A Case Study on Passive vs. Active Strategies for an Energy-Efficient School Building Design

This paper presents a simulation study to reduce heating and cooling demand of a school building. This study aims to cross-compare the impact of passive vs. active design on building energy savings. Firstly, the original design of the school building was assessed in terms of heating and cooling energy consumption. Then, the authors made several active energy saving strategies including dynamic blind control, lighting control (dimming), heat recovery ventilator and the use of heat pump. Then, based on the results from the aforementioned simulation study, the authors redesigned the building by changing insulation, windows, and the shape and orientation of the building. It was found that the energy saving of the original design by lighting control is most significant. In addition, the energy savings from the original design to the new design increases by 32%. However, the contribution of the thermal performance improvement of the building envelopes is marginal since the thermal performance of the envelopes of the original design is already good enough. With regard to ventilation, sensible heat & total heat exchangers are very advantageous only in heating season. In intermediate and cooling seasons, their energy saving potential is insignificant. With regard to blind and lighting controls, blind control is less effective than lighting control in heating season. In Intermediate and cooling seasons, blind and lighting controls are very advantageous. When all the active controls are integrated together, total energy savings for the whole building would range from 34.3-48.4%. Finally, it was concluded that energy saving potentials of each room significantly vary depending on room's thermal characteristics (window-wall-ratio, internal heat generation, ventilation requirement) and orientation.