Performance evaluation of an air conditioning system with different heights of supply outlet applied to a sleeping environment

Because of the increased expectations on thermal comfort and indoor air quality in sleeping environments at a low energy consumption, it is necessary to develop new air conditioning systems applied to sleeping environments. In recent years, a large number of studies on task/ambient air conditioning (TAC) have been carried out due to its excellent ventilation and energy saving performance. However, compared to full volume air conditioning (FAC), there exists an inadequacy on thermal control for TAC because cooled air is directly delivered to the space around a human body. Hence, the TAC and FAC systems have their own pros and cons in aspects of thermal, ventilation and energy saving performances, and the position of a supply outlet in an air conditioning (A/C) system significantly influences its operating performances. Therefore, a study on the performance evaluations of an A/C system installed in an experimental bedroom with its supply outlet positioned at five different heights has been carried out, and the study results are presented in this paper. The study results suggested that overall speaking, the A/C system performed the best at a supply air temperature of 23 °C, an air flow rate of 50 L/s and a fresh air flow rate of 13 L/s at H1100 setting, among all study cases. On the other hand, the A/C system performed the best at H800 setting among the five height settings.