Method for dynamic thermal insulation design revealing almost real heat transfer characteristics of building envelopes in different Chinese regions

Abstract

The thermal insulation design for building envelopes in winter is traditionally based on steady-state heat transfer, which is the common ground of related building energy efficiency standards in the world. However, its adaptability may be limited to highly dynamic indoor and outdoor thermal environments, especially due to intense solar radiation. This study aims to explore the influence of climatic conditions on the heat transfer of building envelopes and the dynamic thermal insulation (DTI) design method responding to the local climate in China. The actual heat transfer characteristics of residential building envelopes and related factors were investigated based on field tests in two regions. The results showed that in contrast to Guanzhong Plain in Xi’an, strong alternate variations and differences occurred in the heat transfers of building envelopes at different orientations in Tibetan Plateau in Lhasa due to intense solar radiation and large diurnal temperature range. Hence, a DTI design method based on the dynamic heat transfer characteristics is recommended in these areas to maximize solar energy utilization. The outdoor heating supply degree-hours (OHSDH) and outdoor heating supply duration (OHSD) were developed to analyze DTI suitability zoning for 234 cities and towns in China. The optimal zone was identified as Sichuan-Tibet Plateau in Western China with high OHSD and OHSDH values (over 7 h and 95.64 °C·h, respectively). The study findings may provide references for the development of precise climate-responsive design.