The electric heating systems used in many houses consist of a simple duct with electrical resistance wires. Air is heated as it flows over the wires while a current passes through. Consider a 15-kW electric heating system. Air enters the heating section at 100 kPa and 17 C with a volumetric flow rate of 2.5 m3/s. If air leaves the duct at 22 C, determine the heat that was lost from the air to the surroundings in WATTS.