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Life cycle assessment case study of North American residential windows

University of British Columbia

This thesis is a life cycle assessment (LCA) on three window types commonly available to the North American residential consumer: PVC, fiberglass, and wood covered with an aluminum cladding. The LCA was a case study based on the production of the three windows by a single representative manufacturer of each type. Average transportation distances, commodity systems, maintenance, and service life estimations were used to complete the life cycle inventory model. These inventories were grouped into impact categories and scaled based on IMPACT 2002+ v2.1 characterization and damage factors. The damage modeling results indicated that the life cycle impacts are dominated by the combustion of nonrenewable energy resources. Burning fuels cause increased emissions of respiratory inorganics, terrestrial acidification/nutrification impacts, and global warming. The PVC window's life cycle used the most nonrenewable energy and caused the most damage due to that window's shorter service life, 18 years vs. 25 years for fiberglass and aluminum clad wood. This is despite the fact that PVC requires less energy to produce than the fiberglass. The impacts of the steel reinforcement required to strengthen the PVC window outweigh the benefits of the PVC over the fiberglass. The wood window was negatively affected by the addition of aluminum cladding, which required greater energy to manufacture than the wood component. The sensitivity analysis revealed that replacing the virgin material in aluminum cladding with recycled content improved the life cycle impacts of the wooden window. Using fiberglass or PVC to clad the wood window also improved the environmental performance by reducing energy consumption. The use of cladding materials other than aluminum also prevented the disposal of aluminum into municipal landfills which reduced the aquatic ecotoxicity of the wood window's life cycle. Other potential improvements to the impacts of the three windows' life cycles include improving energy efficiency, particularly during secondary manufacturing.

Thesis/Dissertation

application/pdf

2008-06-18

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/919

Forestry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/