Thermal behavior of a passive solar wall with silica aerogel and phase change materials

International audienceThe present contribution discusses the thermal behavior of a passive solar wall composed of a glazing facing the outside, a channel filled with highly insulating and translucent silica aerogel, and glass bricks filled with an eutectic phase change material (PCM), facing the inside. First, the experimental building with the tested wall, south-oriented, is described. Second, the experimental results on four different weather conditions are detailed. Thanks to a numerical model, the wall behavior is simulated for the French climatic zones of Nice (Mediterranean climate), La Rochelle (oceanic climate), Embrun (inland mountain climate) and Nancy (cold continental climate). Results show that the wall is translucent and may save 27% to 83 % on the building energy bill for heating, depending on the building location. The wall performs best on cold sunny climates, where the phase change can occur all year. The air temperature inside the building is always 1 to 9°C above the external temperature. Overheating may occur in summer for Mediterranean and oceanic climates when the PCM stays in liquid state. This may be prevented by the use of shading