Using annual building energy analysis for the sizing of cooling tower for optimal chiller-cooling energy performance

Lower condenser water temperature is an important factor for water chiller energy performance. In contrary to the usual consideration of trade off between cooling tower fan power and chiller power consumption, this study investigated the effects of oversized cooling tower on the total chiller-cooling tower energy performance. A dynamic building energy method was used in this study to compare the annual energy performance with this strategy using an office building under typical climatic conditions of tropical and subtropical regions. It has been found that oversizing cooling tower would result in ever decreasing total annual energy consumption for chillers and cooling towers as a whole. These result were obtained with different control methods used for the cooling tower falls. Moreover, this rate of decrease in total energy consumption is steepest at 10% oversize of cooling tower at standard conditions. Discussion is presented on the analysis for understanding the principles behind the results thus obtained.