A heat pump is to be used to heat a house in winter and then reversed to cool the house in summer. The interior temperature is to be maintained at 70 F. Heat transfer through the walls and roof is estimated to be 1400 Btu/hr per degree temperature difference between the inside and outside.

A. If the outside temperature in winter is 35 F, determine the minimum power (Btu/hr) required to drive the heat pump.

B. If the power input is the same as in Part A, determine the maximum outside temperature (F) for which the inside can be maintained at 70 F.

C. If the outside temperature in winter is 35 F, and the house is to be heated electrically, determine the power (kW) required.