Question

We would like to have a simple model to describe how temperature changes with time in your classroom during lecture in a typical day in Fall and Spring. You can consider two sets of average air temperature – one in October and other one in April for your analysis. Also, for simplicity, consider the entire room to be at one temperature T. Outside air (Ti,) comes in and reaches the temperature of the room through mixing, and this air leaves at the same rate (?). Consider all the possible modes of heat transfer that can take place through the walls (wall resistance), doors, windows (double pane vs single pane), insulation, and as well as metabolic heat generated by us (typically about 60 W per person). Perform an energy balance for the room from which you can calculate the room temperature, T. You need to account for air properties (density of 1.1769 kg/m3and specific heat of 1006 J/kg.K), room, window, and door dimensions. Consider an average air velocity through the doors as 0.1 m/s needed to calculate air flow rate ?. Ignore temperature variation in the air properties in the room. Assume reasonable parameter values needed for numerical calculations. Our goal is to calculate the classroom temperature at the end of a 75 minute lecture? Also makes some observations between cost and energy savings if you plan to incorporate any improvements.

Answer 1