Volume 15: Low Carbon Cities and Urban Energy Systems: Part IV

An Evaluation on the Effect of Thermal Mass to Modulate Overheating in the Cold Climate in China and the Role of Shading Devices and Night Ventilation Hao Sun, John Calautit, Carlos Jimenez-Bescos

Abstract

Overheating in buildings is a growing challenge in the context of climate change and global warming. Many researchers are focusing on developing different passive strategies to minimize overheating and cooling electrical consumption in buildings. Thermal mass provides thermal energy storage, which could be utilized to store extra heat during hot summers to avoid overheating. To fulfil the cyclical behaviour of the thermal mass, it must be discharged to store heat again and follow this charging-discharging process on a daily basis to modulate overheating. Night ventilation performs the discharging phenomenon to maximize the effect of the thermal mass. Shading devices prevent the penetration of solar radiation into the building in summer. The aim of this study was to evaluate the effect of thermal mass and night ventilation to modulate overheating in the cold climates in Beijing, China. A model of the BESTEST ASHRAE Standard 140 Case 600FF was used to perform full-year dynamic building simulations with Energyplus at different levels of thermal mass. The results allow optimizing the thermal mass configuration according to each climatic condition and in accordance with the performance of night ventilation and shading devices availability. The results confirm the important role played of night ventilation and shading devices to modulate overheating with the potential to reduce maximum temperatures up to 20% by using heavyweight thermal mass compared to lightweight. The results of this study will help to develop the decision support systems to inform the implementation of thermal mass into regional and local building regulations.

Keywords Thermal mass, Night ventilation, Shading devices, Overheating, Future weather