Smoke Alarm Performance in Kitchen Fires and Nuisance Alarm Scenarios.

摘要

Experiments were conducted to assess the performance of various residential smoke alarms to kitchen fires and nuisance alarm cooking scenarios. A structure representing a kitchen, living room and hallway was constructed to conduct the experiments. Eight different residential smoke alarms types, two photoelectric models (P1 and P2), two ionization models (I1 and I2), two dual sensor photoelectric/ionization models(D1 and D2), and two multi-sensor, intelligent models (M1 and M2) 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 of alarm technology and installation location on the propensity of an alarm to activate were examined. In the kitchen fire experiments, all smoke alarms responded before hazardous conditions developed. An ionization alarm (I1) tended to respond first compared to other co-located alarms. Results show smoke alarms placed greater than 6 m from the kitchen range may provide less than 120s of available safe egress time, which suggests the importance of a more central alarm location closer to the kitchen for this configuration. Experiments were conducted to determine an alarms propensity to activate when exposed to particulates generated from eight typical cooking activities including toasting, frying, baking and broiling. In most cases, the propensity to nuisance alarm decreased as the distance from the cooking source increased. Two alarms, I1 and D2, experienced more nuisance alarm activations across the eight cooking activities than the other alarms. The remaining alarms experienced about the same combined nuisance alarm frequency by averaging all cooking events for installation locations outside the kitchen. Experiments showed 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 wood-framed, pressboard cabinet can produce a peak heat release rate nearly sufficient to flashover a small room. Alternatively, 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.