Currently in China, the building sector is responsible for large energy consumption and corresponding greenhouse gas (GHG) emissions. Especially for the Shanghai area, which shares about 4.2% of the total national building energy consumption, further, above 60% of them are from existing public buildings. There is a high demand that the public buildng sector in Shanghai makes a contribution to the national scheme of promoting slow global warming by the reduction of energy related GHG emssions. Implementing the insulation materials for building external walls is one of the most effective solutions for building operational energy saving. However, although using insulation materials has net positive environment impacts, it still has the negative impacts associated with its energy consumption and greenhouse gas emission during the other life cycle stages.
This study has delivered an assessment of the external wall insulation materials that are used for the existing public building retrofitting in Shanghai area. Four kinds of insulation materials have been chosen in this study including three widely utilized conventional materials in China which are Polyurethane (PUR), Expanded Polystyrene (EPS) and Mineral wool, and also include natural source wood fibre insulation material to assess its potential life cycle performance. Additionally, a life cycle model has been defined under the specific research context for quantifying the life cycle energy consumption and greenhouse gas emission of the selected materials for assessment.
The results of the life cycle study show that not only the product phase, but also the transportation and usage (operation) phases both have considerable impact for the net life time energy and environmental impacts under different scenario. In basis of delivering equally thermal resistance improvement, materials of PUR and EPS are more attractive that present overall higher performance than the other two materials. For the natural sourced wood fibre insulation material, although it has an excellent performance for reducing GHG emissions in the product phase, it does not show a better performance for the net life time energy saving and GHG emission reduction compared with the other three conventional widely utilized insulation materials. And its results also produced a higher sensitivity to various scenarios in transportation and usage (operation) phase.