Ventilative cooling of residential buildings in China: A simulation-based evaluation of lightweight modular integrated constructions considering climate change

Ventilative cooling technology is crucial for achieving low-carbon and resilient buildings, but there is a lack of systematical investigations on its energy performance in emerging lightweight modular integrated constructions (MIC). A residential building model was employed to examine the load demands of lightweight (LWC) and heavyweight constructions (HWC) under five climate zones of China. The impacts of envelope thermal transmittance and ventilative cooling on energy demand were evaluated, not only considering current climate conditions but also extending the assessment to the future weather conditions. The results emphasize the importance of thermal mass in nearly-zero energy building standards. Without implementing ventilative cooling, LWC that meets the same energy-efficiency standards as HWC exhibits lower annual load demand than HWC in all climate zones excluding the mild zone, and the energy-saving benefit can be further enhanced by climate change. There is a turning point of the airflow rate of ventilative cooling, where the cooling demand of LWC exceeds that of HWC, and the value of this turning point increases with climate change. The most economical airflow rate of mechanically ventilative cooling is lower in LWC than HWC excluding the mild zone, and this airflow rate is expected to increase with climate change and reduced energy efficiency of the mechanical cooling system. This study provides valuable insights into advancing MIC towards low-carbon goals.