啟動室內空調對空間進行降溫，若考慮空間中人數及所在位置，以改變空調的運作模式，即可減省空調所需能源。本研究將利用計算流體力學(CFD)的方法，以改變出風口開啟數量，配合不同出風流速、溫度及角度，探討冷卻目標物的所在位置變化如：出風口正下方、兩個出風口之間、四個出風口之間，觀察熱舒適度的影響程度。 出風口正下方的區域降溫，使目標區域達到舒適範圍且節省能源，以單一出風口表現較佳，因為多開啟出風口，使流場中的渦流變多，提高冷熱空氣混合，造成目標區域熱舒適度值偏高。另外以出風口、回風口與室內之溫度差及流量估算空調能源損耗，在兩個出風口之間的區域降溫，同樣維持目標區域在舒適範圍，挑選較節省能源的參數，以單一出風口配合出風角度表現較佳，而在四個出風口之間則以雙出風口配合出風角度表現較佳。 考量熱舒適度計算中的流速、溫度兩個變數，以改變出風口溫度對熱舒適度影響較大，且降低出風口溫度比降低流速節省的能源來得多。而空調運作初期以出風口低流速、低溫下較節省能源，長時間以提高出風口流速、溫度較節能。 The cooling of space depends on the configuration of the air conditioners. Considering the numbers of persons and their positions, we can change the mode of operation to reduce the energy consumption. In this study, the computational fluid dynamics (CFD) methods are used to analyze the influences of thermal comfort on the cooling target at different locations, such as, the location under inlet, the location between two inlets and the location on the center of four inlets by various working parameters, such as: the numbers of inlets at different velocities and temperature. When the cooling target is under the inlet, results show that a single inlet is better to yield better thermal comfort and reduce energy cost. This is beacause that the increasing of the number of air inlet generates lots of turbulence in the flow field, which mix hot and cold air and therefore cause the deterioration of thermal comfort. The assessment of energy efficiency depends on the temperature and velocity in inlet, outlet, and the inside environment. When the cooling target is in the location bwtween two inlets, the best way for the target to maintain the same thermal comfort level but reduce the energy comsuption is to open one inlet with a certain angle. When the target is on the center of the four inlets, it is better to open two inlets with certain angles to yield better thermal comfort and reduce energy comsuption. Comparing the influences of velocity and temperature on thermal comfort, by it is found that the temperature of the inlet has larger impact than the velocity of the inlet. Withing the thermal comfort region, reducing the inlet temperature will save the energy comsumption more than reducing the inlet velocity. For the purpose of reducing the energy comsuption, the best way is to feed air with low temperature and low velocity in the beginning, and then feed air with a higher temperature and velocity after the temperature reaching a certain value.
