Full-scale experimental studies for backdraft using solid materials

The backdraft experiments involved three full-scale room fire tests that used solid furnishing, loveseats. From experimental data, a backdraft caused two temperature peaks. The first one was below 600 °C. Then, an abrupt opening of the front door led to a supply of a large amount of fresh air, followed by an indication of sudden temperature rise. The second peak temperature was over 600 °C. Meanwhile, the deflagration resulted in the gases heating and expanding within the fire space, thus forcing unburned gases out of the vent ahead of the flame front. Comparing both cases with natural gas and solid loveseat as the fuel in backdraft, the former can achieve pre-mixture state and readily create an instant explosion wave phenomenon; however, this wave disappeared immediately. On the other hand, the solid loveseat used as the fuel in this study produced backdraft within 30–50 s after opening of the door. After the occurrence of backdraft, fire maintained a period of fully developed stage, which was consistent with the conditions in actual fires.