The Implementation of Phase Changing Materials in Energy-efficient Buildings. Case Study: EFdeN Project
Abstract The EFdeN Project is a research and educational project which has represented Romania at Solar Decathlon Europe 2014 from Versailles, France. The team has consisted of more than 60 students and university researchers from several Romanian universities. The competition involves the participation in ten other sub-contests: architecture, engineering, energy efficiency, electrical energy balance, comfort conditions, house functioning, communication and social awareness, urbanism, innovation and sustainability. In order to obtain the highest score on energy efficiency, electrical energy balance, comfort conditions, innovation and sustainability sub-contests, the EFdeN Project proposed the implementation of several active and passive strategies. These performant and innovative strategies were designed in order to obtain the perfect indoor conditions with minimum energy consumption. One of the most innovative solutions implemented in the EFdeN prothotype was the integration of phase changing materials (PCM) in the building walls. It was determined, by using dynamic simulations, that the impact of PCM type M27/Q23 on the energy reduction for cooling is around 16.72%, while for the heating is negligible. This material has a latent heat storage value of 85 Wh/m 2 and a phase change temperature of 23C. We have conducted other tests with different PCM materials and the best one was found to be the PCM type M182/Q23, with a latent heat storage of 574 Wh/m 2 and which had a great impact on the energy reduction: cooling 48% and heating 11%. The energy reduction for different types and amounts of PCM can greatly vary for an energy positive house based on variable scenarios (occupancy, ventilation rate, internal gains and temperatures set-points).