An office building requires an average heating power of 15kW during winter. Two alternatives are considered:
• Option A: an electrical resistance heater with 100% efficiency;
• Option B: a heat pump that operates between outdoor air at 275K and indoor air at 295K and follows the reversible limit.
(i) Calculate the coefficient of performance of the heat pump under the given temperature conditions.
(ii) Using the relation obtained in Question 4, state what its COP would be if the same unit were run as a refrigerator between the same reservoirs.
(iii) Determine the electrical power input required for Option B to meet the 15kW heating demand.
(iv) Compare the monthly electrical energy consumption (in kWh) for Options A and B if the system runs 10 hours per day for 30 days, and compute the percentage saving achieved with the heat pump.
(v) Discuss briefly one economic and one environmental advantage of choosing Option B on the basis of your calculations.