Life cycle energy assessment and carbon dioxide emissions of wall systems for rural houses

Abstract Wall systems have a wide range of embodied energy due to the diversity of materials available. This paper analyzes the expenditure of energy and carbon dioxide emissions in internal and external wall systems (IEWS) of a rural residence of social interest in Cascavel, state of Paraná, Brazil. The methodology proposed by NBR ISO 14040 was used to perform a life-cycle energy assessment (LCEA) and the carbon dioxide emissions assessment (LCCO2A) of these systems. Four scenarios were considered: reinforced concrete structure and ceramic blocks wall system, load-bearing masonry with concrete blocks, steel framing and reinforced concrete walls molded on site. As a result, it was found that it is possible to reduce energy consumption up to 25% by opting for reinforced concrete walls molded on site. In regards to CO2 emission, it was verified that the difference is even greater, being able to reduce emissions by almost 32% when opting for this same scenario.摘要：墙体系统因可用材料种类多样，其隐含能耗（embodied energy）存在显著差异。本文针对巴西巴拉那州卡斯卡韦尔市一处社会公益性乡村住宅的内外墙体系统（internal and external wall systems, IEWS），展开能源消耗与二氧化碳排放情况的分析。研究采用NBR ISO 14040标准提出的方法，对上述墙体系统开展全生命周期能耗评估（life-cycle energy assessment, LCEA）与全生命周期二氧化碳排放评估（life-cycle carbon dioxide emissions assessment, LCCO2A）。本次研究共设置四类场景：钢筋混凝土结构搭配陶瓷砌块墙体系统、混凝土砌块承重砌体结构、轻钢龙骨（steel framing）墙体体系以及现浇钢筋混凝土墙体。研究结果显示，选用现浇钢筋混凝土墙体方案可将能耗降低最高达25%；在二氧化碳排放方面，减排差异更为显著，采用该方案可使排放量减少近32%。