Life cycle assessment of the inclusion of phase change materials in lightweight buildings

This research evaluates environmental impact of including phase change materials in the envelope of lightweight buildings constructed off-site with dimensions 2.5 x 2.5 x 2.43 m(3), located in the cities of Antofagasta and Calama, both in Chile. These cities are located in a cold desert climate zone, corresponding to a Koppen Climate Classification subtype "BWk", with an average annual temperature difference of 4.8 degrees C. To evaluate the environmental impact quantitatively from "cradle to grave" life cycle assessment was used, it is a methodology based on International Organization for Standardization 14,040 and 14,044 standards. With this methodology, the manufacturing and operational phases and environmental payback period were evaluated. Results show that phase change materials addition in walls and roof of a building decreases electric energy (52.8 % in Antofagasta and 36.3 % in Calama) consumption and environmental impact while in operation, corresponding to 51.4 % and 84.4 % in the cities of Antofagasta and Calama, respectively. In addition, cubicles with phase change materials exhibit an environmental payback period below 15 %. Therefore, a decision of using phase change materials for lightweight buildings could be made in any subtype "BWk" area of Koppen climate classification.