Saiz Susana, Kennedy Christopher, Bass Brad, Pressnail Kim
Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, Canada M5S 1A4.
Environ Sci Technol. 2006 Jul 1;40(13):4312-6. doi: 10.1021/es0517522.
Life cycle assessment (LCA) is used to evaluate the benefits, primarily from reduced energy consumption, resulting from the addition of a green roof to an eight story residential building in Madrid. Building energy use is simulated and a bottom-up LCA is conducted assuming a 50 year building life. The key property of a green roof is its low solar absorptance, which causes lower surface temperature, thereby reducing the heat flux through the roof. Savings in annual energy use are just over 1%, but summer cooling load is reduced by over 6% and reductions in peak hour cooling load in the upper floors reach 25%. By replacing the common flat roof with a green roof, environmental impacts are reduced by between 1.0 and 5.3%. Similar reductions might be achieved by using a white roof with additional insulation for winter, but more substantial reductions are achieved if common use of green roofs leads to reductions in the urban heat island.
生命周期评估（LCA）用于评估在马德里一座八层住宅楼加建绿色屋顶所带来的益处，主要体现在能源消耗的减少。对建筑能耗进行模拟，并在假设建筑寿命为50年的情况下进行自下而上的生命周期评估。绿色屋顶的关键特性是其低太阳吸收率，这会导致较低的表面温度，从而减少通过屋顶的热通量。年能源使用量节省略超过1%，但夏季制冷负荷减少超过6%，上层的高峰时段制冷负荷减少达25%。用绿色屋顶取代普通平屋顶，环境影响可降低1.0%至5.3%。如果使用冬季额外保温的白色屋顶，可能会实现类似的减少，但如果绿色屋顶的普遍使用能减少城市热岛效应，则可实现更大幅度的减少。
