Smoke Alarm Performance in Kitchen Fires and Nuisance Alarm Scenarios
Thomas G. Cleary, Artur A. Chernovsky
Tests were conducted to assess the performance of various residential smoke alarms to kitchen fires and nuisance alarm cooking scenarios. A test structure representing a kitchen, living room and hallway was constructed to conduct the tests. Eight different residential smoke alarms types, two photoelectric models, two ionization models, two dual sensor models, and two multi-sensor, intelligent models were used in this study. The data gathered provided insight into the susceptibility of alarm activation from exposures to typical cooking events and alarm times for actual kitchen fires. The effects on the type of alarm, and its distance from the cooking activity or fire were examined. Combustible materials typically found on a counter top can spread flames to overhead cabinets, and a single empty 0.6 m wide 1.0 m tall cabinet can produce a peak heat release rate nearly sufficient to flashover a small room. A protective metal barrier on the bottom and side facing the range tended to limit the spread of flames to the cabinet and reduce the heat release rate. All smoke alarms responded before hazardous conditions developed. The I1 alarm tended to respond first at a given location. Results show smoke alarms placed at the furthest location may provide less than 120 s of available safe egress time, which suggests a more central alarm location closer to the kitchen for this configuration. Ten cooking activities were examined to determine an alarms propensity to activate to cooking aerosols. In most cases, the propensity to nuisance alarm decreased as the distance from the cooking source increased. Alarms that rely on sensitive ionization chambers (here I1 and D2) experience more nuisance alarm activations across all cooking activities and locations. All alarms except I1 and D2 experienced about the same nuisance alarm frequency across all cooking activities for locations outside the kitchen.