7. The following data refer to an air-conditioning system of a cinema hall for winter conditions: Outdoor conditions Required comfort conditions Seating capacity Amount of outdoor air supplied = 10°C DBT, 60% RH = 22°C DBT, 60% RH = 2000 = 0.25 m³/min/person The required condition is achieved by heating, humidifying and then again by heating. The air coming out of the humidifier is having 75% relative humidity. Find: (a) the heating capacity of the first heater in kW and the surface temperature of the coil if its by-pass factor is 0.3; (b) the capacity of the humidifier in kg/h; and (c) the heating capacity of the second heater and its by-pass factor, if the surface temperature of the coil is 25°C. [Ans. 220 kW, 40°C; 200 kg/h; 47.3 kW, 0.44]