An advertisement is noted in a rural newspaper for a dairy-barn unit that combine* a milk cooler with a water heater. Milk must, of course, be refrigerated, and hot water is required for washing purposes. The usual bam is equipped with a conventional air-cooled electric refrigerator and an electric-resistance waiter heater. The new unit is said to provide both the necessary refrigeration and the required hot water at a cost for electricity about the same as the cost of running just the refrigerator in the usual installation. To assess this claim, compare two refrigeration units: The advertised unit takes 50,000(Btu)(hr)-1 from a milk cooler at 30(°F). and discards heal through a condenser at 150(°F) to raise the temperature of water from 56 to I46(°F). The conventional unit lakes the same amount of heat from the same milk cooler at 30(°F) and discards heal through an air-cooled condenser at 120(°F); in addition, the same amount of water is heated electrically from 56 to I46(°F) Estimate the total electric power requirements for the two cases, assuming that the actual work in both is 50% greater than required by Carnot refrigerators operating between the given temperatures.