Optimal Supply Water Temperature Control of Water Source Heat Pump

The water loop supply water temperature is the most critical control parameter for operating energy cost in water source heat pump systems. In this paper, the impact of the water loop temperature on operating energy cost is investigated for different types of buildings under different loads using theoretical models. The theoretical models and approaches are also applied to an 80,000 square feet office building to determine the building heating and cooling load, optimal supply water temperature, and potential energy cost savings based on measured supply water temperature and loop heat gain. It is concluded that the optimal supply water temperature control can significantly reduce the annual energy costs associated with compressor power and boiler energy. The potential energy savings is determined to be 24% in the application building.