Low energy buildings: multifunctional strategies and solutions

EU directive on the Energy Performance of Buildings states that by 2020 new construction buildings must be Nearly Zero Energy Buildings (NZEB). These are common goals for the EU, however, it creates a challenge for northern countries where climate requests higher energy efficiency materials and respectively the costs. NZEB achieves low energy consumption, solar gains, and reduces heat losses, therefore, has very high energy performance. Passive solar heat gains and its utilization is widely used to reduce energy consumption, especially, through windows in the South façade. Research and experiments of solar simulation models deliver results that allow evaluating potential gains from solar thermal façade systems; in addition, it reduces heat losses for buildings to reach the requirements of NZEB. The goal of the research is to assess latent and sensible energy storage in building envelopes using phase change material (PCM) as a heat accumulator and Fresnel lens as a solar concentrator. A new passive solar thermal façade system model is designed that consists of a Fresnel lens as solar concentrator, PCM as heat accumulator, and copper as heat transfer enhancer to accumulate thermal energy received from the Sun or solar simulator. This research is an example that biology can be integrated with architecture via biomimicry principles and nature has countless multi-functional, complex, and highly responsive mechanisms, strategies, and solutions. Biomimicry in architecture remedies existing errors of efficient system design and products, by taking into the fact that outer shells in nature face the same weather conditions and have the same functions and tasks as reducing heat loss via thermal envelope (insulation, metabolism, hibernation), storing and generating energy, avoiding indoor from overheating.