The room in Problem 5.90 has a combined thermal mass of 2000 kg wood, 250 kg steel, and 500 kg plaster board, C_p = 1kJ/kg-K. Estimate how quickly the room heats up if the air conditioner is turned off on a day when it is 35◦C outside.

Data from Problem 5.90

A window air conditioner cools a room at T_L =20◦C with a maximum of 1.2kWpower input. The room gains 0.6 kW per degree temperature difference to the ambient, and the refrigeration COP is β =0.6 βCarnot. Find the maximum outside temperature, T_H, for which the air conditioner provides sufficient cooling.