A classroom that normally contains 40 people is to be air-conditioned with window air conditioning units of 5-kW cooling capacityeach. A person at rest may be assumed to dissipate heat at the rate of about 360 kJ/hr. 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/hr. Ifthe room air is to be maintained at a constant temperature, determine the number of window air conditioning units required.