In extreme climate zones, modular construction requires optimized building envelope systems to achieve a dual improvement in thermal performance and energy efficiency. Its core lies in constructing a dynamic energy-saving system adapted to extreme temperatures, snowstorms, or droughts through structural integration, material innovation, and system synergy. As a crucial interface between the building and its external environment, the building envelope directly impacts indoor thermal comfort and energy consumption. Especially in extreme climates, traditional building envelopes are prone to performance degradation due to thermal expansion and contraction, material aging, or structural defects. Modular construction, through factory prefabrication and standardized design, provides more precise control over building envelope optimization.
Structural integration design is fundamental to improving the thermal performance of the building envelope. In cold climate zones, building envelopes must simultaneously withstand low-temperature contraction and snowstorm loads. Traditional structures are prone to cracking due to uneven material stress. Modular construction, through "structure-envelope integration" design, deeply integrates the support system with the envelope interface. For example, using cable-stayed box-shaped arch structures, the prestressed cables and arched stress characteristics disperse the load, reducing structural deformation and damage to the building envelope. Flexible connections between enclosure modules are achieved through elastic compression pads, which absorb temperature stress and cut off thermal bridges, preventing heat loss due to localized low temperatures. This design allows the enclosure system to maintain continuity under extreme loads, significantly improving airtightness and insulation.
Material innovation is key to optimizing thermal performance. Extreme climate zones place stringent demands on enclosure materials: cold regions require materials with low thermal conductivity to reduce heat transfer, hot regions require materials with high reflectivity to block solar radiation, and arid regions require weather-resistant materials to resist wind and sand erosion. Modular construction, leveraging factory prefabrication, can integrate various new materials, such as embedding vacuum insulation panels (VIP) or aerogel felt in the walls to reduce the heat transfer coefficient, while using phase change materials (PCM) to regulate indoor temperature fluctuations. The window system uses triple-glazed, double-cavity argon-filled insulated glass with low-emissivity (Low-E) coatings to significantly reduce the solar heat gain coefficient (SHGC) while ensuring sufficient natural light, thus reducing air conditioning load.
The coordinated design of the enclosure system and energy system is central to achieving energy-saving effects. Modular construction achieves deep integration of the building envelope with air conditioning, ventilation, and lighting systems through standardized interfaces. For example, in cold-climate modules, the building envelope incorporates heat recovery ventilation ducts, utilizing exhaust waste heat to preheat fresh air and reduce heating energy consumption. In hot-climate modules, adjustable shading louvers on the roof, combined with integrated photovoltaic (BIPV) glass, both block direct sunlight and convert solar energy into electricity for building use. Furthermore, modular design allows for flexible adjustments to the building envelope based on climate zones, such as increasing the wall insulation thickness of cold-climate modules or designing ventilated roofs for hot-climate modules, achieving "one building, multiple climate adaptability."
Air tightness and gap control are crucial details for improving thermal performance. In extreme climates, even tiny gaps can lead to significant heat loss. Modular construction reduces the number of seams in the building envelope through precision factory manufacturing and optimized on-site assembly processes, and uses weather-resistant sealants and airtight strips to seal gaps in critical areas. For example, the vertical joints between the enclosure modules employ a double-seal design, while the horizontal joints are connected by interlocking profiled steel sheets, ensuring a high level of overall airtightness and effectively reducing heat loss caused by air infiltration.
The removability and maintainability of the building envelope extend the building's lifespan and enhance energy efficiency. Extreme climates accelerate material aging, and traditional building envelopes are costly to repair and difficult to upgrade. Modular construction, through standardized connectors and modular structures, allows for the partial replacement of damaged envelope units without the need for complete demolition. For instance, if the insulation layer in a certain area is damaged due to long-term freeze-thaw cycles, the corresponding module can be quickly disassembled and replaced with new insulation material, restoring overall thermal performance. This design reduces long-term maintenance costs and improves the building's adaptability to extreme climates.
Digital technology provides precise support for building envelope optimization. Through Building Information Modeling (BIM) and performance simulation software, the thermal performance of the building envelope under different climatic conditions can be predicted during the design phase, optimizing material combinations and construction details. For example, simulating the heat flow distribution of modules in cold regions under extreme low temperatures allows for adjustments to the insulation layer thickness and cable prestress values; or analyzing the shading effect of modules in hot regions under strong sunlight optimizes louver angles and photovoltaic panel layouts. Digital tools have shifted the optimization of building envelope systems from experience-driven to data-driven, significantly improving design efficiency and energy-saving effects.
From an industry trend perspective, the optimization of modular construction building envelope systems is moving towards a "passive design + active energy management" approach. By reducing energy demand through high-performance building envelopes and optimizing energy use through intelligent control systems, the energy efficiency advantages of modular construction in extreme climate zones will become even more prominent. For example, building envelope systems integrating sensors and IoT technology can monitor indoor and outdoor temperature, humidity, and light intensity in real time, automatically adjusting shading, ventilation, and insulation to achieve dynamic energy savings. This "adaptive building envelope system" will become the core competitiveness of modular construction in future extreme climate zones.
