (5 ft) above the floor and 75 mm (3 in.) below the ceiling. Other thermocouples were located close to the sprinklers. The CO level was measured using a sampling set with an air pump and a Draeger device (chosen because of its portability). Air samples were taken 1525 mm (5 ft) above the floor. Water pressure was measured with a pressure gauge at a point just before the burn room. The flow rate and total quantity of water were measured using a Signet paddlewheel flowmeter/accumulator. The flowmeter and all the thermocouples were automatically read and recorded by a data logger. Other data, together with sprinkler activation times, were recorded manually. The smoke detectors were not monitored individually because of the limited scanning speed of the data logger. FIRE SCENARIOS Six trial and two demonstration burns, simulating fires in health care and hotel rooms, were carried out. The trial fires were conducted in order to establish proper scenarios for the demonstration tests.

6 4 To reduce the testing time, flaming fires were chosen. A wastepaper basket filled with crumpled newspaper was used as the source of fire. The flames issuing from the basket ignited a nearby piece of furniture (bed or The arrangement of furniture during the demonstration tests is shown in Figure 1: it is a reproduction of the arrangement used during Trial * RESULTS Trial Test 1 i n Room 1 and Trial Test 1 in Room 2 were conducted before the instrumentation was completely installed. Figures 2 to 7 show air temperature vs. time at the thermocouple locations during the two demonstration tests and the four trial tests for which instrumentation was available. Activation times for the sprinkler and the first smoke detector are indicated on the time axis. Trial Test 2, Room 1 (Figure 2) The fire was very small. The sprinkler at location 5 activated 48 seconds after ignition and extinguished the fire almost immediately. The air temperature remained low during the test. The CO level, however, reached 8000 ppm one minute after ignition. The water pressure was 290 kpa (42 psi) and the flow rate was 1.37 L/s (21.7 U.S. gpm). The first smoke detector activated 17 seconds after ignition. l ~ l ~ l ~ l ~ l ~ l ~ l ~ " 120 W C C v SPRINKLER v SMOKE DETECTOR 1 5 THERMOCOUPLE LOCATIONS v 2 v TIME, Figure 2. Air temperature vs. time; Trial Test 2, Room 2 s

7 Trial Test 3, Room 1 (Figure 3) The fire grew bigger and lasted longer than in the previous test. The sprinkler at location 5 activated 101 seconds after ignition. The gas temperature was higher than during the previow test, but not sufficiently high to cause flashover. The CO level remained low. The water pressure was 160 kpa (23 psi) and the flow rate was L/s (31.5 U.S. gpm). The first smoke detector activated 107 seconds after ignition. l ~ l [ ~ ~ Il I, I I l I I 1 l l i v SPRINKLER v SMOKE DETECTOR 1 5 THERMOCOUPLE LOCATIONS TIME, s Figure 3. Air temperature vs. time; Trial Test 3, Room 1 $rial Test 2, Room 2 (Figure 4) Because of the arrangement of the furnishings and their high combustibility, and the use of sprinklers with a temperature rating higher than that required, the fire was vigorous and gas temperatures were high. The sprinkler at location 3 activated 128 seconds after ignition and promptly extinguished the fire. The CO level was not recorded. The water pressure was 290 kpa (42 psi) and the flow rate was 1.4 L/s (22.2 U.S. gpm). The first smoke detector activated 20 seconds after ignition. Trial Test 3. Room 2 (Figure 5) The arrangement of the furnishings was modified. A highly combustible privacy curtain, used in the previous test, was not reinstalled. Sprinklers with a temperature rating of 60 C were used. The fire developed more slowly than during the previous test. Two sprinklers activated (locations 2 and 3) and suppressed the fire before the eyelevel gas temperature (thermocouple 6) reached 75OC. The sprinkler at location 2 activated 76 seconds after ignition, followed a few seconds later by the sprinkler at

8 ?v SPRINKLER r SMOKE DETECTOR 17 THERMOCOUPLE TIME, s Figure 4. Air temperature vs. time; Trial Test 2, Room v SPRINKLER 120 SMOKE DETECTOR THERMOCOUPLE TIME, s Figure 5. Air temperature vs. time; Trial Test 3, Room 2

9 location 3. The following CO levels were recorded: 0 pprn after 30 seconds, 0 pprn after 2 minutes, 500 pprn after 3 minutes, and 300 pprn after 4 minutes. The water pressure was 324 kpa (47 psi) and the flow rate was 1.57 L/s (24.8 U;S. gpm). The first smoke detector activated 30 seconds after ignition. X Demonstration Test, Room 1 (Figure 6) The fire development was similar to that during Trial Test 3 in Room 1 except for a slower start which was caused by a difference in the randomly arranged ignition source (wastepaper basket with crumpled paper). The sprinkler at location 5 activated 3 minutes after ignition. The following CO levels were recorded: 0 pprn after 1 minute, 150 pprn after 3 minutes, and 300 pprn after 4 minutes. The water pressure was 269 kpa (39 psi) and the flow rate was 1.63 L/s (26 U.S. gpm). The first smoke detector activated 34 seconds after ignition. Several people remained inside the room until the fire was extinguished. They reported no untenable conditions, although they experienced some discomfort due to smoke and water spray. They stressed that they did not feel hot, although the temperature reached lll C at the 1525 mm level (Figure 6, thermocouple 3). l ~ l ~ l ~ l ~ l ~ l ~ v SPRINKLER v SMOKE DETECTOR 1 5 THERMOCOUPLE LOCATIONS v v l 1 ~ ~ ~ TIME, s Figure 6. Air temperature vs. time; demonstration test, Room 1 Demonstration Test, Room 2 (Figure 7) The fire development was similar to that during Trial Test 3 in Room 2. Only one sprinkler activated (at location 3), 2 minutes after ignition. The following CO levels were recorded: 0 pprn after 1 minute, 200 pprn after

10 2.5 minutes, 400 ppm after 3.5 minutes, and 300 ppm after 5 minutes. The water pressure was 324 kpa (47 psi) and the flow rate was 1.6 L/s (254 U.S. gpm). The first smoke detector activated 19 seconds after ignition. u V SPRINKLER SMOKE DETECTOR 1 7 THERMOCOUPLE v TIME, s Figure 7. Air temperature vs. time; demonstration test, Room 2 SUMMARY The purpose of the tests was to demonstrate new sprinkler technology in action. The test conditions were chosen to be appropriate for demonstration purposes rather than to yield information for research. Nevertheless, it is considered desirable to report what was measured and observed as there is little published information on the early stage of fire development coupled with the dynamic response of residential sprinklers. The reports from people exposed to the fire environment in Room 1 indicate that the National Fire Protection Association tenability criterion for temperature, selected as 65OC (l), is conservative for short exposures. ACKNOWLEDGEMENTS These tests were carried out under the auspices of the International Association of Fire Chiefs. Participants in these tests included the Canadian Automatic Sprinkler Association, Canadian Fire Alarm Manufacturers Association, Bow Plastics Ltd., B.F. Goodrich Chemical Group and Grinnell Fire Protection Systems Co. Ltd. The author gratefully acknowledges the technical assistance provided by J.W. MacLaurin and R.C. Monette, who participated in the tests in

11 Charlottetown, and J.E. graphs. Berndt, who processed the data and prepared the 1. Cot6, Arthur E., "Field Test and Evaluation of Residential Sprinkler Systems: Part 11", Fire Technology, Vol. 20, No. 1, February 1984, p. 48.