Potential applicability of dynamic thermal insulation design for building envelopes in different climatic regions of China

An appropriate design method is crucial for addressing the varying building insulation demands in different climatic regions. Compared to the mainstream steady-state thermal insulation (STI) design in winter, the dynamic thermal insulation (DTI) design may offer higher design accuracy and enhanced solar energy utilization, but it increases operational complexity. This study uses the STI method as a reference to explore the extensive application potential of the DTI method across various climatic regions of China. Firstly, after simplifying the operation procedure of the existing DTI method, the minimum thermal resistance, interior surface temperatures, and non-guaranteed duration of building external walls, designed using the STI and DTI methods, are obtained and compared in Lhasa through numerical calculation and dynamic simulation. Furthermore, 10 typical cities with high insulation needs are chosen to analyze the application effects of both design methods. The results show that the DTI method, compared to the STI method, not only significantly enhances wall insulation performance and indoor thermal uniformity in Lhasa, but also exhibits superior multi-dimensional application effects in energy conservation, material efficiency, carbon reduction, and cost saving across various cities. These enhancement effects positively correlate with the grading of cities’ suitability for DTI design. Especially in the optimal zone, the maximum difference ratio of energy saving, carbon saving, total cost saving, and material saving can surpass 19%, 15%, 10% and 6.05%, respectively. Finally, this paper introduces an auxiliary indicator to optimize suitability zoning for DTI design, resulting in four main zones and seven sub-zones. This research can guide architects to appropriately choose and apply the DTI design method in various climatic regions of China.