Consider a large classroom with 90 students on a hot summer day. All the lights with 2.0 kW of rated power are kept on. The room has no external walls, and thus heat gain through the walls and the roof is negligible. Chilled air is available at 15°C, and the temperature of the return air is not to exceed 25°C. The average rate of metabolic heat generation by a person sitting or doing light work is 115 W (70 W sensible and 45 W latent). Determine the required flow rate of air that needs to be supplied to the room.