DeST-based dynamic simulation and energy efficiency retrofit analysis of commercial buildings in the hot summer/cold winter zone of China: A case in Nanjing

Computer simulation is an effective tool for predicting building performance under various conditions and for providing a theoretical basis for retrofits that provide cost-effective energy savings. The annual hourly energy consumption of an office building in Nanjing was investigated using the Designer's Simulation Toolkit (DeST). The effects of the thermal performance of the building envelope and outer windows, the fresh air volume, the occupants and the illumination on the building's air conditioning load were studied. Effective energy-saving measures were proposed based on the building characteristics; these measures included an additional insulation layer inside the external walls, changing the material used in the outer windows from 6 mm single-pane glass to low-emissivity (Low-E) glass, reducing the fresh air volume, using independent dehumidification, installing light-emitting diode (LED) lights, and using night-time ventilation. The effectiveness and feasibility of these measures were examined using DeST.