5. An air conditioner is used to keep a room at 20°C for an outside temperature of 40°C. Heat taken by the conditioner from the room is 4kW. If its coefficient of performance was 30% that of a reversible refrigerator, find electric power consumption. In order to reduce it, new regulation stipulates that room temperature should be 25°C minimum. Heat power required to be evacuated from the room would be less since it is proportional to temperature difference between outside (40) and inside air (20 or 25). Also, coefficient of performance is improved due to higher room temperature. Find the new electric power consumption due to both effects.
