The temperatures recorded during the summer and winter in a particular locality are 45 C and 15 C respectively:

a. If air is used as a cooling medium having a temperature difference of 15 C, calculate the COP for heating and COP for cooling of the air-conditioning unit that corresponds to the refrigeration temperatures of 5 C for summer and heating temperature of 55 C for winter.

b. If water is used as a cooling medium instead of air, having a temperature difference of 10 C, calculate the COP for cooling, assuming that cooling water is from a reservoir at 30 C that serves as a cooling medium with a 3 C temperature differential for air-conditioning in summer.

c. compute the theoretical power consumption per ton of refrigeration when using air-cooled and water-cooled refrigeration systems.

d. calculate the percent savings in power when using a water-cooled instead of air-cooled refrigeration system