A heat pump is to be used for heating a house in winter. The house is to be maintained at 78°F at all times. When the8)temperature outdoors drops to 25°F,

the heat losses from the house are estimated to be 70,000 Btu/h. Determine the minimum power required to run this heat pump if heat is extracted from (a) the outdoor air at 25°F and (b) the well water at 50°F.