Energetic effects of flow-through wall elements with phase-change materials for building component activation.

The energy efficiency of buildings is important. In order to reduce the energy demand for heating and cooling, a previously proposed flow-through wall element is enhanced with phase-change materials (PCM). By means of numerical modelling and simulation, the energetic effects of the wall element are studied for different cities (i.e., climatic conditions), flow speeds through the wall element, and phase-fraction as well as properties of the phase-change material. Simulations at sufficiently small time steps for an entire year allow to determine the maximum heating and cooling loads, with their respective annual energies by integration. The results revealed that the PCM-enhanced wall element is beneficial for most of the conditions and cities. Especially, the cooling loads can be reduced significantly compared to wall elements without PCM. The annual primary energy consumption, comprising heating, cooling and operation of the wall element has a minimum at flow speeds of approx. 1 m/s.