A commercial heat pump is used to maintain a building at 75 $^\circ$F when the average outside temperature is 88 $^\circ$F. Because of heat leaking through the walls and fenestrations, this will require a cooling load of 55000 Btu/hr. In order to receive an Energy Star rating by the Environmental Protection Agency (EPA), heat pumps of this size must have a seasonal average efficiency value (called SEER) of at least 13. That is equivalent to an average COP of 3.277.

(a) Assuming that the COP is constant during the entire season, and that the average price for electricity is $ 0.048 per kWh, how much will it cost to run the unit for 7 hours per day for 30 days under these temperature and load conditions?

$

(b) If the heat pump had no irreversibilities at all, what would be the cost?

(HINT: you need to determine what COP this would yield)

$