Multi-objective optimization of bio-based thermal insulation materials in building modeling

Abstract

Energy efficiency in buildings is a key objective of nowadays policies. To achieve this goal, three main strategies can be implemented: modify users’ behavior, implement passive measures and implement active measures. Those strategies and the reduction of the energy consumption during the use phase imply both, an initial investment and an environmental impact. The equilibrium between them and their efficiency benefits should be evaluated in advance to any intervention. The present work implements a passive measure, an insulation layer in the building envelope, as example. Mathematical programming and multi-objective optimization methodology is used on a building-like cubicle, which energy consumption has been evaluated combining EneryPlus and JEPlus software. Polyurethane and seven commercial and experimental biobased thermal insulation materials are compared. The cost and the environmental impact associated to each solution have been quantified using the life cycle assessment methodology. The results show that bio-based materials can reduce the cost and the environmental impact compared to conventional insulating materials. In our study, hemp offered the most balanced solution, achieving a reduction of 14% and 36% in cost and environmental impact respectively for the climate in Lleida.