Reference no: EM132519302

Question 1. Hot gases at 480°C from a fire are flowing past a plasterboard wall whose exposed surface has already been heated to 118°C. How much convective heat energy is transferred from the hot gases to the wall per square metre if the heat transfer coefficient is 15W/K m²?

Question 2. From the question above, if the effective emissivity of the hot gases is 0.8 and the emissivity of the plasterboard wall is 0.9 in the above question, how much net radiant energy is transferred per square metre to the wall?

Question 3. A room with a flashover fire has a window 1.6 m high and 2.2 m wide which is emitting radiant heat at a mean value of 112 kW/m². What is the maximum radiant heat flux that would be received at the property boundary 1 m away assuming that the window is a black-body?

Question 4. A fire is burning near the corner of a 4mx4m room having a ceiling height of 3.0m. The fire is ventilated through an open doorway where hot gases low out of the room and cold air flows into the room. There is an upholstered lounge suite in the centre of the one side of the room that can be assumed to ignite in a relatively short period of time when exposed to a radiant heat flux of 18kW/m². What temperature would the hot gases beneath the ceiling need to be for the lounge suite to ignite? Assume that the hot layer has an emissivity of 0.9 and that the hot layer is 2.0m above the top of the lounge suite.