High performance building envelope for climate resilient buildings

建筑围护结构抵抗气候荷载的有效性决定了建筑的性能和耐久性、能源消耗以及实现净零/零+能源状态的程度。风致降雨(WDR)和径流造成的湿气侵入是导致许多建筑围护结构损坏的主要湿气来源，并经常导致昂贵的维修费用，例如温哥华地区的公寓漏水。随着气候的变化，更高的温度和太阳辐射，更强的风和更多的降雨量，预计会有更频繁的风暴和极端天气事件。由于气候变化和可能增加的湿气损害风险，预计立面上的WDR数量将会增加。今天建造和翻新的建筑需要对气候变化具有弹性。 这项研究的重点是1)增进对WDR及其在未来气候下对建筑围护结构影响的理解；2)开发适合其预期小气候的建筑围护结构设计模型、设计工具和指南；3)开发气候适应性强的建筑围护结构改造解决方案。这项拟议的研究是建立在申请人之前成功研究“风致降雨及其对建筑围护结构的影响”的基础上的，该研究生成了加拿大不同地区大量建筑物的独特现场WDR数据，建立了量化悬挑效果的经验关联和经过验证的CFD WDR模型。这些研究工作已经产生了一套关于ISO规定的建议，以便更准确地量化立面上的WDR。申请人还开发了一种随机建模方法，该方法考虑了各种不确定因素，以便更好地评估建筑围护结构的潮湿风险。这些研究成果对于防止建筑围护结构过早失效、影响与建筑围护结构耐久性相关的建筑规范和标准以及应对气候变化具有重要意义。 拟议的研究计划将涉及在建模、实验室测试和现场测量之间取得平衡。该方法将包括：i)对立面径流进行实验室和现场测量，并结合建模，以更好地预测立面上的WDR负荷；ii)制定方法，以便更好地评估未来气候下建筑围护结构的潮湿风险；iii)为适应气候变化的建筑围护结构系统开发设计工具和指南；以及iv)开发成本效益高的预先设计的建筑围护结构系统，这些系统既能发电，又经久耐用，可用于翻新。 拟议的研究计划将支持加拿大政府将气候弹性纳入建筑设计、规范和指南的努力，为加拿大减少温室气体排放的国家目标做出贡献，并培训下一代建筑工程师和专业人员有效处理与气候相关的问题。

The effectiveness of the building envelope to resist climatic loads determines the performance and durability of the building, its energy consumption, and the extent to which its net-zero/plus energy status can be achieved. Moisture intrusion by wind-driven rain (WDR) and runoffs is the major source of moisture causing many building envelope failures and often results in costly repairs, such as the case of leaky condominium in Vancouver area. With a changing climate, higher temperature and solar radiation, stronger wind and higher amount of precipitation, more frequent storms and extreme weather events are expected. Higher WDR amount on façade caused by climate change and potentially increased moisture damage risks would be expected. Buildings built and retrofitted today need to be resilient to climate change. The focus of this research is to 1) advance the understanding of WDR and its impact on building envelopes under future climates; 2) develop models, design tools and guidelines for designing building envelopes suitable for their intended microclimate and 3) develop climate resilient building envelope solutions for retrofits. The proposed research built upon the applicant's successful previous research on “Wind-driven rain and its impact on building envelopes”, which has generated unique field WDR data on a large number of buildings in different regions of Canada, established empirical correlations for quantifying the effectiveness of overhang and a validated CFD WDR model. These research efforts have led to a set of recommendations on ISO provisions for more accurate quantification of WDR on façade. The applicant has also developed a stochastic modeling approach that takes into account a variety of uncertainties for a better assessment of moisture risks of building envelope. These research outcomes are important in preventing premature building envelope failures, impacting on building codes and standards related to building envelope durability, and addressing climate change. The proposed research program will involve a balance between modeling, laboratory testing and field measurements. The methodology will include: i) laboratory and field measurements of façade runoff combined with modeling to better predict the WDR load on façade; ii) development of methodology for better assessment of moisture risks of building envelopes under future climates, iii) development of design tools and guidelines for climate resilient building envelope systems; and iv) development of cost effective and pre-engineered building envelope systems that are energy generating and durable for retrofits. The proposed research program will support Canadian government's effort in integrating climate resiliency into building design, codes and guides, contribute to Canada's national objectives for the reduction of the GHG emission, and train the next generation of building engineers and professionals in effectively dealing with climate related issues.