Application of synergic evidence-based design and sustainable technology strategies in off-grid residential NZEBs in the severe cold zone of China: A case study of the Steppe Ark

Abstract

Based on synergic evidence-based design principles, building practices can achieve sustainable benefits throughout the life cycle. Taking example of an off-grid residential nearly zero energy building (NZEB) in China's severe cold zone, the application and sustainability assessment of sustainable technologies can be comprehensively achieved through a closed-loop process: preliminary research, technology development & evaluation, on-site construction and feedback & optimisation. The Steppe Ark is one of such a residential building that takes synergic evidence-based design strategies, proposing and validating three types of technology strategies: integrated design of space based on function and performance, high performance passive technology and efficient active technology. The results show that: (1) the NZEB-oriented building envelope improves the thermal stability of the building, with indoor temperatures decreasing by only 0.07°C per hour when no equipment in operation; (2) the variable multifunctional façade and daylight reflectors have good lighting and insulation energy efficiency, with a combined energy saving rate of 22.1%; (3) Flat gravity heat pipes and thermal storage materials (bricks and PCM) have good performance in terms of heat storage and release. The average indoor daytime temperature can be increased by 3.80°C; the daily temperature difference can be reduced by 52.85% compared to the control group; (4) Stirling motors generate electricity while utilizing the waste heat for the building's floor heating system; (5) the 5.5kWp BIPV system can generate 6.65MWh of electricity per year. This study proposes a pathway for assessing the suitability of building technology through synergic evidence-based design principles. The analysis shows that three types of technology strategies in off-grid residential NZEBs in the severe cold zone of China can achieve good environmental and economically sustainable benefits.