Passive cooling control strategies for energy efficency in a subtropical climate air conditioned building

The effect of changing control strategies of mechanical ventilation and air conditioning (MVAC) systems is usually difficult to predict as MVAC processes are non-linear and characteristics of energy consumption change on a seasonal basis. This study investigates how energy consumption can be reduced by defining change in control strategies and tuning the control loops. DesignBuilder based on EnergyPlus, the newest energy simulation software, is used to evaluate the potential energy savings of different passive cooling control strategies. An energy performance baseline model is developed and the influences of demand shifting strategies are investigated progressively round the year. Pre-cooling and economiser control strategies are compared with the baseline energy model. The simulation results show that savings of up to 446MWh can be achieved by implementing pre-cooling control strategies and 123MWh by implementing economiser control strategies. Normalised performance indices are computed to reach a better understanding of each control strategy. The thermal comfort index shows that occupants’ comfort is not hampered, while the building is occupied, under all control strategies.