Coolingwater from an internal combustion engine is to be cooled from 150 to 110 F. The pressure is 14.7 psia. Compare the following three methods with respect to the air and/or city water required (lb_m/1000 gallons of engine cooling water):

A. Heat transfer to city water. The city water temperature increases from 70 to 130 F.

B. Heat transfer to dry atmospheric air. The air temperature increases from 90 to 120 F.

C. A cooling tower that receives moist air at 90 F with a 50% relative humidity and discharges it at 95 F with 90% relative humidity. The evaporated water is made up by city water at 70 F.