A 1000 ft long metal duct is used to transport heated air from one side of a plant to another. The duct is 24in high by 36in wide. The heated air's temperature at the inlet of the duct is 170 F and the volumetric flow rate is 15,000 CFM. If the ambient air is 74 F and the heat transfer coefficient on the outside of the duct is 1 BTU/hrAft2R, determine the temperature of the air at the outlet of the duct.