Life Cycle ASsessment of Phase Change Material Applications in Auckland Home for Energy Efficiency

Abstract

This life cycle assessment (LCA) looks into the environmental impact of using phase change materials (PCM) as a thermal storage unit to reduce the amount of electricity used in home heating and cooling in the Auckland region. The LCA is conducted on a "cradle-to-grave" basis, including the raw materials extraction/collection phase, the usage phase, and the waste and disposal phase as the final stage. Conducted as a comparison LCA, two different types of PCM, paraffin and used cooking oil, impregnated into gypsum board combined with glass wool insulation were modelled and compared to traditional glass wool insulation. As a reference, a base model with no insulation was used. Each model goes through the life cycle of a house from a raw materials extraction/collect phase, to a usage phase, through to a disposal phase. Each model also accounts for transport of goods and waste. The models assess the environmental impact of building one house in the Auckland region over a life span of 40, 60, and 80 years. The methodology used is Eco-Indicator 99, which specifies three damage categories to be human health, resources, and ecosystem quality. Within these 3 damage categories there are 11 addition impact categories. These impact categories are assessed both individually and combined to evaluate the overall impact on the environment. The results show that using PCMs made from used cooking oil combined with glass wool in house construction has approximately a 20% lower overall impact on the environment when compared to traditional glass wool insulation, and nearly a 30% reduction in impact points over a house with no insulation at all. Paraffin-based PCM never achieves significant impact savings in comparison to used cooking oil PCM and would not be an ideal candidate.