A classroom that normally contains 40 people is to be air-conditioned with window air-conditioning units of 5 kW cooling capacity. A person at rest may be assumed to dissi- pate heat at a rate of about 80 Watts. There are 10 light bulbs in the room, each with a rating of 100 W. The rate of heat transfer to the classroom through the walls and the windows is estimated to be 15,000 kJ/h.
a. If the room air is to be maintained at a constant temperature of 21°C, determine the number of window air-conditioning units required.
b. What is the source of heat being generated for the light bulbs and for the students?