Evaluation and optimization of air-conditioner energy saving control considering indoor thermal comfort

For the purpose of reducing the room air-conditioners’ energy consumption, an energy saving control method is proposed formerly. In this paper its energy saving effect is confirmed through experiments conducted in six office rooms in actual use. The experiment results show that the air-conditioners controlled by the present energy saving control logic and parameter settings can save electric power up to 3.0% compared to ordinary control. Further, if the energy saving control parameters of room temperature set points are fixed at 27oC for cooling operation in summer and at 23oC for heating operation in winter, in average 18.7% and 23.8% electric power can be saved. At the same time, in order to check whether the indoor air temperature of 27oC in summer and 23oC in winter will cause uncomfortable complaints or not, questionnaires on indoor thermal comfort and sensation are conducted. The results show that these indoor temperatures are acceptable for the occupants. Finally a room model and the air-conditioner control model are developed to simulate the performance of one-minute interval room air temperature, which is used to determine on/off status of air-conditioners for the purpose of calculating electric power consumptions. The models finally are used to find out the optimal control parameter settings. The results show that the operation at optimal control set points can save 28.9% energy compared to the ordinary operation.