1. Consider an atrium inside a shopping mall with an area of 750 m and a height of 21.6 m (6 floors 3.6 m). During a sales season, there are temporary shopping booths and each of them measures 2.5 m by 4 m. During the fire outbreak, one of the booths starts to burn at a fast growth rate until the whole booth is on fire (@500 kW/m). 1 minute after the fire has started, the optical beam detection system activated the mechanical smoke exhaust fan to purge away the smoke at the ceiling. At the same time, the fire shutters are activated at all the upper floors, except the lowest floor, to separate the balcony of the shopping mall from the atrium. The fan is designed to run at constant flowrate to limit the bottom of the smoke layer to be above 20% of the atrium height based on a constant fire size of 5MW. By considering the smoke generation and the smoke exhaust rate against time t (in time steps in 1 minute or 30 seconds), try to use an excel spreadsheet to evaluate the fire size, the smoke mass generation rate, the drop of the smoke layer, and the temperature of the smoke layer against time until it is at steady state. Please state any engineering assumptions taken.